carial
Posts: 23
Joined: Mon Jan 08, 2018 6:01 am

Problem on setting avc parameters

Fri Jan 12, 2018 12:42 am

I have problem to set h264(avc) encoding parameters. SetParameter failed with error code 0x80001005 (OMX_ErrorBadParameter). The following is part of the code:

OMX_VIDEO_PARAM_AVCTYPE avcConfig;
memset(&avcConfig, 0, sizeof(OMX_VIDEO_PARAM_AVCTYPE));
avcConfig.nSize = sizeof(OMX_VIDEO_PARAM_AVCTYPE);
avcConfig.nVersion.nVersion = OMX_VERSION;
avcConfig.nPortIndex = OMX_VIDENC_OUTPUT_PORT;

OMX_GetParameter(ILC_GET_HANDLE(handle->video_encode), OMX_IndexParamVideoAvc, &avcConfig);

avcConfig.nPFrames = 1;
avcConfig.nBFrames = 4;
avcConfig.eProfile = OMX_VIDEO_AVCProfileMain;
avcConfig.eLevel = OMX_VIDEO_AVCLevel3;
avcConfig.bEntropyCodingCABAC = OMX_FALSE;
avcConfig.nAllowedPictureTypes = 3;
avcConfig.nRefFrames = 1;

I am not sure what is wrong with the above settings. From OMX_video.h, "nPFrames" means number of P frames between I frames, and "nBFrames" means number of B frames between I frames. So the above setting should generate the following GOP structure?

I B B P B B I...

Could someone help me on this? Thanks!

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5081
Joined: Wed Dec 04, 2013 11:27 am
Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: Problem on setting avc parameters

Fri Jan 12, 2018 7:40 am

B frames aren't supported by the hardware. nBFrames must be set to 0.
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