Tag Archives: MP4

Check key-frame alignment with MP4Box

⚠ The content of this page may be outdated.
Please refer to this page for more up to date information: https://github.com/gpac/gpac/wiki/Check-key-frame-alignment-with-MP4Box

 

Dear adaptive streaming followers,

Many of you reported issues when packaging your encoded content to respectively HLS or MPEG-DASH using GPAC (resp. the MP42TS and MP4Box tools). Most of the time, this is due to misalignment of key-frames across the different encoded qualities. In this article, we are going to show how to check key-frame alignment.
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MP4 demuxer examples

⚠ The content of this page may be outdated.
Please refer to this page for more up to date information: https://github.com/gpac/gpac/wiki/MP4-demuxer-examples

 

Dear followers,

At the request of some people, we have added to GPAC some sample applications demonstrating how to use GPAC to demux MP4 files. They are not full applications, just examples taking some MP4 files as input and displaying some information about the media samples contained in the file.

So far, we have added 3 sample applications:

  • a basic demuxer called ‘bmp4demux’ capable of reading and dispatching media access units from fragmented or non-fragmented MP4 files, progressively (i.e. while the file is being written);
  • a segment based demux called ‘segmp4demuxer‘ capable of dispatching media units from media segments, where the input data is framed.  This is what is used for the DASH support;
  • and a more advanced demuxer, called ‘fmp4demux’ capable of dispatching media units in streaming mode (i.e. reclaiming resources once media units have been dispatched), where the input data comes from fragmented mp4 but is not framed, i.e. the data in the buffer passed to the demuxer does not start or end at segment or fragment boundaries.

Continue reading MP4 demuxer examples