Sur d’autres sites (6353)

• 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

• FFMPEG screen grab of windows desktop and then exporting to multiple bandwidth ts and m3u8 files with master playlist

  26 juillet 2018, par Tank Daniels

  Forgive me as this is my first post as I’m really stuck and need help. My boss needs me to screen capture a windows desktop as input and be able to output at least four outputs dependent on bandwidth. Each output "Stream"(im guessing is the right terminology) must have its own .ts files and .m3u8 files, along with a master m3u8 playlist that lists the four individual m3u8 files.

  Every attempt ive made only produces a master m3u8 file with a single listing of an output stream. (Code enclosed below).

  The end result I need to produce is to have a master m3u8 that can go into a webpage that can stream mp4 hls of the users screen grab and that video output will be changed dependant upon the users bandwidth available. If you can please help me with any advice I will be eternally grateful as I need to impress my new boss in my new job, and I’ve been working on this for ages now with no joy.

  Example :
  This is what I need it to look like.

  What the M3U8 needs to look like

  Example :
  This is what it actually looks like now.

  What the current M3U8 actually looks like when i run my code

  Below is the code I am currently using. Please help.

  ffmpeg -f dshow -i video="UScreenCapture":audio="virtual-audio-capturer" -master_pl_name master.m3u8 -master_pl_publish_rate 30 -tune fastdecode -vf scale=w=640:h=360:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -c:v h264 -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod  -b:v 800k -maxrate 856k -bufsize 1200k -b:a 96k -hls_segment_filename 360p_%03d.ts 360p.m3u8 -master_pl_name master.m3u8 -master_pl_publish_rate 30 -vf scale=w=842:h=480:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -c:v h264 -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 1400k -maxrate 1498k -bufsize 2100k -b:a 128k -hls_segment_filename 480p_%03d.ts 480p.m3u8 -master_pl_name master.m3u8 -master_pl_publish_rate 30 -vf scale=w=1280:h=720:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -c:v h264 -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 2800k -maxrate 2996k -bufsize 4200k -b:a 128k -hls_segment_filename 720p_%03d.ts 720p.m3u8 -master_pl_name master.m3u8 -master_pl_publish_rate 30 -vf scale=w=1920:h=1080:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -c:v h264 -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 5000k -maxrate 5350k -bufsize 7500k -b:a 192k -hls_segment_filename 1080p_%03d.ts 1080p.m3u8

  Many Thanks for looking. Chris.