Sur d’autres sites (6286)

• libavformat/matroska : Write stream durations in metadata, in the format of mkvmerge.

  5 août 2015, par Sasi Inguva

  libavformat/matroska : Write stream durations in metadata, in the format of mkvmerge.
  Compute individual stream durations in matroska muxer.
  
  Write them as string tags in the same format as mkvmerge tool does.
  Signed-off-by : Sasi Inguva <isasi@google.com>
  

  • [DH] libavformat/matroskaenc.c
  • [DH] tests/fate/wavpack.mak
  • [DH] tests/ref/acodec/tta
  • [DH] tests/ref/fate/binsub-mksenc
  • [DH] tests/ref/lavf/mkv
  • [DH] tests/ref/seek/lavf-mkv

• Using lcov With FFmpeg/Libav

  21 novembre 2011, par Multimedia Mike — Programming, code coverage, ffmpeg, lcov, libav

  Last year, I delved into code coverage tools and their usage with FFmpeg. I learned about using GNU gcov, which is powerful but pretty raw about the details it provides to you. I wrote a script to help interpret its output and later found another script called gcovr to do the same, only much better.

  I later found another tool called lcov which is absolutely amazing for understanding code coverage of your software. I’ve been meaning to use it to further FATE test coverage for the multimedia projects.

  
  
  Click for larger image
  

  Basic Instructions
  Install the lcov tool, of course. In Ubuntu, 'apt-get install lcov' will do the trick.

  Build the project with code coverage support, i.e.,

  ./configure —enable-gpl —samples=/path/to/fate/samples \
   —extra-cflags="-fprofile-arcs -ftest-coverage" \
   —extra-ldflags="-fprofile-arcs -ftest-coverage"
  make
  

  Clear the coverage data :

  lcov —directory . —zerocounters
  

  Run the software (in this case, the FATE test suite) :

  make fate
  

  Let lcov work its magic :

  lcov —directory . —capture —output-file coverage.info
  mkdir html-output
  genhtml -o html-output coverage.info
  

  At this point, you can aim your web browser at html-output/index.html to learn everything you could possibly want to know about code coverage of the test suite. You can sort various columns in order to see which modules have the least code coverage. You can drill into individual source files and see highlighted markup demonstrating which lines have been executed.

  As you can see from the screenshot above, FFmpeg / Libav are not anywhere close to full coverage. But lcov provides an exquisite roadmap.

• FFMPEG - How to transcode and segment to multiple bitrates ?

  25 juillet 2014, par ipegasus

  I would like to know how to use FFMPEG to transcode video (Prores codec) and segment videos to multiple bitrates. Is it possible to do it in one command ?

  Current working solution with X264 :

  1. Encode Videos Using X264.

     /home/ubuntu/bin/ffmpeg -y -i "$video_path" -threads 1 -f mpegts \
     -acodec libfaac -ab 64k -ar 44100 -vcodec libx264 -vprofile baseline -x264opts "fps=12:keyint=36:bitrate=200" -s 416x234 "$DIR_VIDEO_OUTPUT/$filename"/p1.ts \
     -acodec libfaac -ab 64k -ar 44100 -vcodec libx264 -vprofile baseline -x264opts "fps=12:keyint=36:bitrate=400" -s 480x270 "$DIR_VIDEO_OUTPUT/$filename"/p2.ts \
     -acodec libfaac -ab 64k -ar 44100 -vcodec libx264 -vprofile baseline -x264opts "fps=24:keyint=72:bitrate=600" -s 640x360 "$DIR_VIDEO_OUTPUT/$filename"/p3.ts \
     -acodec libfaac -ab 64k -ar 44100 -vcodec libx264 -vprofile baseline -x264opts "fps=24:keyint=72:bitrate=1200" -s 640x360 "$DIR_VIDEO_OUTPUT/$filename"/p4.ts \
     -acodec libfaac -ab 64k -ar 44100 -vcodec libx264 -vprofile main -x264opts "fps=24:keyint=72:bitrate=1800" -s 960x540 "$DIR_VIDEO_OUTPUT/$filename"/p5.ts \
     -acodec libfaac -ab 64k -ar 44100 -vcodec libx264 -vprofile main -x264opts "fps=24:keyint=72:bitrate=2500" -s 960x540 "$DIR_VIDEO_OUTPUT/$filename"/p6.ts \
     -acodec libfaac -ab 64k -ar 44100 -vcodec libx264 -vprofile main -x264opts "fps=24:keyint=72:bitrate=4500" -s 1280x720 "$DIR_VIDEO_OUTPUT/$filename"/p7.ts

  2. Using an extrenal segmenter

     cd $DIR_VIDEO_OUTPUT/$filename
     mkdir M3U8
     for p in p1 p2 p3 p4 p5 p6 p7 ; do mkdir $DIR_VIDEO_OUTPUT/$filename/M3U8/$p.seg ; (cd M3U8 ; m3u8-segmenter —input $DIR_VIDEO_OUTPUT/$filename/$p.ts —duration 7 —output-prefix $p.seg/$p —m3u8-file $p.m3u8 —url-prefix "") ; done

  3. And finally manualy the individual playlists are joined into one

     echo ’

     EXTM3U

     EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=264000,RESOLUTION=416x234

     p1.m3u8

     EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=464000,RESOLUTION=480x270

     p2.m3u8

     EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=664000,RESOLUTION=640x360

     p3.m3u8

     EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1264000,RESOLUTION=640x360

     p4.m3u8

     EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1864000,RESOLUTION=960x540

     p5.m3u8

     EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2564000,RESOLUTION=960x540

     p6.m3u8

     EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=4564000,RESOLUTION=1280x720

     p7.m3u8’ >> $filename.m3u8
     cd "$DIR_VIDEO_OUTPUT/$filename"/
     sudo rm *.ts