Newest 'ffmpeg' Questions - Stack Overflow

Les articles publiés sur le site

• ffmpeg video encoding for mobile devices

  27 janvier 2012, par TimGL

  I'm trying to encode the video file from f4v to mp4 for mobile devices and using 2 different ffmpeg versions with the same configuration files. Encoding goes ok for both files. The one that I convert using ffmpeg version N-32754-g936d4d4-Sherpya failing to play on my blackberry. This is the command line that I'm using:

  ffmpeg.exe -i some.avs -vcodec libx264 -b 500k -r 24 -acodec libfaac -ab 128k -ar 48000 -ac 2 -threads 0 -coder 0 -bf 0 -refs 1 -level 30 -maxrate 10000000 -bufsize 10000000 -y test.mp4

  The vido playes ok when I convert it using FFmpeg version SVN-r13712 Could you give me some light on where the issue couls be?

• ffmpeg pts not setted while encoding

  27 janvier 2012, par Sambatyon

  I'm encoding a video in format h264 using libavcodec (x264). The encoding is done with this code:

  frame_->data[0] = buffer;
  frame_->data[1] = buffer + width * height;
  frame_->data[2] = buffer + (width * height) + ((width >> 1) * (height >> 1));
  frame_->pts = frame_count;  
  
  bytes_written = avcodec_encode_video(context, buffer, 
                                        kBufferSize, frame_);
  

  where AVFrame *frame_ and AVCodecContext *context_ My problem is when I try to pack the video using ffmpeg, I always recieve the message [mp4 @ 0000000003A19F60] pts has no value moreover he attempts to guess the pts based on the bitrate which at the end generates much slower videos.

  It is as is the line frame_->pts = frame_count; didn't have any effect. Any suggestions?

• Linux Platform : Enlarge video screen size N times

  27 janvier 2012, par Susan Mayer

  I am looking for a application on Linux platforms (Ubuntu/CentOS etc) that can enlarge video size N times. N could be any number, like 1.5, 4 etc

  For example, if I have a video with screen size 100*200, I want to make it 1.5 times larger, that will be: 150*300. Of course, I will expect the video quality to drop but it doesnt matter.

  I am not sure whether ffmpeg has this function but a quick Google lands me nowhere. So I am here now.

  Thanks a lot!

• Chroma key software (script)

  26 janvier 2012, par Noda Caju

  I have thousands of small videos in HDTV quality. All with green chroma key. I need to change green colour for a static image (company logos).

  There are several softwares that can change chroma key, but they are only one by one file. This will take years to be completed.

  Is there a software (script) that I can make this automatic?

• Create WebM with FFmpeg programatically

  25 janvier 2012, par Kage

  I have VP8 encoded frames that so far I am saving into IVF format, however, I want to take these frames and put them into a WebM format.

  I am using FFmpeg programmatically on Android with libvpx enabled.

  I really have no idea how to put my frames into a WebM file and there is so little information out there about this.

  Could anyone help me in the right direction or provide me with a link to some help?

  Edit:

  Examples of outputting encoded frames into any other container would also be appreciated