clementfarabet / lua---ffmpeg Goto Github PK

local ffmpeg_cmd = (FFMPEG .. ' -r ' .. self.fps)
==>
local ffmpeg_cmd = ('ffmpeg -r ' .. self.fps)

The rockspec for this package in https://github.com/torch/rocks points to the tag 1.0-0 and the fix for the missing sys functions in the last commit is not included there. The package won't work correctly if installed with luarocks.

If I call this as vid = ffmpeg.Video('somevideo.mp4') and then check the contents of vid with print(vid) it just shows "ffmpeg.Video", no "{...}" and I cannot seem to index into it. What is the format/type returned?

I am not sure if this is an issue or my misusage but I am going to report it anyways.

The following usage loads a video, but at the end of the constructor vid.n_channels is set to 0 by vid:clear()

require 'ffmpeg'

vid = ffmpeg.Video('office20150910.mp4')
print(vid.n_channels) --- prints 0

due to the fact vid.n_channels=0, the following functions won't work.

print(vid:forward()) -- returns {}
vid:save('test.avi')  -- generate empty test.avi

but if I manually set n_channels back to 1, everything work as expected.

vid = ffmpeg.Video('office20150910.mp4')
vid.n_channels = 1
print(#(vid:forward()))  -- this one return a 3d tensor of the frame.

The current API forces you to set both the fps and the video resolution. It would be good to be able to query the video fps/resolution and/or be able to use the native resolution.

Hello,

It seems that after a few calls on ffmpeg.Video with the load parameter set to true, the memory used by the previous video is not freed even though the same object is used to recieve the return value of ffmpeg.Video.

Regards

EDIT : The memory leak is confirmed. Its due to image:load. Lua gc cant free tensors created by image:load...
https://groups.google.com/forum/#!topic/torch7/mWcQjP2WEVQ

FFMPEG bindings for Lua don't work. I have reproduced the error below.

ffmpeg works through command line. But not through Lua.

th> require 'ffmpeg'
{
  Video : {...}
}
                                                                      [0.0162s]
th> ffmpeg.Video()
WARNIN  
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Video

loads a video into a table of tensors:
 + relies on ffpmeg, which must be installed
 + creates a local scratch/ to store temp frames on disk

> usage:
Video{
    [path = string]                     -- path to video
    [width = number]                    -- width  [default = 320]
    [height = number]                   -- height  [default = 240]
    [zoom = number]                     -- zoom factor  [default = 1]
    [fps = number]                      -- frames per second  [default = 10]
    [length = number]                   -- length, in seconds  [default = 10]
    [seek = number]                     -- seek to pos. in seconds  [default = 0]
    [channel = number]                  -- video channel  [default = 0]
    [load = boolean]                    -- loads frames after conversion  [default = true]
    [delete = boolean]                  -- clears (rm) frames after load  [default = true]
    [encoding = string]                 -- format of dumped frames  [default = png]
    [tensor = torch.Tensor]             -- provide a packed tensor (NxCxHxW or NxHxW), that bypasses path
    [destFolder = string]               -- destination folder  [default = scratch]
    [silent = boolean]                  -- suppress output  [default = false]
}

Video{width=number, path=string}
Video(string, ...)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
/home/utkarsha/torch/install/share/lua/5.1/xlua/init.lua:320: error
stack traceback:
    [C]: in function 'error'
    /home/utkarsha/torch/install/share/lua/5.1/xlua/init.lua:320: in function 'error'
    /home/utkarsha/torch/install/share/lua/5.1/xlua/init.lua:543: in function 'unpack'
    /home/utkarsha/torch/install/share/lua/5.1/xlua/init.lua:603: in function 'unpack_class'
    /home/utkarsha/torch/install/share/lua/5.1/ffmpeg/init.lua:64: in function '__init'
    /home/utkarsha/torch/install/share/lua/5.1/torch/init.lua:91: in function </home/utkarsha/torch/install/share/lua/5.1/torch/init.lua:87>
    [C]: in function 'Video'
    [string "_RESULT={ffmpeg.Video()}"]:1: in main chunk
    [C]: in function 'xpcall'
    /home/utkarsha/torch/install/share/lua/5.1/trepl/init.lua:650: in function 'repl'
    ...rsha/torch/install/lib/luarocks/rocks/trepl/scm-1/bin/th:199: in main chunk
    [C]: at 0x00406670  

t7> ffmpeg.Video()
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Video

loads a video into a table of tensors:
 + relies on ffpmeg, which must be installed
 + creates a local scratch/ to store temp frames on disk

> usage:
Video{
    [path = string]                     -- path to video
    [width = number]                    -- width  [default = 320]
    [height = number]                   -- height  [default = 240]
    [fps = number]                      -- frames per second  [default = 10]
    [length = number]                   -- length, in seconds  [default = 10]
    [seek = number]                     -- seek to pos. in seconds  [default = 0]
    [channel = number]                  -- video channel  [default = 0]
    [load = boolean]                    -- loads frames after conversion  [default = true]
    [delete = boolean]                  -- clears (rm) frames after load  [default = true]
    [encoding = string]                 -- format of dumped frames  [default = png]
    [tensor = torch.Tensor]             -- provide a packed tensor (NxCxHxW or NxHxW), that bypasses path
}

Video{width=number, path=string}
Video(string, ...)
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

If the fps = 10 and length = 10s, therefore there could be only 100 photograms?
How does this work?

Thanks

Thank you for the good tools, it's very helpful to handle video files.
There is one little thing that makes me annoying.
When I use ffmpeg, there are so many log messages.
I want to reduce log messages. I saw the code and found that if silent=true then it would work. But I don't know how to set silent=true. Can you help me with that?

Hi,

I am getting the following error when loading the video. I am using CentOS.

Have tried installing image module but the issue persists.

/usr/local/torch/install/share/lua/5.1/xlua/init.lua:360: module 'libpng' not found:
no field package.preload['libpng']
no file '/root/.luarocks/share/lua/5.1/libpng.lua'
no file '/root/.luarocks/share/lua/5.1/libpng/init.lua'
no file '/usr/local/torch/install/share/lua/5.1/libpng.lua'
no file '/usr/local/torch/install/share/lua/5.1/libpng/init.lua'
no file './libpng.lua'
no file '/usr/local/torch/install/share/luajit-2.1.0-beta1/libpng.lua'
no file '/usr/local/share/lua/5.1/libpng.lua'
no file '/usr/local/share/lua/5.1/libpng/init.lua'
no file '/usr/local/torch/install/lib/libpng.so'
no file '/root/.luarocks/lib/lua/5.1/libpng.so'
no file '/usr/local/torch/install/lib/lua/5.1/libpng.so'
no file './libpng.so'
no file '/usr/local/lib/lua/5.1/libpng.so'
no file '/usr/local/lib/lua/5.1/loadall.so'
warning: could not be loaded (is it installed?)