DM6467T H264 Encoder issues

nagendra bankupalli

hi TI,

i have some issues with DM6467t H264 encoder.

The API used to encode the video on DM6467T is (dvsdk_03_10_00_19)

status = VIDENC1_process(hEncode, &inBufDesc, &encodedBufDesc, &encoderInArgs, &encoderOutArgs);

the argument encoderOutArg is a structure contains the member called bytesGenerated
this member gives exact bytes generated after encoding the video frame.

sometimes, when the video contains small moving objects like thousands of birds flying (small moving dots in thousands number),
this parameter is returned zero by above mentioned DSP API (dm6467t) so, we have a pause in our video (we are live streaming h264 data)

could you please help me why sometimes this is happening ? is it a limitation of encoder ?

regards
Nagendra

over 8 years ago

0 Veeranna Hanchinal over 8 years ago

TI__Expert 8465 points

bytesGenerated will be zero when current frame being skipped, and this may be the reason for pause. Are you using CBR or VBR, if you are using CBR try by using VBR or increase bitrate

Thanks

0 nagendra bankupalli over 8 years ago in reply to Veeranna Hanchinal

Intellectual 360 points

thanks, TI it helped a lot......cheers!!! :)

0 nagendra bankupalli over 8 years ago in reply to nagendra bankupalli

Intellectual 360 points

hi TI,
what is the maximum bit rate that this DSP supports ?
we are encoding 2 720p videos (6Mbps+6Mbps)
regards
Nagendra

0 Prashanth Kumar15 over 8 years ago in reply to nagendra bankupalli

Mastermind 8775 points

Hi Nagendra,

Please refer datasheet with your package. It should have all the numbers and answer your query.

0 nagendra bankupalli over 7 years ago in reply to Prashanth Kumar15

Intellectual 360 points

Hi Prashanth,

thanks for the information,

one more question, is it possible to edit SPS info to enable crop at bottom ? if yes , how ?

regards
Nagendra

0 Gajanan Maske over 7 years ago in reply to nagendra bankupalli

Expert 2285 points

Hi Nagendra,

Its possible to edit the sps if frame_cropping is enabled. Below is the requirements -
- SPS Parser is requried.
- Possible rewrite the SPS before proving to decoder with framecropping information.

Regards
Gajanan

0 nagendra bankupalli over 7 years ago in reply to Gajanan Maske

Intellectual 360 points

hi Gajanan

thanks

i understood that the bit "frame_cropping_flag" has to set

and frame_crop_bottom_offset should be 'a' (effected lines would be a*2) am i correct ?

i am able to set frame_crop_bottom_offset to 5 but not 4.

could you give any example SPS to set frame_crop_bottom_offset to 4 , or is it not possible ?

regards

Nagendra

0 Veeranna Hanchinal over 7 years ago in reply to nagendra bankupalli

TI__Expert 8465 points

Hi Nagendra,

Its possible to modify the frame_crop_bottom_offset to any value by modifying the stream. Please note that the bits represented in the stream is not directly written & it will be present in Exp-Golomb bit strings and codeNum.

So while parsing the SPS, please check the pattern for below code numbers -

So for 5 ==> 00110

4 ==> 00101

Replace that number with another number in this format to get the expected behaviour.

Regards

Gajanan

0 nagendra bankupalli over 7 years ago in reply to Veeranna Hanchinal

Intellectual 360 points

Hi Gajanan

setting proper dynamic parameters of encoder engine solved the issue.

thanks for support and info

regards

Nagendra

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DM6467T H264 Encoder issues