ffmpeg – How to update this script to generate HLS video with different resolution streams?

admin

I have the following FFmpeg script:

ffmpeg -i video.mp4 -i video.vtt \
 -map 0:v -map 0:a:0 -map 1 \
 -s:v:0 1080x1920 -c:v:0 h264 -b:v:0 500K \
 -c:a:0 copy -c:a:1 copy -c:a:2 copy -c:s webvtt \
 -f hls -hls_playlist_type vod -var_stream_map "v:0,a:0,s:0" \
 -master_pl_name video.m3u8 -hls_time 6 -hls_list_size 0 -hls_allow_cache 1 -start_number 1 \
 -hls_segment_filename "output/hls/%v/seg-%d.ts" output/hls/%v/index.m3u8

Currently it only produces one 1080×1920 stream, how do I produce more lower resolution ones so it can adjust based on client bandwidth?

Also, I’ve noticed that it doesn’t add the reference to the VTT file to the master HLS playlist; I had to add this manually but is there a way to make FFmpeg do it for me?

#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subs",NAME="English",DEFAULT=YES,AUTOSELECT=YES,FORCED=NO,LANGUAGE="en",CHARACTERISTICS="public.accessibility.transcribes-spoken-dialog",URI="0/index_vtt.m3u8"

I’ve tried this, but I get an argument error:

ffmpeg -i video.mp4 -i video.vtt \
 -map 0:v -map 0:a:0 -map 1 \
 -s:v:0 1080x1920 -c:v:0 h264 -b:v:0 500K \
 -s:v:1 720x1280 -c:v:1 h264 -b:v:1 300K \
 -s:v:2 480x854 -c:v:2 h264 -b:v:2 150K \
 -c:a:0 copy -c:a:1 copy -c:a:2 copy -c:s webvtt \
 -f hls -hls_playlist_type vod -var_stream_map "v:0,a:0,s:0 v:1,a:1 s:1 v:2,a:2 s:2" \
 -master_pl_name video.m3u8 -hls_time 6 -hls_list_size 0 -hls_allow_cache 1 -start_number 1 \
 -hls_segment_filename "output/hls/%v/seg-%d.ts" output/hls/%v/index.m3u8

Read more here: Source link