How do I create playlists/different bandwidth wit ffmpeg? - servlets

Question

I am trying to create a hls stream out of an .mp4 file. So far I can create a manifest + .ts files, but I don't have a playlist.m3u8 to deside which manfest I should give the users based on their bandwith. How do I do that?
Here is my current command which creates HLS streams (no playlist):
ffmpeg -i test.mp4 -codec copy -vbsf h264_mp4toannexb -map 0 -f segment -segment_list out.m3u8 -segment_time 10 out%03d.ts
What this creates is out.m3u8:
#EXTM3U
#EXT-X-TARGETDURATION:10
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:10,
out.ts
#EXTINF:10,
out.ts
What I want to create:
#EXTM3U
#EXT-X-STREAM-INF:PROGRAM-ID=1, BANDWIDTH=860000
low.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1, BANDWIDTH=512000
medium.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1, BANDWIDTH=160000
high.m3u8

Answer 1

To do adaptive streaming with HLS first of all you need to encode your video at the bitrates you want to support. Take a look at Apple's encoding recommendations for some examples.
Once you've done that, you then need to segment each video and generate a playlist for it. The final step is to create a master playlist where you add the URLs of the variant playlists and information about each stream, such as the bandwidth, resolution, and so on - this is the playlist you will use as the video source for the player.
For example, let's assume that your source video was shot in 1080p and you want to generate a 360p variant with a video bitrate of 1200k. You could something like that with the following ffmpeg command:
ffmpeg -i 1080p.mov -c:v libx264 -vprofile baseline -vlevel 3.1 -s 640x360 -b:v 1200k -strict -2 -c:a aac -ar 44100 -ac 2 -b:a 96k 360p.mov
Note that the (source) video you generate the variants from needs to be high quality - you can't encode a 1080p video from a 720p one (without upscaling).
Next, run the command similar to the one in your question to generate the playlist and the segments for this video:
ffmpeg -i 360p.mov -codec copy -vbsf h264_mp4toannexb -map 0 -f segment -segment_time 10 -segment_format mpegts -segment_list 360p/playlist.m3u8 -segment_list_type m3u8 360p/fileSequence%d.ts
Now create a master playlist and add the (relative) URL of the playlist you just created. So something like this:
#EXTM3U
#EXT-X-STREAM-INF:BANDWIDTH=1228800,CODECS="mp4a.40.2,avc1.4d401e",RESOLUTION=640x360
360p/playlist.m3u8
(The bandwidth attribute should also take into account the bitrate of the audio, which I haven't done here.)
Repeat the process for the other variants.
The player will use the information about the available streams in the playlist, and the available bandwidth at the time, to determine which stream is the most appropriate to play.