MP4V on the net

MP4V on the net

Hi, I'm making video transmission software ( beta here -
using mp4v codec found in ffmpeg.

Now I'm trying to adapt IPP mp4v code. Basic code adaptations are done with mp4v enc/decoding examples provided in support site. Much much fater but

I found I have two problems.
- If some packets are dropped by network, IPP never go back decoding. All subsequent frames are not decoded.
- CHROMA_422 is defined in header but only 420 inputs seemed to be supported.

Are supports available for these?

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If I understand right you have 2 problems:

1. mp4decode sample stops after founding error in bitstream and it doesn't continue to decode the rest of bitstream.

2. mp4encode sample encodes source in 4:2:0 format only.

The answers are:

1. IPP provides a low-level blocks. mp4decode sample shows only how a application can be constructed from these block. So you should support hi-level error handler in your application yourself.

2. Yes, mp4encode sample requires source in 4:2:0 format only. IPPVC_CHROMA_422 and IPPVC_CHROMA_444 were defined for future extension of sample. In any case MPEG-4 standard deals with 4:2:0 subsampling only, so you should convert any source to 4:2:0 format.


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