Newest 'ffmpeg' Questions - Stack Overflow

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• How can i capture video from a usb camera using c program

  13 août 2013, par Asif

  I'm trying to write an API to record a video from my usb camera.I tried using v4l2,ffmpeg but i can only capture images using those codes.I googled out full to find a v4l2 sample code from the link http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html i'm not able to run.if i run the code it just displays junk values it the screen then i have to break it manually.if i run it i'm not able to record any video.Can any one suggest me a sample code to record a video from an usb camera in c program. Thank you...

• Convert a Video FIle [on hold]

  13 août 2013, par user1767288

  Can anyone help me with Converting a video file from I420 to nv12 actually I am new to perl scripting and I tried every way I can, I can see some one suggesting the use of ffmpeg, I went through the documentation but I am not successful with that. I broke down the above question into pseudo code but I am not able to move forward as I am new to perl scripting.

  Can anyone help me

• ffmpeg : silence sepecific parts of an audio track

  12 août 2013, par ExpertNoob

  How can I silence (mute) specific intervals in a multichannel audio file ?

  Can it be done with fade-in / fade-out ?

  I couldn't do it with "aevalsrc", and "volume" doesn't support time specification !

• How to copy audio stream using FFMpeg API ( not a command line tool )

  12 août 2013, par Jindong Jung

  I'm developing some Video Editing Apps on Android.

  the objective of the app is "Editing Videos on Android".

  and...

  I'm just completed making video file using some images. but.. I can't attach audio into the video.

  my method is same as follows.

  1.VideoStream, audio stream creation using AVFormatContext

  2.Movie encoding in video stream was successful

  3.Encode codec open in audio stream was successful

  4.Set sample format to AV_SAMPLE_FMT_FLTP

  5.Sample rate and channel was set same as source audio

  6.Choose appropriate Decoder and read packet

  7.Convert packets using swr_converter, setting same as sample format

  8.Encode converted data

  9.memory deallocation

  10.END!

  ---

  Problem is here:

  Video of finally created video file was normally played. but the Audio wasn't.

  It heared like weird. It have many noises and plays slowly.

  I've googled with many keywords but they only say about "FFmpeg command line usage".

  I wanna make with FFMpeg API. not a Command line tool.

  Please help.

• VLC empty edit issue

  12 août 2013, par user2675209

  We have recorded a live stream. The time stamps are seconds from epoch. We have used FFMPEG for muxing and provided the same time stamps as in live stream. I have two observations:

  1. If initial timestamp is 0. The file plays properly using VLC.
  2. But we require to preserve the timestamps while muliplexing.

  In this case when initial time stamp is non-zero, VLC shows 2 tracks for 1 elst box , It waits for the first track to get over, which is actually an empty edit list with media time=-1.

  Can you suggest any change while multiplexing using FFMPEG to play the file normally. PS: ffplay plays the file properly.

  Thanking in anticipation