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mpeg4video: ignore broken GOP headers

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Some MPEG4 cameras produce files with empty GOP headers.
This patch makes the decoder ignore such broken headers and proceed
with the following I-frame.  Without this change, the following
start code is missed resulting in the entire I-frame being skipped.

Signed-off-by: Mans Rullgard <mans@mansr.com>
This commit is contained in:
Anatoly Nenashev 2011-02-10 16:09:48 +00:00 committed by Mans Rullgard
parent 5d57846bba
commit 7a4abe5912
1 changed files with 10 additions and 9 deletions
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19
libavcodec/mpeg4videodec.c
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@ -1494,16 +1494,17 @@ end:
static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
int hours, minutes, seconds;
unsigned time_code = show_bits(gb, 18);
hours= get_bits(gb, 5);
minutes= get_bits(gb, 6);
skip_bits1(gb);
seconds= get_bits(gb, 6);
s->time_base= seconds + 60*(minutes + 60*hours);
skip_bits1(gb);
skip_bits1(gb);
if (time_code & 0x40) { /* marker_bit */
hours = time_code >> 13;
minutes = time_code >> 7 & 0x3f;
seconds = time_code & 0x3f;
s->time_base = seconds + 60*(minutes + 60*hours);
skip_bits(gb, 20); /* time_code, closed_gov, broken_link */
} else {
av_log(s->avctx, AV_LOG_WARNING, "GOP header missing marker_bit\n");
}
return 0;
}