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[Linphone-developers] H.263 bitstream syntax error ; an FFMPEG problem?
From: |
Francois-Xavier KOWALSKI |
Subject: |
[Linphone-developers] H.263 bitstream syntax error ; an FFMPEG problem? |
Date: |
Fri, 24 Feb 2006 15:29:38 +0100 |
User-agent: |
Mozilla Thunderbird 1.0.7-1.1.fc3 (X11/20050929) |
Folks,
FYI, the H.263 video bitstream generated by FFMPEG is an H.263-1998 with
a syntax error in the picture header. This error is located in the
mandatory PTYPE bitfield. It may cause H.263 decoder to abort the stream.
----------H.263+ : MANDATORY PLUS PTYPE----------
pict_type: 000(0)
reference_picture_resampling_mode: 0(0)
reduced_resolution_update_mode: 0(0)
rounding_type: 0(0)
rtype: 0(0)
reserve, reserve, spare: *101*(5) <= should be 001(1)
The H.263 specs (I checked from H.263v1 to H.263v3) states the following:
5.1.4.3 The mandatory part of PLUSPTYPE when PLUSPTYPE present (MPPTYPE)
(9 bits)
Regardless of the value of UFEP, the following 9 bits are also
present in PLUSPTYPE:
– Bits 1-3 Picture Type Code:
"000" I-picture (INTRA),
"001" P-picture (INTER),
"010" Improved PB-frame (see Annex M),
"011" B-picture (see Annex O),
"100" EI-picture (see Annex O),
"101" EP-picture (see Annex O),
"110" Reserved,
"111" Reserved;
– Bit 4 Optional Reference Picture Resampling (RPR) mode (see Annex
P), "0" off,
"1" on;
– Bit 5 Optional Reduced-Resolution Update (RRU) mode (see Annex Q),
"0" off, "1"
on;
– Bit 6 Rounding Type (RTYPE) (see 6.1.2);
*– Bit 7 Reserved, shall be equal to "0";
– Bit 8 Reserved, shall be equal to "0";
– Bit 9 Equal to "1" to prevent start code emulation.*
--
Francois-Xavier "FiX" KOWALSKI /_ __ Tel:+33 (0)4 76 14 63 27
OpenCall Business Unit -- OCBU / //_/ Fax:+33 (0)4 76 14 51 62
Media-Processing Engineering / http://www.hp.com/go/opencall
i n v e n t
- [Linphone-developers] H.263 bitstream syntax error ; an FFMPEG problem?,
Francois-Xavier KOWALSKI <=