Hi all, I'm trying to convert a video into two HLS streams. This file has one video track, one audio track, and seven subtitle tracks, only three of which I am interested in.
The resulting HLS streams will be a "high quality" and "standard quality" video stream, which, through the magic of var_stream_map, use the same audio track. These streams are played back via a hls.js-based player. Here is the call to ffmpeg to produce the two streams, sans subtitles: ffmpeg -i "input_file.mkv" \ -filter_complex "[0]split=2[s1][s2];[s1]scale='min(1920,iw)':-2[hd];[s2]scale='min(1280,iw)':-2[sd]" \ -map '[hd]' -c:v:0 libx264 -b:v:0 3800k \ -map '[sd]' -c:v:1 libx264 -b:v:1 2000k \ -map 0:1 -c:a:0 aac -b:a:0 192k -ac 2 \ -var_stream_map "a:0,agroup:audio v:0,agroup:audio v:1,agroup:audio" \ -f hls -master_pl_name master.m3u8 -hls_time 4 -hls_list_size 0 -hls_segment_type fmp4 -hls_segment_filename "live_%v_%04d.ts" "live_%v.m3u8" If I want to add subtitles, I have to first convert them to webvtt by adding: -map '0:2' -c:s:0 webvtt \ -map '0:3' -c:s:1 webvtt \ -map '0:4' -c:s:2 webvtt However, I'm not sure how to add my subtitles to the variant stream map. I assumed at first that I could use "sgroup" in the same manner as "agroup": -var_stream_map "a:0,agroup:audio s:0,sgroup:subtitle s:1,sgroup:subtitle s:2,sgroup:subtitle v:0,agroup:audio,sgroup:subtitle v:1,agroup:audio,sgroup:subtitle" However, I get this error: >No streams to mux were specified >Could not write header for output file #0 (incorrect codec parameters ?): >Invalid argument >Error initializing output stream 0:1 -- So it seems like s: cannot be alone in its own variant stream. If I drop the third subtitle track, I can get the first two to show up properly in master.m3u8 like this: -var_stream_map "a:0,agroup:audio v:0,agroup:audio,s:0,sgroup:subtitles v:1,agroup:audio,s:1,sgroup:subtitles" But of course this limits me to only as many subtitle tracks as I have video streams. Does anyone know what var_stream_map syntax I should use to get my third subtitle track to show up? Thanks, Michael (I'm using a static ffmpeg build; here's the version info:) ffmpeg version N-54088-gb0203fa72b-static https://johnvansickle.com/ffmpeg/ Copyright (c) 2000-2020 the FFmpeg developers built with gcc 8 (Debian 8.3.0-6) configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg libavutil 56. 58.100 / 56. 58.100 libavcodec 58.105.100 / 58.105.100 libavformat 58. 54.100 / 58. 54.100 libavdevice 58. 11.101 / 58. 11.101 libavfilter 7. 87.100 / 7. 87.100 libswscale 5. 8.100 / 5. 8.100 libswresample 3. 8.100 / 3. 8.100 libpostproc 55. 8.100 / 55. 8.100 _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
