From 643fd8a198ddb67225f5edd503f8f151d13635a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Reimar=20D=C3=B6ffinger?= <Reimar.Doeffinger@gmx.de>
Date: Sat, 4 Jul 2009 18:20:35 +0000
Subject: [PATCH] Add a got_picture flag to MJpegDecodeContext which indicates
if its picture element is valid. Skip the code handling SOS and EOI if not,
since it can not work without a valid AVPicture. This fixes a crash with
mjpeg/smclockmjpeg.avi.1.0 from issue 1240 where the decoder returned an
invalid AVPicture.
Originally committed as revision 19342 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
libavcodec/mjpegdec.c | 10 ++++++++++
libavcodec/mjpegdec.h | 1 +
2 files changed, 11 insertions(+)
diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 90b87f412b3..b5f8281cc1a 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -338,6 +338,7 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
}
s->picture.pict_type= FF_I_TYPE;
s->picture.key_frame= 1;
+ s->got_picture = 1;
for(i=0; i<3; i++){
s->linesize[i]= s->picture.linesize[i] << s->interlaced;
@@ -1249,6 +1250,7 @@ int ff_mjpeg_decode_frame(AVCodecContext *avctx,
int start_code;
AVFrame *picture = data;
+ s->got_picture = 0; // picture from previous image can not be reused
buf_ptr = buf;
buf_end = buf + buf_size;
while (buf_ptr < buf_end) {
@@ -1410,6 +1412,10 @@ int ff_mjpeg_decode_frame(AVCodecContext *avctx,
if ((s->buggy_avid && !s->interlaced) || s->restart_interval)
break;
eoi_parser:
+ if (!s->got_picture) {
+ av_log(avctx, AV_LOG_WARNING, "Found EOI before any SOF, ignoring\n");
+ break;
+ }
{
if (s->interlaced) {
s->bottom_field ^= 1;
@@ -1434,6 +1440,10 @@ eoi_parser:
}
break;
case SOS:
+ if (!s->got_picture) {
+ av_log(avctx, AV_LOG_WARNING, "Can not process SOS before SOF, skipping\n");
+ break;
+ }
ff_mjpeg_decode_sos(s);
/* buggy avid puts EOI every 10-20th frame */
/* if restart period is over process EOI */
diff --git a/libavcodec/mjpegdec.h b/libavcodec/mjpegdec.h
index 5a77759b3ce..9ef8987db3c 100644
--- a/libavcodec/mjpegdec.h
+++ b/libavcodec/mjpegdec.h
@@ -81,6 +81,7 @@ typedef struct MJpegDecodeContext {
int quant_index[4]; /* quant table index for each component */
int last_dc[MAX_COMPONENTS]; /* last DEQUANTIZED dc (XXX: am I right to do that ?) */
AVFrame picture; /* picture structure */
+ int got_picture; ///< we found a SOF and picture is valid, too.
int linesize[MAX_COMPONENTS]; ///< linesize << interlaced
int8_t *qscale_table;
DECLARE_ALIGNED_16(DCTELEM, block[64]);
--
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