TDA4AL-Q1: How to enable lossless mode in v4l2h264enc?

user4836286

Part Number: TDA4AL-Q1

Hello,

"v4l2-ctl -d 1 -l" shows "hevc_lossless_encoding" codec control, and I tried 'video/x-raw, width=(int)1920, height=(int)1536, framerate=(fraction)30/1, format=(string)NV12, interlace-mode=(string)progressive, colorimetry=(string)bt601 ! v4l2h264enc extra-controls="enc,hevc_lossless_encoding=1" ! ...' gstreamer pipeline.
But lossless did not work. The size of encoded h264 was small and image quality was very low.
Please let me know how to enable lossless mode.

Best regards,

Wilson.

over 1 year ago

0 Sarabesh Srinivasan over 1 year ago

TI__Genius 17300 points

Hi Wilson,

I will test and look into this. What SDK version are you on?

Thanks,
Sarabesh S.

0 user4836286 over 1 year ago in reply to Sarabesh Srinivasan

Expert 1300 points

Hi Sarabesh,

PSDK version is 09_00_00_02_j721s2

Best regards,

Wilson

+1 Sarabesh Srinivasan over 1 year ago in reply to user4836286

TI__Genius 17300 points

Hi Wilson,

Thanks for the information. It looks like the problem is that you are using the v4l2h264 plugin to encode lossless with the hevc_lossless_encoding plugin. You should instead use a H265 (HEVC) file with the v4l2h265 plugin. When I tested with an H265 stream, I was able to successfully encode lossless. H264 (AVC) does not have lossless encode support. The pipeline I used is below:

gst-launch-1.0 filesrc location=/bbb_1080p30_short.yuv ! rawvideoparse width=1920 height=1080 format=nv12 framerate=30/1 colorimetry=bt709 ! v4l2h265enc extra-controls="enc,hevc_lossless_encoding=1" ! filesink location=/bbb_1080p_short_lossless.265

Regards,
Sarabesh S.

0 user4836286 over 1 year ago in reply to Sarabesh Srinivasan

Expert 1300 points

Hi Sarabesh,

Thanks for informing. I didn't know that lossless is a feature of h.265

Best regards,

Wilson.

0 Sarabesh Srinivasan over 1 year ago in reply to user4836286

TI__Genius 17300 points

Anytime. Glad to hear this resolved your issue and let me know if anything else comes up.

BR,
Sarabesh S.

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TDA4AL-Q1: How to enable lossless mode in v4l2h264enc?