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ffmpeg/libavcodec/cinepak.c
Laurent Aimar d239d4b447 cinepak: Fix invalid read access on extra data 
Signed-off-by: Janne Grunau <janne-libav@jannau.net>
2011-10-06 23:35:29 +02:00

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/*
* Cinepak Video Decoder
* Copyright (C) 2003 the ffmpeg project
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Cinepak video decoder
* by Ewald Snel <ewald@rambo.its.tudelft.nl>
* For more information on the Cinepak algorithm, visit:
* http://www.csse.monash.edu.au/~timf/
* For more information on the quirky data inside Sega FILM/CPK files, visit:
* http://wiki.multimedia.cx/index.php?title=Sega_FILM
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
typedef struct {
uint8_t y0, y1, y2, y3;
uint8_t u, v;
} cvid_codebook;
#define MAX_STRIPS 32
typedef struct {
uint16_t id;
uint16_t x1, y1;
uint16_t x2, y2;
cvid_codebook v4_codebook[256];
cvid_codebook v1_codebook[256];
} cvid_strip;
typedef struct CinepakContext {
AVCodecContext *avctx;
AVFrame frame;
const unsigned char *data;
int size;
int width, height;
int palette_video;
cvid_strip strips[MAX_STRIPS];
int sega_film_skip_bytes;
uint32_t pal[256];
} CinepakContext;
static void cinepak_decode_codebook (cvid_codebook *codebook,
int chunk_id, int size, const uint8_t *data)
{
const uint8_t *eod = (data + size);
uint32_t flag, mask;
int i, n;
/* check if this chunk contains 4- or 6-element vectors */
n = (chunk_id & 0x04) ? 4 : 6;
flag = 0;
mask = 0;
for (i=0; i < 256; i++) {
if ((chunk_id & 0x01) && !(mask >>= 1)) {
if ((data + 4) > eod)
break;
flag = AV_RB32 (data);
data += 4;
mask = 0x80000000;
}
if (!(chunk_id & 0x01) || (flag & mask)) {
if ((data + n) > eod)
break;
if (n == 6) {
codebook[i].y0 = *data++;
codebook[i].y1 = *data++;
codebook[i].y2 = *data++;
codebook[i].y3 = *data++;
codebook[i].u = 128 + *data++;
codebook[i].v = 128 + *data++;
} else {
/* this codebook type indicates either greyscale or
* palettized video; if palettized, U & V components will
* not be used so it is safe to set them to 128 for the
* benefit of greyscale rendering in YUV420P */
codebook[i].y0 = *data++;
codebook[i].y1 = *data++;
codebook[i].y2 = *data++;
codebook[i].y3 = *data++;
codebook[i].u = 128;
codebook[i].v = 128;
}
}
}
}
static int cinepak_decode_vectors (CinepakContext *s, cvid_strip *strip,
int chunk_id, int size, const uint8_t *data)
{
const uint8_t *eod = (data + size);
uint32_t flag, mask;
cvid_codebook *codebook;
unsigned int x, y;
uint32_t iy[4];
uint32_t iu[2];
uint32_t iv[2];
flag = 0;
mask = 0;
for (y=strip->y1; y < strip->y2; y+=4) {
iy[0] = strip->x1 + (y * s->frame.linesize[0]);
iy[1] = iy[0] + s->frame.linesize[0];
iy[2] = iy[1] + s->frame.linesize[0];
iy[3] = iy[2] + s->frame.linesize[0];
iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]);
iu[1] = iu[0] + s->frame.linesize[1];
iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]);
iv[1] = iv[0] + s->frame.linesize[2];
for (x=strip->x1; x < strip->x2; x+=4) {
if ((chunk_id & 0x01) && !(mask >>= 1)) {
if ((data + 4) > eod)
return -1;
flag = AV_RB32 (data);
data += 4;
mask = 0x80000000;
}
if (!(chunk_id & 0x01) || (flag & mask)) {
if (!(chunk_id & 0x02) && !(mask >>= 1)) {
if ((data + 4) > eod)
return -1;
flag = AV_RB32 (data);
data += 4;
mask = 0x80000000;
}
if ((chunk_id & 0x02) || (~flag & mask)) {
if (data >= eod)
return -1;
codebook = &strip->v1_codebook[*data++];
s->frame.data[0][iy[0] + 0] = codebook->y0;
s->frame.data[0][iy[0] + 1] = codebook->y0;
s->frame.data[0][iy[1] + 0] = codebook->y0;
s->frame.data[0][iy[1] + 1] = codebook->y0;
if (!s->palette_video) {
s->frame.data[1][iu[0]] = codebook->u;
s->frame.data[2][iv[0]] = codebook->v;
}
s->frame.data[0][iy[0] + 2] = codebook->y1;
s->frame.data[0][iy[0] + 3] = codebook->y1;
s->frame.data[0][iy[1] + 2] = codebook->y1;
s->frame.data[0][iy[1] + 3] = codebook->y1;
if (!s->palette_video) {
s->frame.data[1][iu[0] + 1] = codebook->u;
s->frame.data[2][iv[0] + 1] = codebook->v;
}
s->frame.data[0][iy[2] + 0] = codebook->y2;
s->frame.data[0][iy[2] + 1] = codebook->y2;
s->frame.data[0][iy[3] + 0] = codebook->y2;
s->frame.data[0][iy[3] + 1] = codebook->y2;
if (!s->palette_video) {
s->frame.data[1][iu[1]] = codebook->u;
s->frame.data[2][iv[1]] = codebook->v;
}
s->frame.data[0][iy[2] + 2] = codebook->y3;
s->frame.data[0][iy[2] + 3] = codebook->y3;
s->frame.data[0][iy[3] + 2] = codebook->y3;
s->frame.data[0][iy[3] + 3] = codebook->y3;
if (!s->palette_video) {
s->frame.data[1][iu[1] + 1] = codebook->u;
s->frame.data[2][iv[1] + 1] = codebook->v;
}
} else if (flag & mask) {
if ((data + 4) > eod)
return -1;
codebook = &strip->v4_codebook[*data++];
s->frame.data[0][iy[0] + 0] = codebook->y0;
s->frame.data[0][iy[0] + 1] = codebook->y1;
s->frame.data[0][iy[1] + 0] = codebook->y2;
s->frame.data[0][iy[1] + 1] = codebook->y3;
if (!s->palette_video) {
s->frame.data[1][iu[0]] = codebook->u;
s->frame.data[2][iv[0]] = codebook->v;
}
codebook = &strip->v4_codebook[*data++];
s->frame.data[0][iy[0] + 2] = codebook->y0;
s->frame.data[0][iy[0] + 3] = codebook->y1;
s->frame.data[0][iy[1] + 2] = codebook->y2;
s->frame.data[0][iy[1] + 3] = codebook->y3;
if (!s->palette_video) {
s->frame.data[1][iu[0] + 1] = codebook->u;
s->frame.data[2][iv[0] + 1] = codebook->v;
}
codebook = &strip->v4_codebook[*data++];
s->frame.data[0][iy[2] + 0] = codebook->y0;
s->frame.data[0][iy[2] + 1] = codebook->y1;
s->frame.data[0][iy[3] + 0] = codebook->y2;
s->frame.data[0][iy[3] + 1] = codebook->y3;
if (!s->palette_video) {
s->frame.data[1][iu[1]] = codebook->u;
s->frame.data[2][iv[1]] = codebook->v;
}
codebook = &strip->v4_codebook[*data++];
s->frame.data[0][iy[2] + 2] = codebook->y0;
s->frame.data[0][iy[2] + 3] = codebook->y1;
s->frame.data[0][iy[3] + 2] = codebook->y2;
s->frame.data[0][iy[3] + 3] = codebook->y3;
if (!s->palette_video) {
s->frame.data[1][iu[1] + 1] = codebook->u;
s->frame.data[2][iv[1] + 1] = codebook->v;
}
}
}
iy[0] += 4; iy[1] += 4;
iy[2] += 4; iy[3] += 4;
iu[0] += 2; iu[1] += 2;
iv[0] += 2; iv[1] += 2;
}
}
return 0;
}
static int cinepak_decode_strip (CinepakContext *s,
cvid_strip *strip, const uint8_t *data, int size)
{
const uint8_t *eod = (data + size);
int chunk_id, chunk_size;
/* coordinate sanity checks */
if (strip->x1 >= s->width || strip->x2 > s->width ||
strip->y1 >= s->height || strip->y2 > s->height ||
strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
return -1;
while ((data + 4) <= eod) {
chunk_id = data[0];
chunk_size = AV_RB24 (&data[1]) - 4;
if(chunk_size < 0)
return -1;
data += 4;
chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
switch (chunk_id) {
case 0x20:
case 0x21:
case 0x24:
case 0x25:
cinepak_decode_codebook (strip->v4_codebook, chunk_id,
chunk_size, data);
break;
case 0x22:
case 0x23:
case 0x26:
case 0x27:
cinepak_decode_codebook (strip->v1_codebook, chunk_id,
chunk_size, data);
break;
case 0x30:
case 0x31:
case 0x32:
return cinepak_decode_vectors (s, strip, chunk_id,
chunk_size, data);
}
data += chunk_size;
}
return -1;
}
static int cinepak_decode (CinepakContext *s)
{
const uint8_t *eod = (s->data + s->size);
int i, result, strip_size, frame_flags, num_strips;
int y0 = 0;
int encoded_buf_size;
if (s->size < 10)
return -1;
frame_flags = s->data[0];
num_strips = AV_RB16 (&s->data[8]);
encoded_buf_size = ((s->data[1] << 16) | AV_RB16 (&s->data[2]));
/* if this is the first frame, check for deviant Sega FILM data */
if (s->sega_film_skip_bytes == -1) {
if (encoded_buf_size != s->size) {
/* If the encoded frame size differs from the frame size as indicated
* by the container file, this data likely comes from a Sega FILM/CPK file.
* If the frame header is followed by the bytes FE 00 00 06 00 00 then
* this is probably one of the two known files that have 6 extra bytes
* after the frame header. Else, assume 2 extra bytes. */
if (s->size >= 16 &&
(s->data[10] == 0xFE) &&
(s->data[11] == 0x00) &&
(s->data[12] == 0x00) &&
(s->data[13] == 0x06) &&
(s->data[14] == 0x00) &&
(s->data[15] == 0x00))
s->sega_film_skip_bytes = 6;
else
s->sega_film_skip_bytes = 2;
} else
s->sega_film_skip_bytes = 0;
}
s->data += 10 + s->sega_film_skip_bytes;
if (num_strips > MAX_STRIPS)
num_strips = MAX_STRIPS;
for (i=0; i < num_strips; i++) {
if ((s->data + 12) > eod)
return -1;
s->strips[i].id = s->data[0];
s->strips[i].y1 = y0;
s->strips[i].x1 = 0;
s->strips[i].y2 = y0 + AV_RB16 (&s->data[8]);
s->strips[i].x2 = s->avctx->width;
strip_size = AV_RB24 (&s->data[1]) - 12;
s->data += 12;
strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
if ((i > 0) && !(frame_flags & 0x01)) {
memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
sizeof(s->strips[i].v4_codebook));
memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
sizeof(s->strips[i].v1_codebook));
}
result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
if (result != 0)
return result;
s->data += strip_size;
y0 = s->strips[i].y2;
}
return 0;
}
static av_cold int cinepak_decode_init(AVCodecContext *avctx)
{
CinepakContext *s = avctx->priv_data;
s->avctx = avctx;
s->width = (avctx->width + 3) & ~3;
s->height = (avctx->height + 3) & ~3;
s->sega_film_skip_bytes = -1; /* uninitialized state */
// check for paletted data
if (avctx->bits_per_coded_sample != 8) {
s->palette_video = 0;
avctx->pix_fmt = PIX_FMT_YUV420P;
} else {
s->palette_video = 1;
avctx->pix_fmt = PIX_FMT_PAL8;
}
s->frame.data[0] = NULL;
return 0;
}
static int cinepak_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
CinepakContext *s = avctx->priv_data;
s->data = buf;
s->size = buf_size;
s->frame.reference = 1;
s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
FF_BUFFER_HINTS_REUSABLE;
if (avctx->reget_buffer(avctx, &s->frame)) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
if (s->palette_video) {
const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
if (pal) {
s->frame.palette_has_changed = 1;
memcpy(s->pal, pal, AVPALETTE_SIZE);
}
}
cinepak_decode(s);
if (s->palette_video)
memcpy (s->frame.data[1], s->pal, AVPALETTE_SIZE);
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
/* report that the buffer was completely consumed */
return buf_size;
}
static av_cold int cinepak_decode_end(AVCodecContext *avctx)
{
CinepakContext *s = avctx->priv_data;
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
return 0;
}
AVCodec ff_cinepak_decoder = {
.name = "cinepak",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_CINEPAK,
.priv_data_size = sizeof(CinepakContext),
.init = cinepak_decode_init,
.close = cinepak_decode_end,
.decode = cinepak_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Cinepak"),
};
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