Newest 'ffmpeg' Questions - Stack Overflow

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• Reg-Video Rotation Metadata

  16 octobre 2013, par user2882101

  If I use:

  ffmpeg -i in.mov -vf "transpose=1" out.mov

  All mov files are getting rotated, but what I need is to automatically detect just the rotated videos and change orientation for just those videos. Please help.

  How can I automatically detect the rotation or orientation of the video during upload and rotate if needed, so that all mov files play in the correct orientation?

  How can I get that metadata of current degree rotation of my video?

• Remuxing DIVX to MP4 for iDevices

  16 octobre 2013, par Chris Robinson

  Please note, everything I refer to hereafter is using ffmpeg.

  I have a DIVX video which has an mpeg4 codec (MPEG4 Part 2) and an mp3 audio stream as given by ffmpeg -i file.avi. It's my understanding that I should simply be able to remux into an mp4 container for use with iTunes and iDevices by

  ffmpeg -i file.avi -vcodec copy -acodec copy output.mp4
  

  seeing as both codecs are complient with the Mpeg4 Part 14 specification. However I can't import these files into iTunes. I'm assuming this is because the FourCC of the original stream has been set to DIVX.

  Is there an easy way to change this without re-encoding the video stream? I'm looking to remux rather than re-encode to keep losses to a minimum and because I have a massive library of DIVX files that I want to import into iTunes and ffmpeg is easily scriptable for addition of future files.

• Auto detect rotation and rotate video accordingly with java, ffmpeg

  16 octobre 2013, par Lakshmi Priya.K

  Can anyone please help me with this?

  On converting videos to SWF, MOV files are rotated 90 degrees by default. I am using the JAVE Swf Converter and the JAVE Encoder.

  If I use:

  ffmpeg -i in.mov -vf "transpose=1" out.mov
  

  All mov files are getting rotated, but what I need is to automatically detect just the rotated videos and change orientation for just those videos. Please help.

  How can I automatically detect the rotation or orientation of the video during upload and rotate if needed, so that all "mov" files play in the correct orientation?

  Thanks, Lakshmi Priya.K

• Streaming microphone audio to tag with FFmpeg

  16 octobre 2013, par noodleboy347

  I've been working on a nodejs server that streams a live webcam feed and I've been looking for a way to get audio working but I'm completely stumped.

  The video is being streamed onto a canvas element with jsmpeg, and is being streamed with the following command (I'm not sure that this is even successfully streaming audio):

  ffmpeg -s 640x480 -f vfwcap -i video="/dev/video0":audio="Microphone" -f mpeg1video -acodec libmp3lame -b:v 30k -r 24  -b:a 24k -ar 22050 http://website.com:8082
  

  So what I'm wondering is, maybe there's a possible way to stream the audio with the HTML5 audio tag, or maybe even use WebM, just any good solution. What's the best way for streaming live video and audio with nodejs?

• Does MediaCodec truncate incoming packets for decoding ?

  15 octobre 2013, par mathieujofis

  I'm using MediaCodec to decode h264 packets that were encoded with ffmpeg. When I decode with ffmpeg, the frames display fine. However, when I decode with the MediaCodec hardware decoder I sometimes get black bars that show up in the middle of the frame. This only happens if the encoding bitrate is set high enough (say upwards of 4000000) so that any given AVPacket size becomes above 95000 or so. It seems like MediaCodec (or the underlying decoder) is truncating the frames. Unfortunately, I need the quality so the bitrate can't be turned down. I've verified that the frames aren't being truncated elsewhere, and I've tried setting MediaFormat.KEY_MAX_INPUT_SIZE to something higher.

  Has anyone ran into this issue or know of a way I can work around it?

  I've attached an image of random pixels that I rendered in OpenGL and then decoded on my Galaxy S4.