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| author | Anton Khirnov <anton@khirnov.net> | 2013-03-16 13:08:32 +0100 |
|---|---|---|
| committer | Anton Khirnov <anton@khirnov.net> | 2013-03-18 15:36:10 +0100 |
| commit | ce0124acacd9acbfdc267464a4b52947a249b4bd (patch) | |
| tree | 4dd29d99b6ada89f27f9873e063b4357e6f5719d | |
| parent | 50c449ac24fbb4c03c15d2e2026cef2204b80385 (diff) | |
| download | ffmpeg-ce0124acacd9acbfdc267464a4b52947a249b4bd.tar.gz | |
mpeg12: do not fail on zero dimensions in the sequence header.
The total frame size is a combination of the 12 bits in the sequence
header and 2 more bits in the the sequence extension. While the
specification explicitly forbids the dimensions from the sequence header
from being 0 (thus ruling out multiples of 4096), such videos
apparrently exist in the wild so we should attempt to decode them.
Based on a patch by Michael Niedermayer <michaelni@gmx.at>
Fixes Bug 416.
| -rw-r--r-- | libavcodec/mpeg12.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c index c32055d609..bd018d377f 100644 --- a/libavcodec/mpeg12.c +++ b/libavcodec/mpeg12.c @@ -1974,8 +1974,12 @@ static int mpeg1_decode_sequence(AVCodecContext *avctx, width = get_bits(&s->gb, 12); height = get_bits(&s->gb, 12); - if (width <= 0 || height <= 0) - return -1; + if (width == 0 || height == 0) { + av_log(avctx, AV_LOG_WARNING, "Invalid horizontal or vertical size " + "value.\n"); + if (avctx->err_recognition & AV_EF_BITSTREAM) + return AVERROR_INVALIDDATA; + } s->aspect_ratio_info = get_bits(&s->gb, 4); if (s->aspect_ratio_info == 0) { av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n"); @@ -2271,6 +2275,12 @@ static int decode_chunks(AVCodecContext *avctx, break; case PICTURE_START_CODE: + if (s2->width <= 0 || s2->height <= 0) { + av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n", + s2->width, s2->height); + return AVERROR_INVALIDDATA; + } + if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) && s->slice_count) { int i; |