Tools to transcode, inspect and convert videos.

Hi, I'm Don Melton. I created these tools to transcode my collection of Blu-ray Discs and DVDs into a smaller, more portable format while remaining high enough quality to be mistaken for the originals.

What makes these tools unique are the ratecontrol systems which achieve those goals.

This package is based on my original collection of Video Transcoding Scripts written in Bash. While still available online, those scripts are no longer in active development. Users are encouraged to install this Ruby Gem instead.

Most of the tools in this package are essentially intelligent wrappers around Open Source software like HandBrake, FFmpeg, MKVToolNix, and MP4v2. And they're all designed to be executed from the command line shell:

• transcode-video Transcode video file or disc image directory into format and size similar to popular online downloads.

• detect-crop Detect crop values for video file or disc image directory.

• convert-video Convert video file from Matroska to MP4 format or from MP4 to Matroksa format without transcoding video.

• query-handbrake-log Report information from HandBrake-generated .log files.

Even if you don't try any of my tools, you may find this "README" document helpful:

• About
• Installation
• Rationale
• Usage
• Guide
• Explanation
• FAQ
• History
• Feedback
• Acknowledgements
• License

My Video Transcoding tools are designed to work on macOS, Linux and Windows. They're packaged as a Gem and require Ruby version 2.0 or later. See "Installing Ruby" if you don't have the proper version on your platform.

Use this command to install the package:

gem install video_transcoding

You may need to prefix that command with sudo in some environments:

sudo gem install video_transcoding

Use this command, or the variation prefixed with sudo, to update the package:

gem update video_transcoding

Most of the tools in this package require other software to function properly, specifically these command line programs:

• HandBrakeCLI
• ffmpeg
• mkvpropedit
• mp4track

Previewing the output of detect-crop is optional, but doing so uses mpv, a free, Open Source, and cross-platform media player.

You can download the command line version of HandBrake, called HandBrakeCLI, here:

https://handbrake.fr/downloads2.php

On macOS, HandBrakeCLI and all its other dependencies can be easily installed via Homebrew, an add-on package manager:

brew install handbrake
brew install ffmpeg
brew install mkvtoolnix
brew install mp4v2

The optional crop previewing package can also be installed via Homebrew:

brew install mpv

On Linux, package management systems vary so it's best consult the indexes for those systems. But there's a Homebrew port available called Linuxbrew and it doesn't require root access.

On Windows, it's best to follow one of the two methods, manually installing binaries or installing into the Windows Subsystem for Linux, as described here:

https://github.com/JMoVS/installing_video_transcoding_on_windows

When installing HandBrakeCLI or other downloaded programs, make sure the executable binary is in a directory listed in your PATH environment variable. On Unix-style systems like macOS and Linux, that directory might be /usr/local/bin.

If you're comfortable using Docker virtualization software, a pre-built container with everything you need, plus installation instructions, is available here:

https://hub.docker.com/r/ntodd/video-transcoding/

Videos from the iTunes Store are my template for a portable format while remaining high enough quality to be mistaken for the originals. Their files are very good quality, much smaller than the same video on a Blu-ray Disc, and play on a wide variety of devices.

HandBrake is a powerful video transcoding tool but it's complicated to configure. It has several presets but they aren't smart enough to automatically change bitrate targets and other encoding options based on different inputs. More importantly, HandBrake's default presets don't produce a predictable output size with sufficient quality.

HandBrake's "AppleTV 3" preset is closest to what I want but transcoding "Planet Terror (2007)" with it results in a huge video bitrate of 19.9 Mbps, very near the original of 22.9 Mbps. And transcoding "The Girl with the Dragon Tattoo (2011)," while much smaller in output size, lacks detail compared to the original.

So, the transcode-video tool configures the x264 video encoder within HandBrake to use a modified constrained variable bitrate (CVBR) mode, and to automatically target bitrates appropriate for different input resolutions.

When audio transcoding is required, it's done in AAC format and, if the original is multi-channel surround sound, in Dolby Digital AC-3 format. Meaning the output can contain two tracks from the same source in different formats. And mono, stereo and surround inputs are all handled differently.

But most of these default settings and automatic behaviors can be easily overridden or augmented with additional command line options.

HandBrake applies automatic crop detection by default. While it's usually correct, it does guess wrong often enough not to be trusted without review. For example, HandBrake's default behavior removes the top and bottom 140 pixels from "The Dark Knight (2008)" and "The Hunger Games: Catching Fire (2013)," losing significant portions of their full-frame content.

This is why transcode-video doesn't allow HandBrake to apply cropping by default.

Instead, the detect-crop tool leverages both HandBrake and FFmpeg to find the video cropping bounds. It then indicates whether those two programs agree. To aid in review, this tool prints commands to the terminal console allowing the recommended (or disputed) crop to be displayed, as well as a sample command line for transcode-video itself.

All videos from the iTunes Store are in MP4 format format. However, the transcode-video tool generates output in the more flexible Matroska format by default.

While you can easily change the behavior of transcode-video to generate MP4 format with a command line option, it's sometimes handy to convert between formats quickly without re-transcoding. The convert-video tool is designed for exactly that convenience.

The transcode-video tool creates both video files and .log files. While not nearly as entertaining, the cryptic .log file still contains useful information. And the query-handbrake-log can extract performance metrics, video bitrate and relative quality from those .log files into easily readable reports.

Each of my Video Transcoding tools has several command line options. The transcode-video tool is the most complex with over 40 of its own. Not all of those options are detailed here. Use --help to list the full set of options available for a specific tool, along with brief instructions on their usage:

transcode-video --help

This built-in help works even if a tool's software dependencies are not yet installed.

All of the tools can accept multiple inputs, but batch processing for transcode-video is still best handled by a separate script.

The transcode-video and detect-crop tools work best with video files:

transcode-video "/path/to/Movie.mkv"

However, both tools also accept disc image directories as input:

transcode-video "/path/to/Movie disc image directory/"

Disc image directories contain unencrypted backups of Blu-ray Discs or DVDs. Typically these formats include more than one video title. These additional titles can be bonus features, alternate versions of a movie, multiple TV show episodes, etc.

By default, transcode-video and detect-crop will automatically select the main feature in a disc image directory. Or they will select the first title, if the main feature can't be determined.

Both tools allow you to scan disc image directories, listing titles and tracks:

transcode-video --scan "/path/to/Movie disc image directory/"

So you can then select a specific title by number:

transcode-video --title 5 "/path/to/Movie disc image directory/"

The transcode-video tool automatically determines target video bitrate, number of audio tracks, etc. without any command line options, so using it can be as simple as:

transcode-video "/path/to/Movie.mkv"

That command creates, after a reasonable amount of time, two files in the current working directory:

Movie.mkv
Movie.mkv.log

The .log file can be used as input to the query-handbrake-log tool.

By default, the transcode-video tool generates output in Matroska format. To generate output in MP4 format, use the --mp4 option:

transcode-video --mp4 "/path/to/Movie.mkv"

Which will instead create:

Movie.mp4
Movie.mp4.log

To create MP4 output with the .m4v file extension instead of .mp4, use the --m4v option:

transcode-video --m4v "/path/to/Movie.mkv"

The .m4v file extension is more "iTunes-friendly," but the file content itself is exactly the same as a file with the .mp4 extension.

You can increase encoding speed by 70-80% with no easily perceptible loss in video quality by using the --quick option:

transcode-video --quick "/path/to/Movie.mkv"

The --quick option avoids the typical quality problems associated with the x264 video encoder's speed-based presets, especially as that speed increases.

No cropping is applied by default. Use the --crop TOP:BOTTOM:LEFT:RIGHT option and arguments to indicate the amount of black, non-content border to remove from the edges of your video.

This command removes the top and bottom 144 pixels, typical of a 2.40:1 widescreen movie embedded within 16:9 Blu-ray Disc video:

transcode-video --crop 144:144:0:0 "/path/to/Movie.mkv"

This command removes the left and right 240 pixels, typical of a 4:3 classic TV show embedded within 16:9 Blu-ray Disc video:

transcode-video --crop 0:0:240:240 "/path/to/Movie.mkv"

Use the detect-crop tool to determine the cropping bounds before transcoding.

You can also call the detect-crop logic from transcode-video with the single detect argument:

transcode-video --crop detect "/path/to/Movie.mkv"

However, be aware that detect can fail if HandBrake and FFmpeg disagree about the cropping values.

By default, the transcode-video tool selects the first audio track in the input as the main audio track. This is the first track in the output and the default track for playback.

But you can select any input audio track as the main track. In this case, track number 3:

transcode-video --main-audio 3 "/path/to/Movie.mkv"

Or you can select the first input audio track in a specific language using a three-letter code instead of a track index number. This command selects the first Spanish language track:

transcode-video --main-audio spa "/path/to/Movie.mkv"

If no track in the target language is found, then selection defaults to the first audio track in the input.

You can also give the main audio track a custom name:

transcode-video --main-audio 3="Original Stereo" "/path/to/Movie.mkv"

Unlike HandBrakeCLI, custom track names are allowed to contain commas.

By default, only one track is selected as the main audio or default track. But you can add additional tracks, also with custom names:

transcode-video --add-audio 4 --add-audio 5="Director Commentary" "/path/to/Movie.mkv"

Or you can add all audio tracks with a single option and argument:

transcode-video --add-audio all "/path/to/Movie.mkv"

You can also add audio tracks selected by their three-letter language code. This command adds all French and Spanish language tracks in the same order they're found in the input:

transcode-video --add-audio fra,spa "/path/to/Movie.mkv"

By default, the main audio track is transcoded in AAC format and, if the original is multi-channel surround sound, in Dolby Digital AC-3 format. Meaning the output can contain two tracks from the same source in different formats. So, main audio output is "wide" enough for "double" tracks.

Also by default, any added audio tracks are only transcoded in AAC format. Meaning the output only contains a single track in one format. So, additional audio output is only "wide" enough for "stereo" tracks.

However, you can change the "width" of main audio or additional audio output using the --audio-width option. There are three possible widths: double, surround and stereo.

Use this command to treat any other additional audio tracks just like the main audio track:

transcode-video --audio-width other=double "/path/to/Movie.mkv"

Or use this command to make main audio output as a single track but still allow it in surround format:

transcode-video --audio-width main=surround "/path/to/Movie.mkv"

Please note that tracks transcoded to stereo AAC format, including the main track, are output in matrix-encoded Dolby Pro Logic II surround format when the original input is multi-channel surround sound. This means that even though the AAC stereo track contains only two discrete channels, it can be decoded as multiple channels. So Dolby Digital AC-3 format is not actually required for surround sound output.

If possible, audio is first passed through in its original format, providing that format is either AC-3 or AAC. This hardly ever works for Blu-ray Discs but it often will for DVDs and other random videos.

However, you can still copy audio tracks and maintain their original format, provided HandBrake and your selected file format support it:

transcode-video --copy-audio all "/path/to/Movie.mkv"

The --copy-audio option doesn't implicitly add audio tracks to be copied. Since only the main audio track is included by default, the previous command only tries to copy that track. To also copy another track, you must first add it:

transcode-video --add-audio 4 --copy-audio all "/path/to/Movie.mkv"

Be aware that copying audio tracks in their original format will likely defeat two very important goals of transcoding: portability and compression.

By default, the transcode-video tool automatically burns any forced subtitle track it detects into the output video track. "Burning" means that the subtitle becomes part of the video itself and isn't retained as a separate track. A "forced" subtitle track is detected by a special flag on that track in the input.

But you can select any subtitle track for burning. In this case, track number 3:

transcode-video --burn-subtitle 3 "/path/to/Movie.mkv"

You can also use a special "scan" mode of HandBrake to find any embedded forced subtitle track that's in the same language as the main audio track:

transcode-video --burn-subtitle scan "/path/to/Movie.mkv"

Be aware that using this special "scan" mode does not always work. Sometimes it won't find any track or, worse, it will find the wrong track. And you won't know whether it worked until the transcoding is complete.

Burning subtitles into the output video works best for "forced" rather than optional subtitles. But it's still a much better idea than adding subtitle tracks in their original format to the output file.

Blu-ray Disc and DVD subtitles are bitmap formats. They're not text. They're large, unwieldy and may not appear correctly if you crop your video. Blu-ray Disc-format subtitles aren't even allowed in MP4 output. And DVD-format subtitles, while allowed, often won't display at all in many MP4 players.

However, you can leverage programs like SUBtools or Subtitle Edit to extract Blu-ray Disc and DVD subtitles and convert them into text format. Be aware that while both of these programs can perform automatic character recognition of the subtitle bitmaps, you'll still need to edit the output text by hand. Even the best automatic character recognition is still wrong far too often.

You can also find text-based subtitles for your movies and TV shows at sites like OpenSubtitles, where someone else has already done the tedious work of conversion and editing.

If and when you do have a subtitle in text format, specifically SubRip .srt format, you can easily add it to your output video from an external file:

transcode-video --add-srt "/path/to/Subtitle.srt" "/path/to/Movie.mkv"

Unlike HandBrakeCLI, external subtitle file names are allowed to contain commas.

The command to find the video cropping bounds is as simple as:

detect-crop "/path/to/Movie.mkv"

Which prints out something like this:

mpv --no-audio --vf lavfi=[drawbox=0:132:1920:816:invert:1] '/path/to/Movie.mkv'
mpv --no-audio --vf crop=1920:816:0:132 '/path/to/Movie.mkv'

transcode-video --crop 132:132:0:0 '/path/to/Movie.mkv'

Just copy and paste the sample commands to preview or transcode.

Please note that path names within the sample commands are not escaped properly when using cmd.exe or PowerShell on Windows. If you have Git for Windows or another Unix-like environment installed, you can use the Bash shell (usually named bash.exe) to work around this issue.

If HandBrake and FFmpeg disagree about the cropping values, then detect-crop prints out something like this:

Results differ...

# From HandBrakeCLI:

mpv --no-audio --vf lavfi=[drawbox=0:132:1920:816:invert:1] '/path/to/Movie.mkv'
mpv --no-audio --vf crop=1920:816:0:132 '/path/to/Movie.mkv'

transcode-video --crop 132:132:0:0 '/path/to/Movie.mkv'

# From ffmpeg:

mpv --no-audio --vf lavfi=[drawbox=0:130:1920:820:invert:1] '/path/to/Movie.mkv'
mpv --no-audio --vf crop=1920:820:0:130 '/path/to/Movie.mkv'

transcode-video --crop 130:130:0:0 '/path/to/Movie.mkv'

You'll then need to preview both and decide which to use.

When input is a disc image directory instead of a single file, the detect-crop tool doesn't use FFmpeg, nor does it print out commands to preview the crop.

The convert-video tool repackages video files, converting them from Matroska to MP4 format or from MP4 to Matroksa format without transcoding the video. It's as simple as:

convert-video "Movie.mkv"

Which creates this MP4 file in the current working directory:

Movie.mp4

Or...

convert-video "Movie.mp4"

Which creates this Matroska file in the current working directory:

Movie.mkv

If necessary, the convert-video tool may transcode audio tracks to AAC or Dolby Digital AC-3 format when converting to MP4 format.

Chapter markers, metadata such as track titles and most subtitles are converted. However, be aware that any Blu-ray Disc-format subtitles are ignored.

The query-handbrake-log tool reports information from HandBrake-generated .log files. While it can certainly work with a single .log file, it really shines with multiple files.

There are four types of information that query-handbrake-log can report on:

• time The time spent during transcoding, sorted from short to long. This even works for two-pass transcodings.

• speed The speed of transcoding in frames per second, sorted from fast to slow. Since most video is 23.976 FPS, you can easily see trends when you're faster or slower than real time.

• bitrate The final video bitrate of the transcoded output, sorted from low to high. Very useful since most media query tools only provide approximate bitrates for Matroska files, if at all.

• ratefactor Technically this is the average P-frame quantizer for transcoding, sorted from low to high. But you should consider it a relative quality assessment by the x264 video encoder.

One of these information types is required as an argument:

query-handbrake-log time "/path/to/Logs directory/"

Which prints out something like this, time spent transcoding followed by video file name:

01:20:25 Movie.mkv
01:45:10 Another Movie.mkv
02:15:35 Yet Another Movie.mkv

I have four rules when preparing my own media for transcoding:

1. Use MakeMKV to rip Blu-ray Discs and DVDs.
2. Rip each selected video as a single Matroska format .mkv file.
3. Look for forced subtitles and isolate them in their own track.
4. Convert lossless audio tracks to FLAC format.

• It runs on most desktop computer platforms like macOS, Windows and Linux. There's even a free version available to try before you buy.

• It was designed to decrypt and extract a video track, usually the main feature of a disc and convert it into a single Matroska format .mkv file. And it does this really, really well.

• It can also make an unencrypted backup of your entire Blu-ray or DVD to a disc image directory.

• It's not pretty and it's not particularly easy to use. But once you figure out how it works, you can rip your video exactly the way you want.

• Many automatic behaviors and other features in both transcode-video and detect-crop are not available when input is a disc image directory. This is because that format limits the ability of HandBrakeCLI and ffmpeg to detect or manipulate certain information about the video.

• Both forced subtitle extraction and lossless audio conversion, detailed below, are not possible when input is a disc image directory.

• Remember "The Hunt for Red October (1990)" when Sean Connery and Sam Neill are speaking actual Russian at the beginning of the movie instead of just using cheesy accents like they did the rest of the time? The Blu-ray Disc version provides English subtitles just for those few scenes. They're "forced" on screen for you. Which is actually very convenient.

• Forced subtitles are often embedded within a full subtitle track. And a special flag is set on the portion of that track which is supposed to be forced. MakeMKV can recognize that flag when it converts the video into a single .mkv file. It can even extract just the forced portion of that subtitle into a another separate subtitle track. And it can set a different "forced" flag in the output .mkv file on that separate track so other software can tell what it's for.

• Not all discs with forced subtitles have those subtitles embedded within other tracks. Sometimes they really are separate. But enough discs are designed with the embedded technique that you should avoid using a disc image directory as input for transcoding.

• DTS-HD Master Audio is the most popular high definition, lossless audio format. It's used on more than 80% of all Blu-ray Discs.

• Currently, HandBrake can't decode the lossless portion of a DTS-HD audio track. It's only able to extract the non-HD, lossy core which is in DTS format.

• But MakeMKV can decode DTS-HD and convert it into FLAC format which can then be decoded by HandBrake and most other software. Once again, MakeMKV can only do this when it converts the video into a single .mkv file.

The --preset option in transcode-video controls the x264 video encoder, not the other preset system built into HandBrake. It takes a preset name as its single argument:

transcode-video --preset slow "/path/to/Movie.mkv"

The x264 preset names (mostly) reflect their relative speed compared to the default, medium.

Presets faster than medium trade precision and compression efficiency for more speed. You may notice quality loss problems when using these presets, especially as speed increases.

However, you can increase encoding speed by 70-80% with no easily perceptible loss in video quality by using the --quick option instead:

transcode-video --quick "/path/to/Movie.mkv"

Presets slower than medium trade encoding speed for more precision and compression efficiency. Any quality improvement using these presets may not be perceptible for most input.

A faster and more perceptible way to improve quality is to simply raise the target video bitrate 50% by using the --target big option and argument macro:

transcode-video --target big "/path/to/Movie.mkv"

Use the default settings whenever possible.

Use the --mp4 or --m4v options if your target player can't handle Matroska format.

Use the --quick option if you're in a hurry.

Use detect-crop before transcoding to manually review and apply the best crop values.

Don't add audio tracks in their original format that aren't AAC or Dolby Digital AC-3.

Don't add subtitles in their original Blu-ray Disc or DVD format.

Save your .log files so you can mine the data later.

Although the transcode-video tool can accept multiple inputs, batch processing is still best handled by a separate script because options can be changed for each input.

A batch.sh script can simply be a list of commands:

#!/usr/bin/env bash

transcode-video --crop 132:132:0:0 "/path/to/Movie.mkv"
transcode-video "/path/to/Another Movie.mkv"
transcode-video --crop 0:0:240:240 "/path/to/Yet Another Movie.mkv"

But a better solution is to write the script once and supply the list of movies and their crop values separately:

#!/usr/bin/env bash

readonly work="$(cd "$(dirname "$0")" && pwd)"
readonly queue="$work/queue.txt"
readonly crops="$work/Crops"

input="$(sed -n 1p "$queue")"

while [ "$input" ]; do
    title_name="$(basename "$input" | sed 's/\.[^.]*$//')"
    crop_file="$crops/${title_name}.txt"

    if [ -f "$crop_file" ]; then
        crop_option="--crop $(cat "$crop_file")"
    else
        crop_option=''
    fi

    sed -i '' 1d "$queue" || exit 1

    transcode-video $crop_option "$input"

    input="$(sed -n 1p "$queue")"
done

This requires a work directory on disk with three items, one of which is a directory itself:

batch.sh
Crops/
    Movie.txt
    Yet Another Movie.txt
queue.txt

The contents of Crops/Movie.txt is simply the crop value for /path/to/Movie.mkv:

132:132:0:0

And the contents of queue.txt is just the list of movies, full paths without quotes, delimited by carriage returns:

/path/to/Movie.mkv
/path/to/Another Movie.mkv
/path/to/Yet Another Movie.mkv

Notice that there's no crop file for /path/to/Another Movie.mkv. This is because it doesn't require cropping.

For other options that won't change from input to input, e.g. --mp4, simply augment the line in the script calling transcode-video:

    transcode-video --mp4 $crop_option "$input"

The transcoding process is started by executing the script:

./batch.sh

The path is first deleted from the queue.txt file and then passed as an argument to the transcode-video. tool. To pause after transcode-video returns, simply insert a blank line at the top of the queue.txt file.

These examples are written in Bash and only supply crop values. But almost any scripting language can be used and any option can be changed on a per input basis. Nick Wronski has written a batch-processing wrapper for transcode-video in Node.js, available here:

https://github.com/nwronski/batch-transcode-video

What is a ratecontrol system? It's how a video encoder decides on the amount of bits to allocate for a specific frame.

My transcode-video tool has four different ratecontrol systems which manipulate x264 and three which manipulate x265, both software-based video encoders built into HandBrakeCLI.

Additionally, transcode-video allows access to hardware-based video encoders which have their own ratecontrol systems.

All of these ratecontrol systems, mine and those built into hardware, target a specific video bitrate.

The target video bitrate for all of these systems is automatically determined by transcode-video using the resolution of the input. For example, the default target for 1080p output is 6000 Kbps, which is about one-fifth the video bitrate found on a typical Blu-ray Disc.

My simple and special ratecontrol systems attempt to produce the highest possible video quality near a target bitrate using a constant ratefactor (CRF) to specify quality. A CRF is represented by a number from 0 to 51 with lower values indicating higher quality. The special value of 0 is for lossless output.

Unfortunately, the output bitrate is extremely unpredictable when using the default CRF-based system in x264 or x265. Typically, people pick a middle-level CRF value as their quality target and just hope for the best. This is what most of the presets built into HandBrake do, choosing a CRF of 20 or 22.

But such a strategy can result in output larger than its input or, worse, output too low in quality to be mistaken for that input.

So I set the target CRF value to 1, the best possible "lossy" quality. Normally this would produce a huge output bitrate but I also reduce the encoder's maximum bitrate to my target, e.g. 6000 Kbps for 1080p output, by manipulating an option called vbv-maxrate.

With this approach, the encoder chooses the lowest CRF value, and therefore the highest quality, which fits below that maximum bitrate ceiling, even if that's usually not a a CRF value of 1.

And this fully describes the behavior of transcode-video when using the --simple option.

However, my special, or default, ratecontrol system also sets a maximum CRF (crf-max) value of 25, raising the minimum quality. This allows vbv-maxrate to become a "soft" ceiling so that the output bitrate can exceed the target when necessary to maintain that quality.

Unfortunately, this internal tug of war can cause the encoder to sometimes generate a few very low quality frames.

As part of the encoding process, a quantizer value (QP) is calculated for each macroblock within a frame of video. A QP is represented by a number from 0 to 69 with lower values indicating higher quality.

So I set a maximum quantizer (qpmax) value of 34, again raising the minimum quality. The occasional bad frame is still there, but it's no longer noticeable because it's now of sufficient quality to blend in with the others.

My average bitrate (ABR) ratecontrol system, selected via the --abr option, is based on the ABR algorithm already within x264 and x265 which targets a specific bitrate.

But I constrain the maximum bitrate (vbv-maxrate) to only 1.5 times that of the target, i.e. to just 9000 Kbps when the target bitrate is 6000 Kbps for 1080p output.

It seems counterintuitive, but constraining the maximum bitrate prevents too much bitrate being wasted on complex or difficult to encode passages at the expense of quality elsewhere. This is because with an average bitrate algorithm, when the peaks get too high then the valleys get too low.

And this manipulation is exactly the same strategy used by streaming services such as Netflix.

My average variable bitrate (AVBR) ratecontrol system, selected via the --avbr option, is also based on the ABR algorithm already within x264 which targets a specific bitrate.

But the maximum bitrate is not constrained like my ABR system.

Instead, the tolerance of missing the average bitrate is raised to the maximum amount, disabling overflow detection completely. This makes the ABR algorithm behave much more like a CRF-based encode, so final bitrates can be 10-15% higher or lower than the target.

And to prevent bitrates from getting too low, the Macroblock-tree ratecontrol system built into x264 is disabled. While this does lower compression efficiency somewhat, it significantly reduces blockiness, color banding and other artifacts.

Unfortunately, these modifications to implement AVBR are not possible when using x265.

No, these warnings are simply a side effect of my special ratecontrol system. The x264 video encoder within HandBrake is just being overly chatty. Ignore it. Nothing is wrong with the output from transcode-video.

My command line tools have the same behavior and scriptable interface across multiple platforms. Developing a GUI application with those requirements is not an investment that I want to make.

Plus, I wouldn't use a GUI for these tasks. And it's a bad idea to develop software that you won't use yourself.

HandBrake has supported High Efficiency Video Coding or H.265 ever since it included the x265 video encoder.

You can try HEVC transcoding now using the --encoder option:

transcode-video --encoder x265 "/path/to/Movie.mkv"

While speed continues to improve, x265 is still considerably slower than the default x264 encoder.

Hardware-based encoders, like those in Intel Quick Sync Video, are often considerably faster than x264 or x265. Some are available in recent versions of HandBrake.

Check the Video Options section from the output of HandBrakeCLI --help to find out if your platform has any of these video encoders available:

You can try hardware-based transcoding now using the --encoder option. On macOS, select the Apple VideoToolbox H.264 encoder this way:

transcode-video --encoder vt_h264 "/path/to/Movie.mkv"

You can also use the --target option with these encoders.

I compare by visual inspection. Always with the video in motion, never frame by frame. It's tedious but after years of practice I know which portions of which videos are problematic and difficult to transcode. And I look at those first.

In addition, I use the query-handbrake-log tool to report on ratefactor, the average P-frame quantizer, to get a relative quality assessment from the x264 encoder.

What I don't use are peak signal-to-noise ratios or a structural similarity index in an attempt to objectively compare quality. Although both metrics are available to the x264 encoder, enabling either of them ironically disables key psychovisual optimizations that improve quality.

I never use the --crop detect function of transcode-video because I don't trust either HandBrakeCLI or ffmpeg to always get it right without supervision. Instead, I use the separate detect-crop tool before transcoding to manually review and apply the best crop values.

I let transcode-video automatically burn any forced subtitles into the output video track when the "forced" flag is enabled in the original.

I never include separate subtitle tracks, but I do add audio commentary tracks.

For a few problematic videos, I have to apply options like --force-rate 23.976 --filter detelecine. But that's rare.

Sunday, February 24, 2019

• Add --audio-format and --keep-ac3-stereo options to transcode-video. Thanks to @samhutchins for the idea and design! Via #254.
  • With the --audio-format option, you can now specify whether AC-3 or AAC is used when surround or stereo output tracks are created.
  • This allows multichannel 5.1 AAC audio output by adding --audio-format surround=aac to your command line. However, you may want to pair that with --audio-width main=surround to avoid two AAC tracks of the same input being created.
  • Think of the --keep-ac3-stereo option as a kinder, gentler form of the --prefer-ac3 option.
  • It copies rather than transcodes AC-3 stereo or mono audio tracks even when the current stereo format is AAC, but it doesn't affect surround tracks.
• Deprecate the --prefer-ac3 option in transcode-video and remove its description from the --help output. Also via #254.
  • The option still works for now, but using it issues a warning message.
  • You can get the exact same functionality by adding --audio-width all=surround --audio-format all=ac3 to your command line.
  • However, you might want to add --audio-width all=surround --keep-ac3-stereo instead since you'll get higher quality and slightly smaller output, albeit with some AAC tracks in your output when stereo audio in non-AC-3 format still needs to be transcoded.
• Add a minimal argument to the --fallback-crop option in transcode-video which determines the smallest possible crop values, when using the--crop detect option and argument, by combining results from both HandBrakeCLI and ffmpeg. Thanks to @dkoenig01 for the idea! Via #255.
• Relax validation criteria for HandBrake-generated .log files in query-handbrake-log as workaround for HandBrakeCLI spewing linkage failure warnings on certain Linux platforms. Via #257.

Sunday, February 10, 2019

• Add a --avbr ratecontrol option to transcode-video (via #248) which:
  • Implements an average variable bitrate (AVBR) ratecontrol system focused on maintaining quality at the risk of final bitrates being as much as 10-15% higher or lower than the target.
  • May emit a few VBV underflow warnings at the beginning of a transcode, but nothing like the sustained deluge possible with my special, or default, ratecontrol system.
  • Works only with the x264 and x264_10bit encoders. Sorry, but the settings necessary to implement AVBR are not available with the x265 family of encoders.
• Add my new AVBR ratecontrol system to the "Explanation" section of the "README" document.
• Add an undocumented --raw ratecontrol testing option to transcode-video which implements, by default, an unconstrained ABR system, easily modified with --handbrake-option and/or --encoder-option.
• Add a --mixdown option to transcode-video which sets the mixdown format for all AAC audio tracks, either Dolby Pro Logic II (the default) or stereo. Thanks to @samhutchins for the idea and the patch! Via #245.
• Fix failure in detect-crop on Linux for certain inputs by forcing the text output from ffmpeg into UTF-8 binary format to ensure the correct parsing of that data during crop detection. Via #247.
• List all hardware-based video encoders within the related answer in the "FAQ" section of the "README" document. Thanks to @vr8hub for the idea! Via #251.
• Update all copyright notices to the year 2019.

Saturday, December 15, 2018

• Add an --encoder option to transcode-video so --encoder x265 will work the same as the much longer and harder to type --handbrake-option encoder=x265.
• Add a --simple ratecontrol option to transcode-video (via #211) which:
  • Works like my special, or default, ratecontrol system but won't emit those annoying VBV underflow warnings because it's only constrained by the target bitrate and not also a minimum quality.
  • Signals Hypothetical Reference Decoder (HRD) information in metadata like my average bitrate (ABR) ratecontrol system.
  • Produces output similar in appearance to that from hardware-based encoders but is less prone to color banding.
• Modify transcode-video to not pass the target video bitrate to hardware-based encoders when a CRF value is also specified, e.g. via something like --handbrake-option quality=20. Currently, this is only applicable to encoders such as nvenc_h264, nvenc_h265, vce_h264 and vce_h265.
• Revise both the H.265 video and hardware-based video transcoding answers in the "FAQ" section of the "README" document.
• Update and simplify the "Explanation" section of the "README" document.

Tuesday, December 4, 2018

• Modify transcode-video to pass the target video bitrate to hardware-based encoders available in HandBrake for Windows and Linux as well as HandBrake nightly builds for macOS:
  • Check the output of HandBrakeCLI --help from one of those builds to find out if your platform has any of these video encoders available.
  • The names of these encoders all end with "_h264" (for H.264) or "_h265" (for HEVC).
  • On macOS, adding --handbrake-option encoder=vt_h264 is all that's needed to enable hardware-based H.264 transcoding. Use vt_h265 for HEVC.
  • On Windows and Linux, use qsv_h264 or qsv_h265. Other encoders might be available as well in nightly builds.
  • WARNING: If you request an encoder that is not available, HandBrakeCLI may fail or it may just fallback to a software-based encoder. Check your console output while transcoding to be certain.
  • These hardware-based encoders are far faster than the software-based x264 and x265 encoders while still delivering reasonable quality. Of course, your mileage (and perception) may vary.

Sunday, December 2, 2018

• Fix a bug in transcode-video creating MP3 instead of AAC audio in MKV output on Windows. This was caused by a previous optimization not passing a named AAC audio encoder to HandBrakeCLI, i.e. ca_aac or av_aac. Apparently the default is different on Windows. Go figure. Thanks, @samhutchins! Via #235.
• Add a workaround in transcode-video for HandBrake nightly builds not setting the mixdown of multichannel audio track inputs to Dolby Pro Logic II format at 160 Kbps when the output is AAC stereo. Apparently the new default for that type of input is 5.1 channels at 384 Kbps, which wouldn't play on most Roku or Apple TV devices without re-transcoding or non-standard software. Again, go figure.
• Add a workaround in transcode-video and convert-video for HandBrake nightly builds not copying mono or stereo audio track inputs which are already in AAC format.

Friday, November 9, 2018

• Modify transcode-video to create "sparse" .log files by removing overwritten progress information, often making those files an order of magnitude (i.e. 10x) smaller. Via #213.
• Replace code in transcode-video which used mkvpropedit or mp4track in a post-transcoding step to sanitize audio titles containing commas, with much simpler code leveraging a comma escaping mechanism only available in HandBrakeCLI version 1.0.0 or later.
• Fix bug in transcode-video where the level was not set when using the x264_10bit encoder.
• Remove support the non-existent x265_16bit encoder in transcode-video. This might have been available last year in some development builds of HandBrakeCLI, but it's definitely not in any release.

Sunday, October 21, 2018

• Modify transcode-video to no longer validate --filter option arguments against a fixed list of names. This will prevent annoying failures whenever the HandBrake team adds a new filter.

Monday, June 18, 2018

• Now require HandBrakeCLI version 1.0.0 or later. Not only does this change make for easier testing, but it allows removal of many capability-detection hacks needed to support older versions. My thanks again to all the users who provided positive feedback about this online!
• Relax frame rate control in transcode-video so that the options --rate=30 and --pfr are no longer passed to HandBrakeCLI for most non-DVD videos. This means that the peak frame rate will no longer be limited to 30 FPS, allowing camera-generated videos to retain their original frame rates. However, the old behavior can be restored for those videos by adding --limit-rate 30 to your transcode-video command line.
• Modify transcode-video to no longer pass --encoder-preset=medium to HandBrakeCLI since that's the default behavior anyway. However, adding --preset medium to your transcode-video command line still does so.
• Modify transcode-video to no longer pass a named audio encoder to HandBrakeCLI in order to select AAC, i.e. ca_aac or av_aac, since AAC is the default audio format anyway. However, adding the --aac-encoder option to your transcode-video command line still allows an explicit choice.
• Modify transcode-video to substitute "analyse" for the x264 option called "partitions" when invoked with the --quick or --veryquick options. This is done to better match the archaic internal name used by HandBrake. It has no effect on actual transcoding behavior.
• Add -n as a shortcut alias for the --dry-run option in transcode-video. This is the same shortcut alias used in rsync and make.
• Expand the "Explanation" section of the "README" document to describe both the special, or default, ratecontrol system and the average bitrate (ABR) ratecontrol system, enabled via the --abr option.
• Add clarification to the "README" document that stereo AAC tracks can also include surround audio information in matrix-encoded Dolby Pro Logic II format.
• Fix spelling of "suppress" in the --help output of query-handbrake-log. Thanks, @chrisridd! Via #205.

Saturday, January 27, 2018

• Add support for Dolby Digital Plus audio format, aka Enhanced AC-3, to transcode-video and convert-video with a new --ac3-encoder option for each tool. Also, extend the --ac3-bitrate and --pass-ac3-bitrate options in transcode-video to support higher bitrates, 768 and 1536 Kbps, available to Enhanced AC-3. Via #26.
  • WARNING: Dolby Digital Plus output is currently NOT COMPATIBLE with the MP4 file format when using transcode-video due to a limitation in HandBrakeCLI. This means that adding both --mp4 and --ac3-encoder eac3 to your command line will fail with the error "incompatible encoder 'eac3' for muxer 'av_mp4'."
  • Oddly enough, ffmpeg doesn't have this limitation so you'll be able to use convert-video --ac3-encoder eac3 to convert your MKV files into MP4 format without any problems. Go figure.
• Remove "Can you add support for Enhanced AC-3 audio?" from the "FAQ" section of the "README" document, for obvious reasons. :)
• Add --reverse-double-order option to transcode-video to reverse order of double-width audio output tracks. Thanks, @samhutchins! Via #184.
• Fix a bug in convert-video where the number of audio channels was wrong when tracks had to be transcoded. This was most noticeable for AAC output and appears due to a change in the behavior of ffmpeg.
• Append .inspect to all Hash objects used as Console.debug arguments. Apparently a change in the way Ruby works was preventing these objects from being printed, although I'm unsure about the specific version of Ruby in which this occurred.
• Remove superfluous quotes in the --help output of transcode-video.
• Remove the deprecated --cvbr and --vbr options in transcode-video and --player option in detect-crop.
• Revise my usage in the "FAQ" section of the "README" document since I no longer choose the default settings with transcode-video.
• Re-order a few misplaced lines in the "History" section of the "README" document.
• Update all copyright notices to the year 2018.

Saturday, December 2, 2017

• Improve the average bitrate (ABR) ratecontrol system provided by the --abr option in transcode-video. Via #179.
  • Implement it with a maximum bitrate constraint to raise its overal quality level and guarantee that it will not generate any VBV underflow warnings like the default ratecontrol system.
  • Signal Hypothetical Reference Decoder (HRD) information, meaning that the VBV maximum bitrate value is added as metadata to the output video, something you should not do when using the default ratecontrol system.
  • Move it from the "Advanced" to the "Quality" section in the --help output and describe its quality output as "different" rather than "lower" compared to the default ratecontrol system.
  • Also remove the no-longer valid characterization of ABR in the "Explanation" section of the "README" document.
• Deprecate the poorly named --cvbr and --vbr options in transcode-video and remove them from the --help output.
  • The ratecontrol system implemented by the --cvbr option was always experimental. After much testing, it was found to be noticeably lower in quality compared to the default and to the new ABR implementation.
  • The ratecontrol system implemented by the --vbr option was only ever intended for comparison testing. And probably used only by myself.
• Modify transcode-video to no longer re-calculate vbv-bufsize based on any user input value for vbv-maxrate. Instead, always calculate both vbv-maxrate and vbv-bufsize based on the target video bitrate.
• Deprecate the --player option in detect-crop and remove it from the --help output.
• Fix failure of subtitle detection for HandBrake nightly builds. Language detection for subtitles in disc image directory input and individual closed caption tracks may still be wrong but will not be fixed at this time. Via #172.
• Mention Nick Wronski's nifty batch-processing wrapper for transcode-video in the the "README" document. Thanks, @JMoVS! Via #180.

Sunday, September 10, 2017

• Force text output from mp4track into UTF-8 binary format to ensure correct parsing of that data. Thanks, @DavidNielsen! Via #152.

Sunday, May 14, 2017

• HandBrakeCLI versions 1.0 and later changed the default frame rate mode from "constant" to "peak-limited" when a rate is specified. This new behavior in HandBrakeCLI requires two significant changes in transcode-video:
  • Fix a bug where the --force-rate option failed to force a constant frame rate. This bug made it behave essentially the same at the --limit-rate option.
  • Fix a bug where a constant frame rate was not forced for inputs containing MPEG-2 video. This bug affected the transcoding of all DVDs but very few Blu-ray Discs. The good news is that this bug probably didn't cause visual problems since the new default peak-limited implementation in HandBrakeCLI versions 1.0 and later worked like a constant frame rate most of the time.
• Modify convert-video to use binary file mode when reading and writing console and log output from ffmpeg. This eliminates redundant information and "console spew" on Windows by suppressing the EOL <-> CRLF conversion. Thanks, @samhutchins! Via #147.
• Also modify transcode-video and convert-video to use binary file mode when processing console I/O from mkvpropedit and mp4track to eliminate that same "console spew" on Windows.
• Modify detect-crop to escape preview commands for cmd.exe and PowerShell on Windows in a manner that's still compatible with Bourne and Z shells. Also mention in the "Using detect-crop" section of the "README" document that path names within the sample commands are not escaped properly when using cmd.exe or PowerShell on Windows and that bash.exe can be used as a workaround. Via #146.
• Modify transcode-video to accept x264_10bit, x265_10bit, x265_12bit and x265_16bit as supported encoders while also adjusting the encoder profile for these variants. Via #143.
• Modify transcode-video to no longer set the x264 encoder level if a frame rate has been requested higher than 30 FPS. Via #141.

Monday, April 3, 2017

• Fix failure of version detection for recent HandBrake nightly builds. Thanks, @kvanh! Via #139.
• Modify detect-crop to escape preview commands for Z shells. Thanks, @jjathman! Via #138.

Wednesday, February 22, 2017

• Modify transcode-video to use binary file mode when reading and writing console and log output from HandBrakeCLI. This eliminates redundant information and "console spew" on Windows by suppressing the EOL <-> CRLF conversion. Thanks, @samhutchins! Via #130.

Thursday, February 16, 2017

• Remove all dependencies on mplayer, via #120 and #123:
  • Modify detect-crop and transcode-video to use ffmpeg for crop detection instead of mplayer.
  • Modify detect-crop to use mpv, a free cross-platform media player, for optional crop preview instead of mplayer.
  • Add a --player option to detect-crop so mplayer can still be used for crop preview commands. Warning: this feature will be deprecated soon.
• Update the "README" document to:
  • Remove any mention of mplayer and list mpv as an optional package.
  • Fix typo in version 0.16.0 release information. Thanks, @samhutchins!

Friday, January 20, 2017

• Add a --cvbr option to transcode-video. This is essentially the same as the experimental option of the same name which was removed on February 25, 2016, but now it doesn't have a bitrate argument. It enables a simple constrained variable bitrate (CVBR) ratecontrol system, less constrained than the default, producing a more predictable output size while avoiding VBV underflow warnings. Use it with --target big for the best results.
• Modify the --abr option in transcode-video to no longer use a bitrate argument. Instead, it relies on the --target option to control bitrate, just like the default ratecontrol system and the new --cvbr option. So, passing a bitrate argument is now an error. But you should consider using --cvbr instead of --abr anyway since the former is almost always higher quality.
• Remove the deprecated --no-constrain option from detect-crop and the --no-constrain-crop option from transcode-video.
• Modify convert-video to allow HEVC format video along with H.264.
• Update the "README" document to:
  • Revise and simplify the Windows installation instructions to point users at the fine work by @samhutchins and @JMoVS on documenting their two methods. Via #115.
  • Revise the "Using transcode-video" section to correct out-of-date performance data about the --quick option.
  • Revise the H.265 answer in the "FAQ" section with up-to-date information about the x265 video encoder. Via #118.

Sunday, January 15, 2017

• Modify convert-video, via #114, to:
  • Add support for text-based and DVD-style image-based subtitles. Please note that Blu-ray Disc-style image-based subtitles are not supported due to MP4 format restrictions.
  • Add a --no-double option which no longer assumes input files might contain two main audio tracks whose order needs to be swapped, or that a "missing" stereo AAC audio track needs to be added to MP4 output.
  • Change the algoritm deciding when a "missing" stereo AAC audio track is added. Previously that only happened when the first track of the input MKV file was in surround format and there were no other audio tracks. Now it won't matter how many audio tracks are in the input.
  • Use ffmpeg and mkvpropedit for conversion to MKV format instead of just mkvmerge which could not convert subtitle formats.
  • Remove the dependency on mkvmerge and add a dependency on mkvpropedit.
  • No longer pass the -strict experimental arguments to ffmpeg when using the built-in, native AAC encoder.
• Fix a bug preventing the detection of whether an audio track had the "default" flag set when parsing scan output from HandBrakeCLI versions 1.0.0 and later. This was caused by the integration of Libav version 12.0 in HandBrake on December 17, 2016.
• Fix a long-standing bug preventing the detection of all subtitles and disambiguation with chapter information in MP4 files when parsing scan output from mp4track.
• Remove support for the Freeware Advanced Audio Coder (FAAC) from the "FFmpeg" module since it's no longer included with ffmpeg.
• Remove the "mkvmerge.rb" source file and any references to the "MKVmerge" module since convert-video no longer needs it.
• Update the "README" document to:
  • Remove mkvmerge from the "Requirements" section.
  • Clarify subtitle support in the "Using convert-video" section.

Wednesday, January 4, 2017

• Add a --prefer-ac3 option to transcode-video. This prefers Dolby Digital AC-3 over AAC format when encoding or copying audio, even when the original track channel layout is stereo or mono. It also sets the audio output "width" for all tracks to surround. Via #112.
• Fix a bug in the parsing of audio and subtitle track names that was introduced by the integration of Libav version 12.0 in HandBrake on December 17, 2016, affecting HandBrakeCLI versions 1.0.0 and later. This caused transcode-video to substitute any commas with underscores in added audio track names when used with those versions of HandBrakeCLI.

Monday, January 2, 2017

• Modify the --quick option in transcode-video to remove the x264 mixed-refs=0 setting because it's unnecessary when the ref=1 setting is also applied. Via #108.
• Add a --veryquick option to transcode-video for encoding 90-125% faster than the default setting with little easily perceptible loss in video quality. Unlike --quick, its output size is larger than the default. Via #108.
• Remove the deprecated --small and --small-video options from transcode-video.
• Update all copyright notices to the year 2017.
• Update the "README" document to:
  • Revise the installation instructions to reflect that HandBrakeCLI has been removed from Homebrew Cask (thanks to @vitorgalvao) and is now part of Homebrew Core (thanks to @JMoVS). Via #106 from @vitorgalvao.
  • Revise the version of HandBrakeCLI required for HEVC transcoding to 1.0.0 or later in the "FAQ" section.
  • Clarify Enhanced AC-3 audio support in the "FAQ" section.

Tuesday, December 6, 2016

• Increase the speed and quality of the --quick option. Encoding is now 70-80% faster than the default setting with no easily perceptible loss in video quality. The improvement is so good that I no longer recommend using x264 presets to speed things up. Via #104.
• Update the "README" document to:
  • Revise the "Understanding the x264 preset system" section to suggest using --quick or --target big instead of faster or slower presets.
  • Add Docker virtualization software installation instructions. Via #98 from @ntodd.

Sunday, November 6, 2016

• Modify transcode-video to use HandBrake's new "auto-anamorphic" API, if available, instead of "strict-anamorphic". The HandBrake team removed the "strict-anamorphic" API on October 31, 2016, breaking transcode-video when it's used with the latest nightly builds. Via #67 from @iokui.
• Add "auto-anamorphic" and "non-anamorphic" to the list of HandBrake APIs disabled when the --pixel-aspect option is used with transcode-video.
• Re-enable the x264 video encoder when the --quick option is used with transcode-video.

Friday, November 4, 2016

• Modify transcode-video to enable the --quick option only for the x264 video encoder and enable my special ratecontrol system only for the x264 and x265 encoders.
• Update the "README" document to:
  • Revise the H.265 answer in the "FAQ" section to show how you can try experimental HEVC transcoding now.
  • Use new canonical "macOS" name.
  • Add "Explanation" section describing how my special ratecontrol system works.

Friday, October 14, 2016

• Revise the ratecontrol system and default target video bitrates in transcode-video so that output is smaller and transcoding is faster. Via #90.
  • Increase the value of vbv-bufsize to be twice that of vbv-maxrate, the target. This is much more likely to produce an output video bitrate nearer to that target.
  • Lower the targets to accomodate this new accuracy and avoid wasting bitrate and time on unneeded quality.
• Deprecate the --small and --small-video options in transcode-video.
• Add a variation of the --target option with big and small arguments to transcode-video. The small macro provides output similar to, but still smaller than, the old --small-video option. The big macro provides output even larger than the old ratecontrol system and targets.
• Remove unnecessary boundary checking of the target video bitrate in transcode-video.
• Modify transcode-video so adding --handbrake-option encoder=x265 is all that is needed to enable experimental HEVC transcoding. Use this only with HandBrakeCLI nightly builds from September 29, 2016, or later.
• Update the "README" document to:
  • Revise the default target video bitrates.
  • Remove all references to the --small option since it's now deprecated.
  • Add the Windows Subsystem for Linux as a possible installation platform. Via #89 from @JMoVS.
  • Replace visible HTML comments with zero-width spaces.
  • Tweak the description of how I use transcode-video. Yes, again.

Monday, September 26, 2016

• Add queue-import-file and anything starting with preset to the list of unsupported HandBrakeCLI options.
• Back out a change from version 0.3.1 to optimize setting the encoder level to behave more like past versions. This made no actual difference in the output video, only the .log file.
• Update the "README" document to:
  • Clarify tradeoffs when using the x264 preset system.
  • Revise the status of H.265 and Enhanced AC-3 support.
  • Tweak the description of how I use transcode-video. Again.

Thursday, September 15, 2016

• Change the behavior of detect-crop and the --crop detect function of transcode-video to no longer constrain the crop by default. Add a --constrain option to detect-crop and a --constrain-crop option to transcode-video to restore the old behavior. Also, deprecate the --no-constrain option of detect-crop and the --no-constrain-crop option of transcode-video since both are no longer necessary. Via #81.
• Update the "README" document to:
  • Revise multiple sections about the changes to cropping behavior.
  • Revise the description of the --small option in multiple sections.
  • Revise how I use transcode-video in the "FAQ" section.
• Add support for the comb-detect, hqdn3d and pad filters to transcode-video.
• Fix a bug in transcode-video where the --filter option failed when nlmeans-tune was used as a argument. This was due to a regular expression only allowing lowercase alpha characters and not hyphens.
• Update the default AC-3 audio and pass-through bitrates in the --help output of transcode-video to 640 Kbps, matching the behavior of the code since version 0.5.0.

Friday, May 6, 2016

• Add resolution-specific qualifiers to the --target option in transcode-video. This allows different video bitrate targets for inputs with different resolutions. For example, you can use --target 1080p=6500 alone to change the target for Blu-ray Discs and not DVDs. Or you could combine that with --target 480p=2500 to affect both resolutions. Via #68 from @turley.
• Fix a bug in transcode-video where video bitrate targets were not reset when the --small or --small-video options followed the --target option on the command line.
• Fix a bug where query-handbrake-log would fail for time or speed on macOS or Linux when parsing .log files created on Windows. This was due to a regular expression not expecting a carriage return (CR) before a line feed (LF), i.e. a Windows-style line ending (CRLF). Via #67 from @lambdan.

Monday, May 2, 2016

• Revise the syntax and behavior of the --main-audio, --add-audio and --audio-width options in transcode-video:
  • Allow selecting the main audio output track by finding the first input track in a specific language. For example, --main-audio spa can now use a language code to select the first Spanish track. Previously, only track numbers were allowed as main audio selection arguments. Via #8 from @JMoVS.
  • Allow assignment of an optional name to the main audio track when using a language code. For example, --main-audio spa="Other Dialogue" sets the track name in the same manner as using a track number.
  • Restrict the default main audio track to the first track, i.e. track number 1, if the --main-audio option is not used. Previously, the default main audio track could be the first track selected by the --add-audio option when a language code argument was used. This was a hack because, at that time, the --main-audio option itself couldn't select by language.
  • No longer require or even allow language= to prefix a language code argument when using the --add-audio option. For example, use --add-audio fra to add all the French language tracks. This is much easier to type.
  • Add argument shortcuts to select the main track or other non-main tracks when using the --audio-width option. Previously, tracks were selected only by track number or all at once. The main shortcut is useful when the main audio track number is unknown because it was selected using a language code. The other shortcut is useful when all would also modify the main audio track.
• Revise the syntax of the --add-subtitle option in transcode-video to match the change to the --add-audio option which no longer requires or even allows language= to prefix a language code argument.
• Add a --tabular option to query-handbrake-log in order to better format its output report for later import into a spreadsheet application. This uses a tab character instead of a single space as the field delimiter and suppresses the fps and kbps labels. Via #64.
• Fix a bug where query-handbrake-log time reported the wrong result when parsing .log files from output using a forced frame rate. It's possible this was a regression due to a change in HandBrake.
• Remove a stray "TODO" comment line in query-handbrake-log.
• Update the "README" document to:
  • Revise the "Understanding audio" section to reflect new syntax and behavior in transcode-video.
  • Add links to the "History" section for release numbers, pull requests, issues and contributors.
  • Correct the release date for version 0.4.0 in the "History" section.
  • Insert a missing "Via" and period in the 0.8.1 release information.

Thursday, April 28, 2016

• Fix a bug where query-handbrake-log reported the wrong time or speed when parsing .log files containing output from HandBrake subtitle scan mode, i.e. when using --burn-subtitle scan or --force-subtitle scan from transcode-video. Via #46 from @martinpickett.
• Fix a bug where query-handbrake-log ratefactor failed if the number it was searching for was less than 10. This was due to HandBrake unexpectedly inserting a space before that number. Honestly, I doubt this ever happend before the new ratecontrol system debuted in 0.6.0. That's how good the new ratecontrol system is. Via #61 from @bmhayward.

Sunday, April 24, 2016

• Add a --no-constrain-crop option to transcode-video. This changes the behavior of --crop detect to mimic the --no-constrain option in the detect-crop tool.
• Add a --fallback-crop option to transcode-video. This selects fallback crop values, from HandBrake, MPlayer or no crop at all, if --crop detect fails. This makes the new --no-constrain-crop option more useful since failure is more likely without constraints. Via #56 from @cameronks.
• Add a --aac-encoder option to transcode-video. This gives Windows and Linux users access to the Fraunhofer FDK AAC encoder if it's compiled into their version of HandBrakeCLI. Via #35 from @cnrd.
• Allow a colon (":") instead of a just period (".") to separate the two numerical components of a stream identifier when parsing scan output from HandBrakeCLI. This ensures compatibility with different versions of libavcodec and should fix several mysterious bugs on some Linux configurations. Via #30 and #41 from @dgibbs64.
• Maintain 480p video bitrate targets in transcode-video when scaling down to 480p using --max-width 854 --max-height 480. Via #58 from @mschout.
• Remove the deprecated --old-behavior option in transcode-video.
• Clarify the purpose of --abr and --vbr in the --help output of transcode-video.
• Update the "README" document to:
  • Add "FAQ" section. Via #26 from @reiesu and #59 from @dgibbs64.
  • Add this "History" section.
  • Spell "rate control" as one word, like a real transcoding geek.
  • Insert a missing "you" in the first paragraph of the "Installation" section.
  • Mention and link to Linuxbrew in the "Requirements" section.
  • Describe the default ratecontrol system as a "modified constrained variable bitrate (CVBR) mode."
  • Add example output when HandBrake and MPlayer disagree to the "Using detect-crop" section. Via #18 from @alanwsmith.
  • Update the status of DTS-HD decoding for HandBrake and MakeMKV in the "Why convert lossless audio?" section.

Thursday, April 7, 2016

• Once again, lower the video bitrate targets for 480p and 720p output in transcode-video. Note that 1080p and 2160p targets still remain unchanged. Via #55.
• Update the "README" document to:
  • Reflect changes to the 480p and 720p video bitrate targets.
  • Revise description of and recommendation for the --quick option.
  • Revise warnings about using slower x264 presets.
• Add a --target option to transcode-video allowing explicit control of the video bitrate target.
• Deprecate the --old-behavior option in transcode-video.
• Remove the deprecated --big option in transcode-video.
• Separate --small and --small-video in the --help output of transcode-video.

Sunday, April 3, 2016

• Revise the default ratecontrol system and video bitrate targets in transcode-video:
  • Raise the quality target by lowering the constant ratefactor (CRF) from 16 to 1, the lowest lossy CRF value available with the x264 video encoder. This significantly improves video quality but also raises bitrates much closer to the targets, thereby increasing output file sizes for some inputs.
  • Raise the quality limit by setting qpmax, the x264 quantizer maximum, to 34. This prevents x264 from occasionally generating a single, but still noticeable, very low quality frame because the CRF value is set so low.
  • Lower the video bitrate targets for 480p and 720p output to keep bitrates and file sizes closer to that produced by the old ratecontrol system. Note that 1080p and 2160p targets remain unchanged.
  • Add an --old-behavior option to restore the old ratecontrol system and video bitrate targets for users not yet wanting to change over. This option is only temporary and will soon be deprecated and then removed.
  • Update the "README" document to reflect changes to the 480p and 720p video bitrate targets.
• Remove an obsolete brew install caskroom/cask/brew-cask line from the "README" document. Via #54 from @timsutton.

Thursday, February 25, 2016

• Don't fail if the ffmpeg version string can't be parsed. Via #43 from @rementis, @Lambdafive and @kford.
• Remove the deprecated --cvbr option in transcode-video.

Thursday, January 14, 2016

• Raise the default video bitrate targets and AC-3 audio bitrate limits in transcode-video:
  • Deprecate the --big option since its behavior is now the default. An informal survey via Twitter and Facebook showed that about 90% of users (including myself) responding were always using the --big option anyway to get higher quality.
  • Add a --small option to restore the old video bitrate targets and AC-3 audio bitrate limits.
  • Add a --small-video option to restore only the old video bitrate targets. Via Facebook from @DaveHamilton.
  • Update the "README" document to reflect all these changes.
• Move --abr and --vbr to the advanced options section in the --help output of transcode-video.
• Deprecate the experimental --cvbr option in transcode-video.

Monday, January 11, 2016

• Add a --cvbr option to transcode-video. This implements a very experimental variation of the default ratecontrol system with a target bitrate as its single argument. Use it for evaluation purposes only.

Friday, January 8, 2016

• Fix compatibility with development/nightly builds of HandBrakeCL in transcode-video:
  • Always force the x264 medium preset to override the new veryfast default value. Via #36 from @cnrd.
  • Explicitly set the encoder profile to high to override the new main default value.
  • Explicitly (and dynamically) set the encoder level to override the new 4.0 default value.
• Fix a stupid regression from version 0.2.8 caused by a typo in the patch for the SubRip-format text file offset fix to transcode-video. Via #37 from @bpharriss.
• Be more lenient about --encoder-option arguments in transcode-video so 8x8dct is allowed.
• Always print the HandBrakeCLI version string to diagnostic output even if it can't be parsed.

Tuesday, January 5, 2016

• Add a --abr option to transcode-video. This implements a modified average bitrate (ABR) ratecontrol system with a target bitrate as its single argument. It produces a much more predictable output size but lower quality than the default ratecontrol system. It can sometimes be handy but use it with caution.
• Add a --vbr option to transcode-video. This implements a true VBR ratecontrol system with a constant ratefactor as its single argument, much like HandBrake's default behavior when using its --quality option. It's useful mostly for comparison testing against the default ratecontrol system.
• Update all copyright notices to the year 2016.

Tuesday, January 5, 2016

• Prevent the --bind-srt-language option in transcode-video from also setting the SubRip-format text file offset to the same value. This was a stupid copy and paste error since the initial project version. Via #25 from @arikalish.
• Don't fail if the HandBrakeCLI version string can't be parsed. Via #29 from @paulbailey.
• Don't fail if the mp4track version string can't be parsed. Via #27 from @dgibbs64.
• Add a missing preposition to the last bullet point of the "Why MakeMKV?" section in the "README" document. Via #32 from @eventualbuddha.

Tuesday, July 7, 2015

• Apply the --subtitle-forced option when scanning subtitles in transcode-video. Via #20 from @rhapsodians.

Wednesday, May 20, 2015

• Prevent the user's file format choice from corrupting the output path in transcode-video and convert-video. Via #5 from @arikalish.

Sunday, May 17, 2015

• Simplify the calculation of vbv-bufsize in transcode-video.

Friday, May 15, 2015

• Prevent an undefined method error if HandBrakeCLI removes tracks during scan. Via #15 from @blackoctopus.

Tuesday, May 12, 2015

• No longer fail on invalid audio and subtitle track information when parsing scan output from HandBrakeCLI. Via #11 from @eltito51 and #13 from @tchjunky.

Monday, May 11, 2015

• Ensure the AC-3 passthru bitrate in transcode-video is never below the AC-3 encoding bitrate.

Sunday, May 10, 2015

• Fix the --main-audio option in transcode-video by ensuring the resolve_main_audio method actually returns a result. Via #9 from @JMoVS.

Saturday, May 9, 2015

• Rewrite the automatic frame rate and deinterlace logic in transcode-video to match the behavior of the old transcode-video.sh script on which the tool is based.
• Clarify in --help output that transcode-video audio copy policies only apply to main and explicitly added audio tracks.
• Ignore the sometimes missing patch version when checking MPlayer.
• Mention in the "README" document that custom track names and external subtitle file names are allowed to contain commas.

Friday, May 8, 2015

• Fix a stupid regression from version 0.1.2 caused by the line endings fix on Windows. Via #7 from @brandonedling.

Friday, May 8, 2015

• Check the extra version number for MPlayer to accept all builds. Via #6 from @CallumKerrEdwards.

Thursday, May 7, 2015

• Fix handling of DOS-style line endings when parsing scan output from HandBrakeCLI on Windows. Via #4 from @CallumKerrEdwards and @commandtab.
• Disable automatic subtitle burning in transcode-video when input is MP4 format.
• Clarify usage of --copy-audio option in the "README" document. Via #5 from @arikalish.
• Fix some section links in the "README" document. Via #3 from @vitorgalvao.

Wednesday, May 6, 2015

• Add a workaround in the Media class initialize method for no required keyword arguments in Ruby 2.0. Via #1 from @cadonau and #2 from @CallumKerrEdwards.

Tuesday, May 5, 2015

• Initial project version.

The best way to send feedback is mentioning me, @donmelton, on Twitter. You can also file bugs or ask questions in a longer form by creating a new issue on GitHub. I always try to respond quickly but sometimes it may take as long as 24 hours.

A big "thank you" to the developers of HandBrake and the other tools used by this package. So much wow.

Thanks to Rene Ritchie for letting me continue to babble on about transcoding in his podcasts.

Thanks to Joyce Melton, my sister, for help editing this "README" document.

Many thanks to Jordan Breeding and numerous others online for their positive feedback, bug reports and useful suggestions.

Video Transcoding is copyright Don Melton and available under a MIT license.