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• VBR header created for CBR encoded mp3 when using ffmpeg with lame codec ?

  7 novembre 2012, par user784637

  When I run this command to perform a lossy-to-lossy transcode from a youtube video (audio encoded in either aac or vorbis) to mp3 at constant bit rate (cbr)..

  ffmpeg -y -i input.vid -vn -acodec libmp3lame -ab 128K -- output.mp3

  the resulting file has a Xing header (intended to be associated with variable bit rate, vbr, files) instead of CBR header. I do not know if this is an issue with ffmpeg or with the lame codec. How do I force a CBR header to be written instead of the Xing Header?

  The reason I ask is because on some old software, the song loops perpetually and on older firmware of some mp3 players the song will cause the player to crash due to the header discrepancy.

  If it's not possible to force a CBR header to written, are there any linux command line tools that can change this header? The only linux cli program I found was mp3val, however when I run the -f option it reports the file is just fine and dandy.

• libavcodec decode AVFrames to FIFO buffer

  6 novembre 2012, par user1175197

  My aim is to decode multiple frames of a video file, accumulate the decoded frames into a FIFO buffer and read them later on. I decode the packet to my AVFRame mFrame:

  avcodec_decode_video2(mCodecContext,mFrame,&frameFinished,&mPacket);

  Normally I can just copy the YUV frames from the mFrame->data[n][0] to my FIFO buffer but I am just trying to reduce the memcpy 's as much as possible. So instead of copying mFrame->data[n][0] I just want to store the mFrame (which is much smaller than the frames it points to) in the buffer and when it comes to reading I can just fetch it and reach the data.

  I tried to do this but it did not work. The AVFrames are fetched from the buffer but when you show them on the screen the video is like frozen. You may think that I am using the same mFrame and overwriting it each time I decode a packet but I am not. I am creating a new AVFrame* each time in the decode loop.

  Is this problem related to how avcodec works? Any ideas?

  Thanks mike

• Upload video that filmed by iPhone [closed]

  6 novembre 2012, par user1801625

  Possible Duplicate:
  Rotating videos with FFmpeg

  When somebody film a video and upload to my website It appears in the horizontally How can I make this vertical? using ffmpeg?

  and its only heppend if he film its horizontally.

  Sorry for my English

• Capture screen from Tegra 2 GPU with ffmpeg

  6 novembre 2012, par Erb

  The Tegra 2/3 SOC does not provide access to framebuffer using the usual /dev/graphics/fb0 dev. I know that it is still possible to capture the framebuffer using the gralloc method and actually some applications already use this method.

  Is there a way to make FFMpeg use the gralloc method to do the capture? Alternatively, Is there a way to emulate /dev/fb0 for Tegra SOC ?

• Generate 3gp video file using my image library

  6 novembre 2012, par Turgay Gençer

  I need to generate 3gp video file using images.

  Fore example, I have 3 pictures and I want to put slide time for each pictures and generate 3gp.

  1. Picture = 2 second,
  2. Picture = 3 second,
  3. Picture = 5 second,

  and my 3gp is include 3 pictures.

  İs that the possible to generate 3gp using my pictures library ?

  I m writing in C# .

  Thanks.