save init.mp4 to disk

[pikachu937]

Which version are you using?

v0.22.0

Which operating system are you using?

• Linux amd64 standard
• Linux amd64 Docker
• Linux arm64 standard
• Linux arm64 Docker
• Linux arm7 standard
• Linux arm7 Docker
• Linux arm6 standard
• Linux arm6 Docker
• Windows amd64 standard
• Windows amd64 Docker (WSL backend)
• macOS amd64 standard
• macOS amd64 Docker
• Other (please describe)

Describe the issue

when saving files to disk in lowLatency and fmp4 mode, the resulting files cannot be played.

ffprobe outputs the following:
ffprobe seg355.mp4
ffprobe version 4.3.5-0+deb11u1 Copyright (c) 2007-2022 the FFmpeg developers
built with gcc 10 (Debian 10.2.1-6)
configuration: --prefix=/usr --extra-version=0+deb11u1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-pocketsphinx --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
libavutil 56. 51.100 / 56. 51.100
libavcodec 58. 91.100 / 58. 91.100
libavformat 58. 45.100 / 58. 45.100
libavdevice 58. 10.100 / 58. 10.100
libavfilter 7. 85.100 / 7. 85.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 7.100 / 5. 7.100
libswresample 3. 7.100 / 3. 7.100
libpostproc 55. 7.100 / 55. 7.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x5564c90a1a00] could not find corresponding trex (id 1)
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x5564c90a1a00] could not find corresponding track id 0
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x5564c90a1a00] trun track id unknown, no tfhd was found
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x5564c90a1a00] error reading header
seg355.mp4: Invalid data found when processing input

while files of the "ts" format are read and played perfectly

Describe how to replicate the issue

1. set var hlsEncryption, hlsServerKey, hlsServerCert
2. set var hlsVarian - lowLatency or fmp4
3. set var hlsDirectory
4. start the server
5. publish with rtsp
6. download segXXX.mp4 file from server
7. read with vlc or quicktime player

Did you attach the server logs?

yes / no

Did you attach a network dump?

yes / no

[aler9]

Hello, this is expected since MP4 segments can be decoded only after decoding an initialization file called "init.mp4".
This file is placed in the header of the HLS playlist:

#EXTM3U
#EXT-X-VERSION:7
#EXT-X-MEDIA-SEQUENCE:20
#EXT-X-INDEPENDENT-SEGMENTS
#EXT-X-TARGETDURATION:2
#EXT-X-MAP:URI="init.mp4"
#EXTINF:2,
segment.mp4
#EXT-X-ENDLIST

A HLS player usually downloads init.mp4 and segment.mp4, merges them together and passes them to the video decoder.

We can improve the server in order to save init.mp4 on the disk too, but, in order to read the segments with a normal player like VLC or FFmpeg, you'll still have to append them to init.mp4.

[pikachu937]

ok, that would be great. there are a few more questions. are you planning a permanent storage option, as well as an option to work with a database?

[aler9]

Native stream recording is tracked here: #1399

Files don't fit well with databases, therefore no database.

[pikachu937]

Files don't fit well with databases, therefore no database.

I do not agree with you. it is much easier to search for files on a disk using a known path than it is to go through all the directories and look for the desired file. the database can store file paths, size, creation date, duration, name of the stream to which the file belongs.

[aler9]

@pikachu937 i thought you were suggesting to use a database to store files, instead you are suggesting to use a database to store the file metadata, which is reasonable. It may be an improvement of the stream recording feature.

Regarding HLS, the option hlsDirectory was conceived in order to offload RAM from segments, since segments use a significant amount of space when they are kept exclusively in RAM, but at the same time performance is a requirement, therefore i'd rather not add a database. Anyway, the missing file init.mp4 will be soon added to the corresponding directory.

[pikachu937]

@pikachu937 i thought you were suggesting to use a database to store files, instead you are suggesting to use a database to store the file metadata, which is reasonable. It may be an improvement of the stream recording feature.

Regarding HLS, the option hlsDirectory was conceived in order to offload RAM from segments, since segments use a significant amount of space when they are kept exclusively in RAM, but at the same time performance is a requirement, therefore i'd rather not add a database. Anyway, the missing file init.mp4 will be soon added to the corresponding directory.

Excellent, thank you. Then I think you won't mind if I open a new ticket to add metadata storage functionality to the database?

[aler9]

init.mp4 is now saved on disk.

[pikachu937]

thank you... you are the best...

[aler9]

added in v0.22.1

[github-actions]

This issue is being locked automatically because it has been closed for more than 6 months.
Please open a new issue in case you encounter a similar problem.