muxing h.264 and aac in MP4

[malikcis]

Hi,

Is there a way (library, framework, source code etc...) to multiplex H.264 and AAC in a MP4 file format on a frame by frame and audio chunk by audio chunk basis?
There are tons of libraries but they are all file based.
Thanks,

malikcis

[Guest]

Originally Posted by malikcis

on a frame by frame and audio chunk by audio chunk basis

Please explain what this means.

[LoRd_MuldeR]

What about those?
* https://github.com/silverfilain/L-SMASH
* http://sourceforge.net/projects/gpac/

For usage example, see here:
http://git.videolan.org/?p=x264.git;...t/mp4_lsmash.c

[malikcis]

Originally Posted by neuron2

Please explain what this means.

The basic idea is to mux an audio/video stream as follows:

initialize_mp4_muxer("file.mp4");
initialize_hw_framegrabber();

while(1)
{
get_h264_frame(pVidBuffer);
get_aac_audio_chunk(pAudChunk);
mp4_mux(pVidBuffer, pAudChunk);
}
close_all_resources();

[LoRd_MuldeR]

Did you check out the above links?

[malikcis]

Originally Posted by LoRd_MuldeR

Did you check out the above links?

LoRd_MuldeR,

Ok I see. however write_frame() from mp4_lsmash.c only shows how to mux h.264 frame but not AAC audio.


Malikcis

[LoRd_MuldeR]

Originally Posted by malikcis

LoRd_MuldeR,

Ok I see. however write_frame() from mp4_lsmash.c only shows how to mux h.264 frame but not AAC audio.

Indeed, the write_frame() method in x264 does not write AAC audio, because x264 doesn't mess with audio. But the code should give you the idea how to do it

Obviously, you would need to setup two tracks rather than a single one (cf. set_param() method) and then append the audio and video samples to the audio and video track, respectively (cf. write_frame() method).

[VFR maniac]

Originally Posted by malikcis

LoRd_MuldeR,

Ok I see. however write_frame() from mp4_lsmash.c only shows how to mux h.264 frame but not AAC audio.


Malikcis

Official x264's repo omits some features for convenience.
About muxing both audio and video, x264_L-SMASH may be helpful, though it's somewhat old.
https://github.com/silverfilain/x264...h/output/mp4.c

x264_L-SMASH writes audio frames for each write_frame().
The code is asymmetry.
L-SMASH muxes chunk by chunk internally from input frames unless exceeding max_async_tolerance.
You can append video frames and audio frames in arbitrary timing as L-SMASH muxer app does.
http://repo.or.cz/w/L-SMASH.git/blob/HEAD:/muxer.c#l976

If you want to interleave each video frame and each audio chunk, set duration of video frame to max_chunk_duration.

[malikcis]

Originally Posted by VFR maniac

Official x264's repo omits some features for convenience.
About muxing both audio and video, x264_L-SMASH may be helpful, though it's somewhat old.
https://github.com/silverfilain/x264...h/output/mp4.c

x264_L-SMASH writes audio frames for each write_frame().
The code is asymmetry.
L-SMASH muxes chunk by chunk internally from input frames unless exceeding max_async_tolerance.
You can append video frames and audio frames in arbitrary timing as L-SMASH muxer app does.
http://repo.or.cz/w/L-SMASH.git/blob/HEAD:/muxer.c#l976

If you want to interleave each video frame and each audio chunk, set duration of video frame to max_chunk_duration.

Thank you,
This indeed seems to be a possible way.
The hard part (implementation) remains though...