On Sat, Feb 16, 2013 at 07:56:01PM +0100, Alexandra Khirnova wrote:
> ---
> libavcodec/vmdav.c | 143
> +++++++++++++++++++---------------------------------
> 1 file changed, 53 insertions(+), 90 deletions(-)
>
> diff --git a/libavcodec/vmdav.c b/libavcodec/vmdav.c
> index cffc00a..41fe7f3 100644
> --- a/libavcodec/vmdav.c
> +++ b/libavcodec/vmdav.c
> @@ -48,6 +48,7 @@
> #include "libavutil/intreadwrite.h"
> #include "avcodec.h"
> #include "internal.h"
> +#include "bytestream.h"
>
> #define VMD_HEADER_SIZE 0x330
> #define PALETTE_COUNT 256
> @@ -78,8 +79,6 @@ typedef struct VmdVideoContext {
> static void lz_unpack(const unsigned char *src, int src_len,
> unsigned char *dest, int dest_len)
> {
> - const unsigned char *s;
> - unsigned int s_len;
> unsigned char *d;
> unsigned char *d_end;
> unsigned char queue[QUEUE_SIZE];
> @@ -90,18 +89,17 @@ static void lz_unpack(const unsigned char *src, int
> src_len,
> unsigned int speclen;
> unsigned char tag;
> unsigned int i, j;
> + GetByteContext gb;
>
> - s = src;
> - s_len = src_len;
> + bytestream2_init(&gb, src, src_len);
> d = dest;
> d_end = d + dest_len;
> - dataleft = AV_RL32(s);
> - s += 4; s_len -= 4;
> + dataleft = bytestream2_get_le32(&gb);
> memset(queue, 0x20, QUEUE_SIZE);
> - if (s_len < 4)
> + if (bytestream2_get_bytes_left(&gb) < 4)
> return;
> - if (AV_RL32(s) == 0x56781234) {
> - s += 4; s_len -= 4;
> + if (bytestream2_peek_le32(&gb) == 0x56781234) {
> + bytestream2_get_le32(&gb);
> qpos = 0x111;
> speclen = 0xF + 3;
> } else {
> @@ -109,40 +107,32 @@ static void lz_unpack(const unsigned char *src, int
> src_len,
> speclen = 100; /* no speclen */
> }
>
> - while (dataleft > 0 && s_len > 0) {
> - tag = *s++; s_len--;
> + while (dataleft > 0 && bytestream2_get_bytes_left(&gb) > 0) {
> + tag = bytestream2_get_byte(&gb);
> if ((tag == 0xFF) && (dataleft > 8)) {
> - if (d + 8 > d_end || s_len < 8)
> + if (d + 8 > d_end || bytestream2_get_bytes_left(&gb) < 8)
> return;
> for (i = 0; i < 8; i++) {
> - queue[qpos++] = *d++ = *s++;
> + queue[qpos++] = *d++ = bytestream2_get_byte(&gb);
> qpos &= QUEUE_MASK;
> }
> - s_len -= 8;
> dataleft -= 8;
> } else {
> for (i = 0; i < 8; i++) {
> if (dataleft == 0)
> break;
> if (tag & 0x01) {
> - if (d + 1 > d_end || s_len < 1)
> + if (d + 1 > d_end || bytestream2_get_bytes_left(&gb) < 1)
> return;
> - queue[qpos++] = *d++ = *s++;
> + queue[qpos++] = *d++ = bytestream2_get_byte(&gb);
> qpos &= QUEUE_MASK;
> dataleft--;
> - s_len--;
> } else {
> - if (s_len < 2)
> - return;
> - chainofs = *s++;
> - chainofs |= ((*s & 0xF0) << 4);
> - chainlen = (*s++ & 0x0F) + 3;
> - s_len -= 2;
> + chainofs = bytestream2_get_byte(&gb);
> + chainofs |= ((bytestream2_peek_le32(&gb) & 0xF0) << 4);
> + chainlen = (bytestream2_get_byte(&gb) & 0x0F) + 3;
> if (chainlen == speclen) {
> - if (s_len < 1)
> - return;
> - chainlen = *s++ + 0xF + 3;
> - s_len--;
> + chainlen = bytestream2_get_byte(&gb) + 0xF + 3;
> }
> if (d + chainlen > d_end)
> return;
> @@ -162,49 +152,44 @@ static void lz_unpack(const unsigned char *src, int
> src_len,
> static int rle_unpack(const unsigned char *src, unsigned char *dest,
> int src_count, int src_size, int dest_len)
> {
> - const unsigned char *ps;
> unsigned char *pd;
> int i, l;
> unsigned char *dest_end = dest + dest_len;
> + GetByteContext gb;
>
> - ps = src;
> + bytestream2_init(&gb, src, src_size);
> pd = dest;
> if (src_count & 1) {
> - if (src_size < 1)
> + if (bytestream2_get_bytes_left(&gb) < 1)
> return 0;
> - *pd++ = *ps++;
> - src_size--;
> + *pd++ = bytestream2_get_byte(&gb);
> }
>
> src_count >>= 1;
> i = 0;
> do {
> - if (src_size < 1)
> + if (bytestream2_get_bytes_left(&gb) < 1)
> break;
> - l = *ps++;
> - src_size--;
> + l = bytestream2_get_byte(&gb);
> if (l & 0x80) {
> l = (l & 0x7F) * 2;
> - if (pd + l > dest_end || src_size < l)
> - return ps - src;
> - memcpy(pd, ps, l);
> - ps += l;
> - src_size -= l;
> + if (pd + l > dest_end || bytestream2_get_bytes_left(&gb) < l)
> + return bytestream2_tell(&gb);
> + bytestream2_get_buffer(&gb, pd, l);
> pd += l;
> } else {
> - if (pd + i > dest_end || src_size < 2)
> - return ps - src;
> + if (pd + i > dest_end || bytestream2_get_bytes_left(&gb) < 2)
> + return bytestream2_get_buffer(&gb, pd, l);
> for (i = 0; i < l; i++) {
> - *pd++ = ps[0];
> - *pd++ = ps[1];
> + *pd++ = bytestream2_get_byte(&gb);
> + *pd++ = bytestream2_get_byte(&gb);
> }
> - ps += 2;
> - src_size -= 2;
> + bytestream2_skip(&gb, 2);
> }
> i += l;
> } while (i < src_count);
>
> - return ps - src;
> + return bytestream2_tell(&gb);
> }
>
> static void vmd_decode(VmdVideoContext *s)
> @@ -213,11 +198,8 @@ static void vmd_decode(VmdVideoContext *s)
> unsigned int *palette32;
> unsigned char r, g, b;
>
> - /* point to the start of the encoded data */
> - const unsigned char *p = s->buf + 16;
> + GetByteContext gb;
>
> - const unsigned char *pb;
> - unsigned int pb_size;
> unsigned char meth;
> unsigned char *dp; /* pointer to current frame */
> unsigned char *pp; /* pointer to previous frame */
> @@ -262,30 +244,29 @@ static void vmd_decode(VmdVideoContext *s)
> }
>
> /* check if there is a new palette */
> + bytestream2_init(&gb, s->buf + 16, s->size - 16);
> if (s->buf[15] & 0x02) {
> - p += 2;
> + bytestream2_skip(&gb, 2);
> palette32 = (unsigned int *)s->palette;
> for (i = 0; i < PALETTE_COUNT; i++) {
> - r = *p++ * 4;
> - g = *p++ * 4;
> - b = *p++ * 4;
> + r = bytestream2_get_byte(&gb) * 4;
> + g = bytestream2_get_byte(&gb) * 4;
> + b = bytestream2_get_byte(&gb) * 4;
here one could just add a check above that there's enough data for the palette
and use bytestream2_get_byteu() in the loop
> palette32[i] = (r << 16) | (g << 8) | (b);
> }
> s->size -= (256 * 3 + 2);
> }
> if (s->size > 0) {
> /* originally UnpackFrame in VAG's code */
> - pb = p;
> - pb_size = s->buf + s->size - pb;
> - if (pb_size < 1)
> + bytestream2_init(&gb, gb.buffer, s->buf + s->size - gb.buffer);
> + if (bytestream2_get_bytes_left(&gb) < 1)
> return;
> - meth = *pb++; pb_size--;
> + meth = bytestream2_get_byte(&gb);
> if (meth & 0x80) {
> - lz_unpack(pb, pb_size,
> + lz_unpack(gb.buffer, bytestream2_get_bytes_left(&gb),
> s->unpack_buffer, s->unpack_buffer_size);
> meth &= 0x7F;
> - pb = s->unpack_buffer;
> - pb_size = s->unpack_buffer_size;
> + bytestream2_init(&gb, s->unpack_buffer, s->unpack_buffer_size);
> }
>
> dp = &s->frame.data[0][frame_y * s->frame.linesize[0] + frame_x];
> @@ -295,17 +276,12 @@ static void vmd_decode(VmdVideoContext *s)
> for (i = 0; i < frame_height; i++) {
> ofs = 0;
> do {
> - if (pb_size < 1)
> - return;
> - len = *pb++;
> - pb_size--;
> + len = bytestream2_get_byteu(&gb);
bytestream2_get_byte() here and below
> if (len & 0x80) {
> len = (len & 0x7F) + 1;
> - if (ofs + len > frame_width || pb_size < len)
> + if (ofs + len > frame_width ||
> bytestream2_get_bytes_left(&gb) < len)
> return;
> - memcpy(&dp[ofs], pb, len);
> - pb += len;
> - pb_size -= len;
> + bytestream2_get_buffer(&gb, &dp[ofs], len);
> ofs += len;
> } else {
> /* interframe pixel copy */
> @@ -327,11 +303,7 @@ static void vmd_decode(VmdVideoContext *s)
>
> case 2:
> for (i = 0; i < frame_height; i++) {
> - if (pb_size < frame_width)
> - return;
> - memcpy(dp, pb, frame_width);
> - pb += frame_width;
> - pb_size -= frame_width;
> + bytestream2_get_buffer(&gb, dp, frame_width);
> dp += s->frame.linesize[0];
> pp += s->prev_frame.linesize[0];
> }
> @@ -341,23 +313,14 @@ static void vmd_decode(VmdVideoContext *s)
> for (i = 0; i < frame_height; i++) {
> ofs = 0;
> do {
> - if (pb_size < 1)
> - return;
> - len = *pb++;
> - pb_size--;
> + len = bytestream2_get_byteu(&gb);
> if (len & 0x80) {
> len = (len & 0x7F) + 1;
> - if (pb_size < 1)
> - return;
> - if (*pb++ == 0xFF)
> - len = rle_unpack(pb, &dp[ofs], len, pb_size,
> frame_width - ofs);
> - else {
> - if (pb_size < len)
> - return;
> - memcpy(&dp[ofs], pb, len);
> - }
> - pb += len;
> - pb_size -= 1 + len;
> + if (bytestream2_get_byteu(&gb) == 0xFF)
> + len = rle_unpack(gb.buffer, &dp[ofs],
> len,bytestream2_get_bytes_left(&gb), frame_width - ofs);
this line should be broken, it's too long
> + else
> + memcpy(&dp[ofs], gb.buffer, len);
> + bytestream2_skip(&gb, len);
> ofs += len;
> } else {
> /* interframe pixel copy */
> --
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