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authorMichael Niedermayer <michaelni@gmx.at>2012-04-07 19:32:45 +0200
committerMichael Niedermayer <michaelni@gmx.at>2012-04-07 19:59:00 +0200
commita931d87727581f46373e24ac37a73d0f228e3027 (patch)
tree5016773a51292fe30d22d1f7b907e9a8877bd6a7 /libavcodec/mpeg12.c
parent6c3d6a214c6a5b0a7e9c4aa1990d1c5b290806d5 (diff)
downloadffmpeg-a931d87727581f46373e24ac37a73d0f228e3027.tar.gz
mpeg12dec: Prevent f_code from becoming invalid.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/mpeg12.c')
-rw-r--r--libavcodec/mpeg12.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 535c795899..07a00a9607 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -1368,6 +1368,7 @@ static int mpeg1_decode_picture(AVCodecContext *avctx,
f_code = get_bits(&s->gb, 3);
if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
return -1;
+ f_code += !f_code;
s->mpeg_f_code[0][0] = f_code;
s->mpeg_f_code[0][1] = f_code;
}
@@ -1376,6 +1377,7 @@ static int mpeg1_decode_picture(AVCodecContext *avctx,
f_code = get_bits(&s->gb, 3);
if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
return -1;
+ f_code += !f_code;
s->mpeg_f_code[1][0] = f_code;
s->mpeg_f_code[1][1] = f_code;
}
@@ -1536,6 +1538,11 @@ static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
s->current_picture.f.pict_type = s->pict_type;
s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
}
+ s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
+ s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
+ s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
+ s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
+
s->intra_dc_precision = get_bits(&s->gb, 2);
s->picture_structure = get_bits(&s->gb, 2);
s->top_field_first = get_bits1(&s->gb);