720P@30fps H.264 encoding latency

Frank,

What latency are you refering to? I mean is it capture to display on DM365 or is it network latency from capture to encode to stream to PC decode? The answer would depend on that.

Have you referred to our IPNC Reference Design on DM365? That talks about different latencies. (www.ti.com/ipcamera)

Regards,

Anshuman

The latency I am referring to is capture to encode to displaying the video.

I was not able to find any latency information at the URL you provided.  There is a brief description of the hardware and the capability to order the reference design but no latency information that I could find.

Thank you,

Frank

Hi,

What is the latency you are targetting? what is the end application you are using?

For IPNC we have arround less than 150ms as latency. This is complete system latency from sensor capture to PC display.

ALso, in codec, we support slice based encoding for low latency usecases.

Regards,

Raghu

I sent an email to customer to make sure that <150ms is tolerable for his application.  But I believe it is.

Thank you for the explanatiion.

Hello Raghu,

What is the <150ms total latency time based on?  Is it a canned demo with the eval kit?  And what resolution is the video stream?

Thank you,

Frank

This was for 1080p@30fps on DM368 in IPNC ref  design kit.

Regards,

Raghu

Raghu,

At the beginning of this train of requests for support, I mentioned that the customer was looking at using the DM365.  So can you tell me what the complete latency is for that processor using H.264 encoding with a stream of 720p@30fps?

Thank you,

Frank

It is same for 720P@30fps i.e. <150ms .......

i mentioned 1080p as to say till max resolution for 30fps streaming.

Regards,

Raghu

Raghu Kudva said:

It is same for 720P@30fps i.e. <150ms .......

 

i mentioned 1080p as to say till max resolution for 30fps streaming.

 

Regards,

 

Raghu

 

Mr Raghu,

At the beginning of this thread, the question was what latency can be expected, then changed to 150 msec is acceptable. I also looked at the link provided - it points to selling cameras. I thnk the original poser, and myself, would like to know how to achieve the 150 msec with our code and hardware. The H264 data sheet lists a few dozen parameters for the encoder, with pretty sparse descriptions of them. So let's try: Is there some reference material on using the parameters available in the H264 encoder, such as how to specify slices and the effect on latency. Network-related latency, we understand, is affected by the variable GOP size, requiring buffers to allow the average bit rate to be less than, say, the bit rate of I-Frames alone.

Thanks,

Arthur

 

 

HI,

What exactly the latency are you looking for?

You can look at the codec datasheet on how to use slice level encoding to achieve very low latency.

In the IPNC kit, we have it done on frame based encoding and we could achieve less than 150ms.

SO with slice based approach, you can still go lower but the system becomes very complex with slice mode operation.

Regards,

Raghu

Hi Raghu,

I have been using Custom made Leopard DM368.

We are getting 450ms for N/W video streaming Latency(capture+encode+n/w+decode+display). but our target is <150 ms. We have struk here almost two months.

By enabling Slicebase encoding We can achieve 280 ms. But you are telling without slicebase itself we can achieve 150ms.

Can you please Guide me to get <150ms Latency?

Regards,

Dasari