[M4IF Technotes] Use of B-frames

[Ramkishor Korada]

Hi,
     Answers to some of the questions.
----- Original Message -----
From: "Gregorio Litinsky" <gregorio_litinsky   hotmail.com>
To: <technotes   lists.m4if.org>
Sent: Sunday, October 14, 2023 8:54 PM
Subject: [M4IF Technotes] Use of B-frames
> Dear Colleagues:
>
> I am investigating the use and benefits of B-frames for low bit rate
> communication.
>
> As you all probably know, B-frames are commonly used in MPEG-1 and MPEG-2
> compression. They are bi-directionally predicted in the same fashion from
> either preceding or subsequent I- or P-frames. Where a P-frame generally
> requires 1/2 of the data of an I-frame, a B-frame requires only 1/4.
>
> Could you please help me with the following questions:
>
> 1. What is the minimum bit and frame rate where B-frames improve the
> quality? A minimum of 10 fps and 144 Kbps has been mentioned.
> 2. Which profile supports B-frames? MPEG-4 Simple  Scalable Visual Profile
> supports B-frames, but I understand that this profile requires support for
> temporal and spatial scalability? Is it possible from a compliance
> perspective to only support B-frames in the MPEG-4 Simple  Scalable Visual
> Profile?

 Many profiles supoort B frames. Refer to Section 9 on profiles and levels
for further details.
> 3. H.263 (Profile 8) does also support B-frames (Annex M). Is this codec
> better than MPEG-4 Simple  Scalable Visual Profile?
> 4. Does the MPEG-4 Advanced Simple Visual Profile support B-frames?

 Yes..
> 5. Does the new H.26L codec support B-frames?
    Yes.
> 6. Which profile/codes do you recommend for supporting B-frames?

     In case of MPEG-4, advanced simple profile.
> 7. Where can I find documentation about profiles/codecs supporting
B-frames?
>
     Section 9.
> Best Regards,
>
> Gregorio Litinsky
> Consultant
>

Architect - Video
Multimedia Technologies Division
Emuzed India
Bangalore
www.emuzed.com