[FFmpeg-cvslog] eamad: use the bytestream2 API instead of AV_RL
Anton Khirnov
git at videolan.org
Sat Aug 9 19:12:44 CEST 2014
ffmpeg | branch: release/0.10 | Anton Khirnov <anton at khirnov.net> | Sun Jul 20 12:06:47 2014 +0000| [187cfd3c13a1deb47661486824a5b8f41e158a7a] | committer: Diego Biurrun
eamad: use the bytestream2 API instead of AV_RL
This is safer and possibly fixes invalid reads on truncated data.
(cherry-picked from commit 541427ab4d5b4b6f5a90a687a06decdb78e7bc3c)
CC:libav-stable at libav.org
Conflicts:
libavcodec/eamad.c
(cherry picked from commit f9204ec56a4cf73843d1e5b8563d3584c2c05b47)
Signed-off-by: Diego Biurrun <diego at biurrun.de>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=187cfd3c13a1deb47661486824a5b8f41e158a7a
---
libavcodec/eamad.c | 38 +++++++++++++++++++++-----------------
1 file changed, 21 insertions(+), 17 deletions(-)
diff --git a/libavcodec/eamad.c b/libavcodec/eamad.c
index c5aa6ac..0d10982 100644
--- a/libavcodec/eamad.c
+++ b/libavcodec/eamad.c
@@ -29,6 +29,7 @@
*/
#include "avcodec.h"
+#include "bytestream.h"
#include "get_bits.h"
#include "dsputil.h"
#include "aandcttab.h"
@@ -236,29 +237,31 @@ static int decode_frame(AVCodecContext *avctx,
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
- const uint8_t *buf_end = buf+buf_size;
MadContext *t = avctx->priv_data;
+ GetByteContext gb;
MpegEncContext *s = &t->s;
int chunk_type;
int inter;
- if (buf_size < 17) {
- av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
- *data_size = 0;
- return -1;
- }
+ bytestream2_init(&gb, buf, buf_size);
- chunk_type = AV_RL32(&buf[0]);
+ chunk_type = bytestream2_get_le32(&gb);
inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
- buf += 8;
+ bytestream2_skip(&gb, 10);
av_reduce(&avctx->time_base.num, &avctx->time_base.den,
- AV_RL16(&buf[6]), 1000, 1<<30);
+ bytestream2_get_le16(&gb), 1000, 1<<30);
+
+ s->width = bytestream2_get_le16(&gb);
+ s->height = bytestream2_get_le16(&gb);
+ bytestream2_skip(&gb, 1);
+ calc_intra_matrix(t, bytestream2_get_byte(&gb));
+ bytestream2_skip(&gb, 2);
- s->width = AV_RL16(&buf[8]);
- s->height = AV_RL16(&buf[10]);
- calc_intra_matrix(t, buf[13]);
- buf += 16;
+ if (bytestream2_get_bytes_left(&gb) < 2) {
+ av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
+ return AVERROR_INVALIDDATA;
+ }
if (avctx->width != s->width || avctx->height != s->height) {
if (av_image_check_size(s->width, s->height, 0, avctx) < 0)
@@ -276,12 +279,13 @@ static int decode_frame(AVCodecContext *avctx,
}
}
- av_fast_malloc(&t->bitstream_buf, &t->bitstream_buf_size, (buf_end-buf) + FF_INPUT_BUFFER_PADDING_SIZE);
+ av_fast_malloc(&t->bitstream_buf, &t->bitstream_buf_size,
+ bytestream2_get_bytes_left(&gb) + FF_INPUT_BUFFER_PADDING_SIZE);
if (!t->bitstream_buf)
return AVERROR(ENOMEM);
- bswap16_buf(t->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
- init_get_bits(&s->gb, t->bitstream_buf, 8*(buf_end-buf));
-
+ bswap16_buf(t->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
+ bytestream2_get_bytes_left(&gb) / 2);
+ init_get_bits(&s->gb, t->bitstream_buf, 8*(bytestream2_get_bytes_left(&gb)));
for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
decode_mb(t, inter);
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