H.264 IPP samples: Incomplete frame decoded with trimmed file

[Pascal_Binggeli]

Hello

I've got a video sample from an AVCHDcamcorder. The file has been trimmed to remove some frames at the beginning. The H.264 stream startswith an I (non-IDR) frame.

The GOP for the resulting streamlooks like this: IBBPBB...

The resulting display order corresponding to the frames BBI...

Theproblem is that the first Bs cannot be decoded completlyastheyrefersprevious frames that have been trimmed from the file. My understanding is that the decoder could detect this situation as the first I-frame in the stream is not an IDR frame and is notable to decode the following B frames.

As an example, ffdshow detects this situation and skips the first two B fields, resulting in a cleaner output for the user.

See attached01_Trimmed.mtsas an example to reproduce the issue.

The problem exists both with h.264 decoder console sample and the h.264 video decoder.

Thanks for your time,
Pascal
H.264 starter

[Chao_Y_Intel]

Hi Pascal,

Which application in UMC sample did you test? For the attached stream, I checked with the latest IPP 6.1 update 6. The splitter does not be correctly initialized with the stream.

Thanks,
Chao

[squinn92]

Pascal,

Were you able to resolve this issue? I am having a similar problem when seeking through the AVCHD 1080i media. Since the first two B frames in this case should refer to the I frame before them (in the GOP), they should be decoded correctly, but they are not (I am using the 2.0 Media SDK). This makes it necessary for me to discard the first two frames in the GOP when seeking. This seems like a decoder initialization issue.

Steve