Re: [TIProtocol-askcisco] TIP Encoder Setting issue (Teliris)

[David B. (dbenham) <db...@ci...>]

Hello Aravind

>From a quick, cursory analysis of what you said/described, it seems that
at least #9, 10 and 11 are probably being not being adhered to by the
encoder ... and thus need find a way to enable those restrictions.

 

Could you pull a copy the CTS' CMA logs and send back to us (or provide
a link to a drop box we can fetch them from)?

 

 

From: Aravind Sethuraman [mailto:ara...@te...] 
Sent: Tuesday, September 06, 2011 8:08 AM
Cc: David Benham (dbenham); tip...@li...;
Girish Kondappa
Subject: TIP Encoder Setting issue

 

Hi David et al @ cisco tip,

We have been trying to interop our TIP Client with a CTS 1000 and whilst
we are able to make calls from our TIP Client to CTS 1000m we are seeing
quality issue in the CTS decode. The CTS video is getting decoded fine
in our TIP Client. So we are wondering if CTS 1000 is extremly strict
and we are missing out some encoder settings.



If possible,Please share the encoder settings that could troubleshoot
the problem.


We are referring  1.6b profile to set the settings in our encoder and
support the following wrt the encoding standard 



1. MUST generate H264 Main Profile or High Profile (HiP), if negotiated,
compatible bit stream : Using MAIN PROFILE

2. MUST support CALVC

3. MAY support CABAC as a negotiated option Using CABAC

4. MUST support 1280x720 or 1920x1080 resolution Using 1280x720

5. MUST support fixed frame rate: 30 fps or 29.97 fps Configured to use
30fps

6. MUST generate one macro block-row per slice 

-1280x720: 45 slices per frame, each slice must be 80 macro blocks in
length Using 45 * 80 

-1920x1072: 67 slices per frame, each slice must be 120 macro blocks in
length

7. MUST support deblocking_filter_control_present = 1 &
disable_deblocking_filter_idc = 1 Added

8. MUST only use inter-prediction blocks of size 16x16 Couldn't find
this setting in our encoder

9. MUST only use one reference picture and that reference picture must
be the immediate previous frame or a long term reference picture
Couldn't find this setting in our encoder

10. Each NAL MUST be less than 3320 bytes in size Couldn't find this
setting in our encoder

11. POC (Picture Order Count) MUST increment by 2 every frame Couldn't
find this setting in our encoder

12. MUST NOT USE SPS IDs in the range of 10 to 20 Uses 0 

13. Long term reference pictures (LTRPs) MAY be used for error
concealment. LTRPs requires max_num_ref_frames>=3. LTRPs use H.264
standard picture buffer management. MUST support long_term_frame_idx <
2, MUST use memory_management_control_operation = 6. LTRPs are optional
and can be disabled. Ignored

14. Gradual decoder refresh pictures (GDRs) MAY be used at the start of
a sequence instead of an instantaneous decoder refresh picture (IDR). A
recovery point SEI precedes the GDR. The SEI always has the
broken_link_flag set to 0. GDRs are optional and can be disabled.
Ignored

15. When high profile is negotiated, MUST support
seq_scaling_matrix_present_flag=0 and pic_scaling_matrix_present_flag=0,
MUST NOT use monochrome pictures, MUST NOT use quantization matrices.
Ignored

 

Observations:

1.       When we use GOP length > 1 We see poor jitter status in the CTS
and the video is bad.

2.       We always see the black strip exactly at 2/3 from the top in
the screen. And Sometimes we have seen this strip slice  catching up
late.. But most of the time it remains black...

 

It looks like CTS Decoder is expecting specific AVC bit stream that our
encoder is not able to send..

 

There are few settings above ignored and some couldn't configure in our
encoder. Is that is causing the quality issue?
Also, is it possible to provide a guidance as to how we can debug on the
CTS side for video quality issue?

regards 



Aravind Sethuraman
Chief Software Architect
Teliris, Inc.
55 Broadway, 14th Floor, New York, NY 10006
C +1.917.355.0119 | O +1.212.490.1065 x1408 | F +1.212.269.2869