[Mp4-tech] [Loss simulator JVT P069] [H264 AVC]

[Anne Sophie Bacquet]

Dear experts,
I'm a french student currently working on H.264 AVC and its scalable
extension.
I wanted to use the loss simulator with AVC bitstream but I encountered
several problems...
I encode the Foreman sequence at QCIF format at 7.5Hz using JM12_2 as
specified in VCEG-N79r1.
The resulting bitstream is called flux3.264 and weighted...87.865Ko, it is
composed by 38 frames and is attached.
The encoding parameters I used are:
- No B frame
- 1400 byte for each slice (encoder option:  slice mode:2 and slice
argument:1400)
- I change the QP to achieve 144kbit/s ( calculated by adding 40 byte for
each frame as specified in VCEG-N79r1).
**
When i decode this stream; everything is OK.
When i pass it through the simulator everything is OK with the 4 error files
(20,10,5 and 3%).
The lost frame are for the two first respectively
:3,4,7,8,16,20,21,24,29,31,38 and 7,
16, 17, 18, 21, 32,34
But with the first error file, when decoding (frame or motion copy option)
i've got the following error message and the decoding stops at frame
17:  *duplicate
frame_num in short-term reference picture buffer *. (Please find attach the
output text file :sortie_loss1.txt) .
 With the second error file, when decoding (frame or motion copy option)
i've got the following error message and the decoding stops at frame
14:*RefPicList0[
num_ref_idx_l0_active_minus1 ] is equal to 'no reference picture' *,
*invalid bitstream*  . (Please find attach the output text file
:sortie_loss2.txt.)

However,
  When i use antother bitstream, the lost frames, error message are the same
and the decoding stops at the same frames (17 and 14)??
To finish, when i use a bitstream with B picture, the lost frame are the
same but the decoding is OK...
I Hope you can help me resolving theses problems.
I thank you in advance.
Best Regards
Anne Sophie Bacquet
IEMN DOAE
UVHC Valencinnes
France
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