mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-23 12:43:46 +02:00
vmd: fix segfaults on corruped streams
Signed-off-by: Janne Grunau <janne-libav@jannau.net>
This commit is contained in:
parent
3a742470a8
commit
c0cbe36b18
@ -72,9 +72,11 @@ typedef struct VmdVideoContext {
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#define QUEUE_SIZE 0x1000
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#define QUEUE_MASK 0x0FFF
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static void lz_unpack(const unsigned char *src, unsigned char *dest, int dest_len)
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static void lz_unpack(const unsigned char *src, int src_len,
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unsigned char *dest, int dest_len)
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{
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const unsigned char *s;
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unsigned int s_len;
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unsigned char *d;
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unsigned char *d_end;
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unsigned char queue[QUEUE_SIZE];
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@ -87,13 +89,16 @@ static void lz_unpack(const unsigned char *src, unsigned char *dest, int dest_le
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unsigned int i, j;
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s = src;
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s_len = src_len;
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d = dest;
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d_end = d + dest_len;
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dataleft = AV_RL32(s);
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s += 4;
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s += 4; s_len -= 4;
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memset(queue, 0x20, QUEUE_SIZE);
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if (s_len < 4)
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return;
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if (AV_RL32(s) == 0x56781234) {
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s += 4;
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s += 4; s_len -= 4;
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qpos = 0x111;
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speclen = 0xF + 3;
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} else {
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@ -101,32 +106,41 @@ static void lz_unpack(const unsigned char *src, unsigned char *dest, int dest_le
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speclen = 100; /* no speclen */
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}
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while (dataleft > 0) {
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tag = *s++;
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while (dataleft > 0 && s_len > 0) {
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tag = *s++; s_len--;
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if ((tag == 0xFF) && (dataleft > 8)) {
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if (d + 8 > d_end)
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if (d + 8 > d_end || s_len < 8)
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return;
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for (i = 0; i < 8; i++) {
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queue[qpos++] = *d++ = *s++;
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qpos &= QUEUE_MASK;
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}
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s_len -= 8;
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dataleft -= 8;
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} else {
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for (i = 0; i < 8; i++) {
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if (dataleft == 0)
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break;
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if (tag & 0x01) {
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if (d + 1 > d_end)
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if (d + 1 > d_end || s_len < 1)
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return;
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queue[qpos++] = *d++ = *s++;
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qpos &= QUEUE_MASK;
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dataleft--;
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s_len--;
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} else {
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if (s_len < 2)
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return;
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chainofs = *s++;
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chainofs |= ((*s & 0xF0) << 4);
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chainlen = (*s++ & 0x0F) + 3;
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if (chainlen == speclen)
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s_len -= 2;
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if (chainlen == speclen) {
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if (s_len < 1)
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return;
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chainlen = *s++ + 0xF + 3;
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s_len--;
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}
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if (d + chainlen > d_end)
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return;
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for (j = 0; j < chainlen; j++) {
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@ -143,7 +157,7 @@ static void lz_unpack(const unsigned char *src, unsigned char *dest, int dest_le
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}
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static int rle_unpack(const unsigned char *src, unsigned char *dest,
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int src_len, int dest_len)
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int src_count, int src_size, int dest_len)
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{
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const unsigned char *ps;
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unsigned char *pd;
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@ -152,31 +166,40 @@ static int rle_unpack(const unsigned char *src, unsigned char *dest,
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ps = src;
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pd = dest;
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if (src_len & 1)
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if (src_count & 1) {
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if (src_size < 1)
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return 0;
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*pd++ = *ps++;
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src_size--;
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}
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src_len >>= 1;
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src_count >>= 1;
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i = 0;
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do {
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if (src_size < 1)
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break;
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l = *ps++;
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src_size--;
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if (l & 0x80) {
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l = (l & 0x7F) * 2;
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if (pd + l > dest_end)
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if (pd + l > dest_end || src_size < l)
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return ps - src;
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memcpy(pd, ps, l);
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ps += l;
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src_size -= l;
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pd += l;
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} else {
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if (pd + i > dest_end)
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if (pd + i > dest_end || src_size < 2)
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return ps - src;
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for (i = 0; i < l; i++) {
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*pd++ = ps[0];
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*pd++ = ps[1];
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}
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ps += 2;
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src_size -= 2;
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}
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i += l;
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} while (i < src_len);
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} while (i < src_count);
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return ps - src;
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}
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@ -191,6 +214,7 @@ static void vmd_decode(VmdVideoContext *s)
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const unsigned char *p = s->buf + 16;
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const unsigned char *pb;
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unsigned int pb_size;
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unsigned char meth;
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unsigned char *dp; /* pointer to current frame */
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unsigned char *pp; /* pointer to previous frame */
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@ -204,6 +228,16 @@ static void vmd_decode(VmdVideoContext *s)
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frame_y = AV_RL16(&s->buf[8]);
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frame_width = AV_RL16(&s->buf[10]) - frame_x + 1;
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frame_height = AV_RL16(&s->buf[12]) - frame_y + 1;
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if (frame_x < 0 || frame_width < 0 ||
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frame_x >= s->avctx->width ||
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frame_width > s->avctx->width ||
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frame_x + frame_width > s->avctx->width)
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return;
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if (frame_y < 0 || frame_height < 0 ||
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frame_y >= s->avctx->height ||
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frame_height > s->avctx->height ||
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frame_y + frame_height > s->avctx->height)
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return;
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if ((frame_width == s->avctx->width && frame_height == s->avctx->height) &&
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(frame_x || frame_y)) {
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@ -216,8 +250,9 @@ static void vmd_decode(VmdVideoContext *s)
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/* if only a certain region will be updated, copy the entire previous
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* frame before the decode */
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if (frame_x || frame_y || (frame_width != s->avctx->width) ||
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(frame_height != s->avctx->height)) {
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if (s->prev_frame.data[0] &&
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(frame_x || frame_y || (frame_width != s->avctx->width) ||
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(frame_height != s->avctx->height))) {
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memcpy(s->frame.data[0], s->prev_frame.data[0],
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s->avctx->height * s->frame.linesize[0]);
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@ -235,14 +270,19 @@ static void vmd_decode(VmdVideoContext *s)
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}
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s->size -= (256 * 3 + 2);
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}
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if (s->size >= 0) {
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if (s->size > 0) {
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/* originally UnpackFrame in VAG's code */
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pb = p;
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meth = *pb++;
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pb_size = s->buf + s->size - pb;
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if (pb_size < 1)
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return;
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meth = *pb++; pb_size--;
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if (meth & 0x80) {
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lz_unpack(pb, s->unpack_buffer, s->unpack_buffer_size);
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lz_unpack(pb, pb_size,
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s->unpack_buffer, s->unpack_buffer_size);
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meth &= 0x7F;
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pb = s->unpack_buffer;
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pb_size = s->unpack_buffer_size;
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}
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dp = &s->frame.data[0][frame_y * s->frame.linesize[0] + frame_x];
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@ -252,17 +292,21 @@ static void vmd_decode(VmdVideoContext *s)
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for (i = 0; i < frame_height; i++) {
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ofs = 0;
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do {
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if (pb_size < 1)
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return;
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len = *pb++;
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pb_size--;
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if (len & 0x80) {
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len = (len & 0x7F) + 1;
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if (ofs + len > frame_width)
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if (ofs + len > frame_width || pb_size < len)
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return;
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memcpy(&dp[ofs], pb, len);
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pb += len;
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pb_size -= len;
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ofs += len;
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} else {
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/* interframe pixel copy */
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if (ofs + len + 1 > frame_width)
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if (ofs + len + 1 > frame_width || !s->prev_frame.data[0])
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return;
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memcpy(&dp[ofs], &pp[ofs], len + 1);
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ofs += len + 1;
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@ -280,8 +324,11 @@ static void vmd_decode(VmdVideoContext *s)
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case 2:
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for (i = 0; i < frame_height; i++) {
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if (pb_size < frame_width)
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return;
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memcpy(dp, pb, frame_width);
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pb += frame_width;
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pb_size -= frame_width;
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dp += s->frame.linesize[0];
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pp += s->prev_frame.linesize[0];
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}
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@ -291,18 +338,27 @@ static void vmd_decode(VmdVideoContext *s)
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for (i = 0; i < frame_height; i++) {
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ofs = 0;
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do {
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if (pb_size < 1)
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return;
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len = *pb++;
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pb_size--;
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if (len & 0x80) {
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len = (len & 0x7F) + 1;
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if (pb_size < 1)
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return;
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if (*pb++ == 0xFF)
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len = rle_unpack(pb, &dp[ofs], len, frame_width - ofs);
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else
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len = rle_unpack(pb, &dp[ofs], len, pb_size, frame_width - ofs);
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else {
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if (pb_size < len)
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return;
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memcpy(&dp[ofs], pb, len);
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}
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pb += len;
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pb_size -= 1 + len;
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ofs += len;
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} else {
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/* interframe pixel copy */
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if (ofs + len + 1 > frame_width)
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if (ofs + len + 1 > frame_width || !s->prev_frame.data[0])
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return;
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memcpy(&dp[ofs], &pp[ofs], len + 1);
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ofs += len + 1;
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