Hi everyone, I am currently having a problem trying to implement adaptive bitrate of HLS live streams with the help of ffmpeg.
I basically have a RTMP source that I'm converting into two HLS playlists: - One is just demuxing and segmenting the video into ts files, - A second of lower quality with audio only, in this case I use the libfaac codec to compress it. Here is what I am executing: #the high quality ffmpeg -i rtmp://localhost/live/$name -bsf:v h264_mp4toannexb -c:a copy -c:v copy -sc_threshold 0 -hls_time 5 -hls_list_size 3 -hls_segment_filename '/live/$name_hi/%d.ts' -hls_allow_cache 0 /live/$name_hi/index.m3u8 #the low quality ffmpeg -i rtmp://localhost/live/$name -async 1 -vsync 1 -ab 55k -bufsize 55k -vn -c:a libfaac -sc_threshold 0 -hls_time 5 -hls_list_size 3 -hls_segment_filename '/live/$name_low/%d.ts' -hls_allow_cache 0 /live/$name_low/index.m3u8 These two playlist are then combined into a global live playlist as recommended by Apple. Everything runs fine and I can perfectly play this global playlist with HTML5 coupled to this flash plugin: https://github.com/mangui/flashls My problem is when I'm playing this playlist with iOS, every once in a while the player presents an initial lag before playing normally, or even displays a black screen with just the sound. It is worth to notice that the segments in the respective playlists do not have the same duration: the high quality playlist #EXTM3U #EXT-X-VERSION:3 #EXT-X-ALLOW-CACHE:NO #EXT-X-TARGETDURATION:6 #EXT-X-MEDIA-SEQUENCE:7 #EXTINF:4.000000, 7.ts #EXTINF:6.000000, 8.ts #EXTINF:4.000000, 9.ts the low quality playlist #EXTM3U #EXT-X-VERSION:3 #EXT-X-ALLOW-CACHE:NO #EXT-X-TARGETDURATION:6 #EXT-X-MEDIA-SEQUENCE:7 #EXTINF:4.992300, 7.ts #EXTINF:4.992289, 8.ts #EXTINF:5.015511, 9.ts When I am playing only the high quality playlist, the playback is perfect. Does it have to do with a misalignement of the keyframes betwseen the two playlists and how can I fix that? Thanks! _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
