2391124_en-US

[#1]

Does v4l2h265enc preserve input frame order?

We use v4l2h265enc on i.MX95 for real-time metadata insertion.

Since metadata is injected after the encoder on a per-access-unit basis, we need to know whether output access units can be emitted in a different order from incoming raw frames.

• Does the i.MX95 HEVC encoder generate B-frames?
• If yes, is there a V4L2 control to disable them?
• Can output access units be guaranteed to remain in input order?
• Is there a low-latency configuration recommended ?

Our current pipeline looks like :

... ! v4l2h265enc ! h265parse ! custom_sei_injector ! rtph265pay

Thank you in advance,

Sincerely,

LM

Re: Does v4l2h265enc preserve input frame order?

Hello,

1. According to reference manual, i.MX95 H.265/HEVC encode is I/P-picture only and B-frame are not generated.

2. There is no need to disable them. 

3. Since the encoder only produces I/P pictures and does not encode B-frames, there is no reordering to consider

4. Low latency tuning should focus on actual V4L2 controls, DMA buffer IO, and downstream buffering rather than disabling B-frames, you can use this post as reference:

https://community.nxp.com/t5/i-MX-Graphics/i-MX95-VPU-H265-latency-and-performance-v4l2h265enc-v4l2h...

Best regards.