bluenviron/gohlslib

How to transcode the parts of a segment

captain-bugs opened this issue · 0 comments

captain-bugs commented

I want to do ABR for LHLS. Is it possible to transcode the AnexB bitstream format directly using ffmpeg or libav libraries?
for now i'm trying to store the muxerPart.videoSamples[] data in a .h264 file.

I read if i provide the SPS and PPS as extradata to AVCodecContext i can transcode it.
But not every part has SPS and PPS only the first part of every segment.

The .h264 file which I created has order like SPS, PPS, SPS, PPS, slice of IDR, slice of non-IDR ... but only the 1st part of segment has this order the other parts only have slice of non-IDR ...

And if i want to get SPS and PPS from 1st part when i unmarshal the contents of .h264 file using h264.AnnexBUnmarshal() function i get error: NALU count (546) exceeds maximum allowed (21).
even though every au that are marshalled have the prefix of []byte{0x00, 0x00, 0x00, 0x01}

  1. Is it possible to transcode the parts
  2. If yes is the adding SPS and PPS as extradata to AVCodecContext right way
  3. why h264.AnnexBUnmarshal() gives error