Bug Report Index needs to be swapped in MP4 file

[Rainbow Harderwijk]

The recording into an MP4 has one "mistake" in the file: The index is placed at the end of the file.
I need to post process the file with QT Index Swapper (http://renaun.com/blog/code/qtindexswapper/) in order to get it into the beginning of the file. Is is needed in the beginning of the file, because if the have an MP4 on your website, you want to be able to see it as a user directly (stream) and not that the whole file is downloaded first.
Would be nice if this can be fixed in OBS.

Here the link of the original file on our chrch test website. It must be first fully downloaded prior playing starts:
http://www.testsitekerk.nl/component/allvideoshare/video/latest/obs-test
If we process it with QT Index Swapper than it starts playing immediately.

We are now using software http://www.nchsoftware.com/capture/index.html. In the past NCH had same problem but corrected it. We want to switch to OBS with Black Magic Intensity Shuttle to improve our set-up, however we do not want to post process recordings with QT Index Swapper, prior being able to put it on our website.

Looking forward to this fix :-)

Greetings from The Netherlands.

 

[R1CH]

The index has to be written after the file is finished. Moving the index requires a full file rewrite; this is not something OBS does as it would generate a bad experience if every time you stopped recording you had gigabytes of disk I/O for something most people will never need.

 

[Rainbow Harderwijk]

Thanks for the fast reply. Now using NCH and they are not doing a full file rewrite. After stopping recording it is immediately correct. Also QT Index Swapper goes very fast, so assume not a rewrite is done. Guess the file itself is processed.

Please have a look into how Moov Atom can be relocated:
https://code.google.com/archive/p/moovrelocator/
https://www.ffmpeg.org/doxygen/trunk/qt-faststart_8c_source.html

 

[Simes]

Look at them yourself, qt-faststart copies the entire file.

 

[Schauerland]

use custom muxer setting:

movflags=faststart

BEWARE: after you stop the recording the index will be moved to the beginning. this takes some time.
DO NOT CLOSE OR KILL OBS or your file is broken (it's also broken if your pc crashes while recording)

 

[Rainbow Harderwijk]

Thanks for your responses. Goes a bit to deep for me talking about this level of the code.
Guess if will then always be post processing.
Still though would be nice if in the Settings of OBS it could be "ticked" that automatic post-progressing-index-swap will be done in an extra output file, when recording is stopped.
Guess dreaming is free :-)

 

[Boildown]

Um, it looks like its just a custom x264 command, so it shouldn't be considered to be that hard. How much easier can you ask it to be?

 

[Schauerland]

no, not x264 - there's another input field for muxer settings - there it goes.
muxing is done by ffmpeg - this is an ffmpeg command

 

[Rainbow Harderwijk]

a) Could not find x264 option on the web to be added in the Options field. Can somebody provide that?
b) Is this also possible when QSV is used? (New PC is on order with Kabylake processor)

 

[Suslik V]

II think, fragmented mov/mp4 is a good option (Custom Muxer Settings):

movflags=frag_keyframe min_frag_duration=4000000

Just in case, OBS Studio Help Guide: https://obsproject.com/forum/resour...ware-studio-multiplatform-help-guide-pdf.365/