I'm trying to process a remote m3u8 playlist containing (a possibly encrypted) HLS stream. The output I'm looking for is a mp4 container with MPEG-4 inside.
The playlist is a result of an ended live stream and may contain EXT-X-DISCONTINUITY tags. As I understand, there's no "built-in" way to process it and indeed, there are plenty of warnings like "Non-monotonous DTS in output stream" and the resulting file always has some playback issues.
There are a couple of options to "glue" it. On an unencrypted stream, I found concat demuxer to produce the result with the least playback problems. The command is:
LIST=chunks.list; ffmpeg -loglevel 'debug' -f concat -safe 0 -protocol_whitelist "file,http,https,tcp,tls,crypto" -i $LIST -c copy -movflags frag_keyframe -y output_concat.mp4
where chunks.list is something like:
file 'https://www.example.org/chunk1.ts'
file 'https://www.example.org/chunk2.ts'
file 'https://www.example.org/chunk3.ts'
Now, I'm trying to use concat demuxer to process encrypted chunks. I've tried passing -key and -iv options in different places and changing chunks.list to be like file 'crypto+https...' but it won't pick up encryption key:
Opening an input file: chunks.list.
[concat @ 0x7f9fb6800c00] Opening 'chunks.list' for reading
[NULL @ 0x7f9fb6007e00] Opening 'crypto+https://www.example.org/chunk1.ts' for reading
[crypto @ 0x7f9fb5700a00] decryption key not set
[concat @ 0x7f9fb6800c00] Impossible to open 'crypto+https://www.example.org/chunk1.ts'
[AVIOContext @ 0x7f9fb5700780] Statistics: 5094 bytes read, 0 seeks
chunks.list: Invalid argument
Docs mention encryption options for crypto protocol, so it looks it's just a matter of passing these in a proper way.
When, instead of using concat demuxer, I try to process and decrypt only one chunk like:
ffmpeg -i crypto+https://www.example.org/chunk1.ts -key <my_hex_key> -iv <my_iv> chunk1.ts it works fine. There's nothing wrong with the key itself, I'm able to decrypt it with other tools (openssl etc).
Is it possible for concat demuxer to handle decryption? If so, where should I pass key and iv options?
