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Merge commit '30db94dc399f6e4ef8905049d9b740556f0fce47' 

* commit '30db94dc399f6e4ef8905049d9b740556f0fce47':
  xan: Use bytestream2 to limit reading to within the buffer

Conflicts:
	libavcodec/xan.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2013-09-30 01:09:38 +02:00
parent a612bb3099 30db94dc39
commit b6dfb82913
1 changed files with 15 additions and 17 deletions
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32
libavcodec/xan.c
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@ -300,10 +300,9 @@ static int xan_wc3_decode_frame(XanContext *s, AVFrame *frame)
/* pointers to segments inside the compressed chunk */
const uint8_t *huffman_segment;
const uint8_t *size_segment;
const uint8_t *vector_segment;
GetByteContext size_segment;
GetByteContext vector_segment;
const uint8_t *imagedata_segment;
const uint8_t *buf_end = s->buf + s->size;
int huffman_offset, size_offset, vector_offset, imagedata_offset,
imagedata_size;
@ -322,8 +321,8 @@ static int xan_wc3_decode_frame(XanContext *s, AVFrame *frame)
return AVERROR_INVALIDDATA;
huffman_segment = s->buf + huffman_offset;
size_segment = s->buf + size_offset;
vector_segment = s->buf + vector_offset;
bytestream2_init(&size_segment, s->buf + size_offset, s->size - size_offset);
bytestream2_init(&vector_segment, s->buf + vector_offset, s->size - vector_offset);
imagedata_segment = s->buf + imagedata_offset;
if (xan_huffman_decode(opcode_buffer, opcode_buffer_size,
@ -375,31 +374,29 @@ static int xan_wc3_decode_frame(XanContext *s, AVFrame *frame)
case 9:
case 19:
if (buf_end - size_segment < 1) {
if (bytestream2_get_bytes_left(&size_segment) < 1) {
av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
return AVERROR_INVALIDDATA;
}
size = *size_segment++;
size = bytestream2_get_byte(&size_segment);
break;
case 10:
case 20:
if (buf_end - size_segment < 2) {
if (bytestream2_get_bytes_left(&size_segment) < 2) {
av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
return AVERROR_INVALIDDATA;
}
size = AV_RB16(&size_segment[0]);
size_segment += 2;
size = bytestream2_get_be16(&size_segment);
break;
case 11:
case 21:
if (buf_end - size_segment < 3) {
if (bytestream2_get_bytes_left(&size_segment) < 3) {
av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
return AVERROR_INVALIDDATA;
}
size = AV_RB24(size_segment);
size_segment += 3;
size = bytestream2_get_be24(&size_segment);
break;
}
@ -420,14 +417,15 @@ static int xan_wc3_decode_frame(XanContext *s, AVFrame *frame)
imagedata_size -= size;
}
} else {
if (vector_segment >= buf_end) {
uint8_t vector;
if (bytestream2_get_bytes_left(&vector_segment) <= 0) {
av_log(s->avctx, AV_LOG_ERROR, "vector_segment overread\n");
return AVERROR_INVALIDDATA;
}
/* run-based motion compensation from last frame */
motion_x = sign_extend(*vector_segment >> 4, 4);
motion_y = sign_extend(*vector_segment & 0xF, 4);
vector_segment++;
vector = bytestream2_get_byte(&vector_segment);
motion_x = sign_extend(vector >> 4, 4);
motion_y = sign_extend(vector & 0xF, 4);
/* copy a run of pixels from the previous frame */
xan_wc3_copy_pixel_run(s, frame, x, y, size, motion_x, motion_y);