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ffmpeg/libavcodec/cinepak.c

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/*
* Cinepak Video Decoder
* Copyright (C) 2003 the ffmpeg project
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/**
* @file cinepak.c
* 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/
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "common.h"
#include "avcodec.h"
#include "dsputil.h"
#define PALETTE_COUNT 256
typedef struct {
uint8_t y0, y1, y2, y3;
uint8_t u, v;
} cvid_codebook_t;
#define MAX_STRIPS 32
typedef struct {
uint16_t id;
uint16_t x1, y1;
uint16_t x2, y2;
cvid_codebook_t v4_codebook[256];
cvid_codebook_t v1_codebook[256];
} cvid_strip_t;
typedef struct CinepakContext {
AVCodecContext *avctx;
DSPContext dsp;
AVFrame frame;
AVFrame prev_frame;
unsigned char *data;
int size;
int width, height;
unsigned char palette[PALETTE_COUNT * 4];
int palette_video;
cvid_strip_t strips[MAX_STRIPS];
} CinepakContext;
static void cinepak_decode_codebook (cvid_codebook_t *codebook,
int chunk_id, int size, uint8_t *data)
{
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 & 0x0400) ? 4 : 6;
flag = 0;
mask = 0;
for (i=0; i < 256; i++) {
if ((chunk_id & 0x0100) && !(mask >>= 1)) {
if ((data + 4) > eod)
break;
flag = BE_32 (data);
data += 4;
mask = 0x80000000;
}
if (!(chunk_id & 0x0100) || (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_t *strip,
int chunk_id, int size, uint8_t *data)
{
uint8_t *eod = (data + size);
uint32_t flag, mask;
cvid_codebook_t *codebook;
unsigned int i, j, 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 & 0x0100) && !(mask >>= 1)) {
if ((data + 4) > eod)
return -1;
flag = BE_32 (data);
data += 4;
mask = 0x80000000;
}
if (!(chunk_id & 0x0100) || (flag & mask)) {
if (!(chunk_id & 0x0200) && !(mask >>= 1)) {
if ((data + 4) > eod)
return -1;
flag = BE_32 (data);
data += 4;
mask = 0x80000000;
}
if ((chunk_id & 0x0200) || (~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->y0;
s->frame.data[0][iy[0] + 3] = codebook->y0;
s->frame.data[0][iy[1] + 2] = codebook->y0;
s->frame.data[0][iy[1] + 3] = codebook->y0;
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->y0;
s->frame.data[0][iy[2] + 1] = codebook->y0;
s->frame.data[0][iy[3] + 0] = codebook->y0;
s->frame.data[0][iy[3] + 1] = codebook->y0;
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->y0;
s->frame.data[0][iy[2] + 3] = codebook->y0;
s->frame.data[0][iy[3] + 2] = codebook->y0;
s->frame.data[0][iy[3] + 3] = codebook->y0;
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;
}
}
} else {
/* copy from the previous frame */
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
s->frame.data[0][iy[i] + j] =
s->prev_frame.data[0][iy[i] + j];
}
}
for (i = 0; i < 2; i++) {
for (j = 0; j < 2; j++) {
s->frame.data[1][iu[i] + j] =
s->prev_frame.data[1][iu[i] + j];
s->frame.data[2][iv[i] + j] =
s->prev_frame.data[2][iv[i] + j];
}
}
}
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_t *strip, uint8_t *data, int size)
{
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 = BE_16 (&data[0]);
chunk_size = BE_16 (&data[2]) - 4;
data += 4;
chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
switch (chunk_id) {
case 0x2000:
case 0x2100:
case 0x2400:
case 0x2500:
cinepak_decode_codebook (strip->v4_codebook, chunk_id,
chunk_size, data);
break;
case 0x2200:
case 0x2300:
case 0x2600:
case 0x2700:
cinepak_decode_codebook (strip->v1_codebook, chunk_id,
chunk_size, data);
break;
case 0x3000:
case 0x3100:
case 0x3200:
return cinepak_decode_vectors (s, strip, chunk_id,
chunk_size, data);
}
data += chunk_size;
}
return -1;
}
static int cinepak_decode (CinepakContext *s)
{
uint8_t *eod = (s->data + s->size);
int i, result, strip_size, frame_flags, num_strips;
int y0 = 0;
if (s->size < 10)
return -1;
frame_flags = s->data[0];
num_strips = BE_16 (&s->data[8]);
s->data += 10;
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 = BE_16 (s->data);
s->strips[i].y1 = y0;
s->strips[i].x1 = 0;
s->strips[i].y2 = y0 + BE_16 (&s->data[8]);
s->strips[i].x2 = s->avctx->width;
strip_size = BE_16 (&s->data[2]) - 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 int cinepak_decode_init(AVCodecContext *avctx)
{
CinepakContext *s = (CinepakContext *)avctx->priv_data;
/*
int i;
unsigned char r, g, b;
unsigned char *raw_palette;
unsigned int *palette32;
*/
s->avctx = avctx;
s->width = (avctx->width + 3) & ~3;
s->height = (avctx->height + 3) & ~3;
// check for paletted data
s->palette_video = 0;
avctx->pix_fmt = PIX_FMT_YUV420P;
avctx->has_b_frames = 0;
dsputil_init(&s->dsp, avctx);
s->frame.data[0] = s->prev_frame.data[0] = NULL;
return 0;
}
static int cinepak_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
CinepakContext *s = (CinepakContext *)avctx->priv_data;
s->data = buf;
s->size = buf_size;
if (avctx->get_buffer(avctx, &s->frame)) {
av_log(avctx, AV_LOG_ERROR, " Cinepak: get_buffer() failed\n");
return -1;
}
cinepak_decode(s);
if (s->prev_frame.data[0])
avctx->release_buffer(avctx, &s->prev_frame);
/* shuffle frames */
s->prev_frame = s->frame;
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
/* report that the buffer was completely consumed */
return buf_size;
}
static int cinepak_decode_end(AVCodecContext *avctx)
{
CinepakContext *s = (CinepakContext *)avctx->priv_data;
if (s->prev_frame.data[0])
avctx->release_buffer(avctx, &s->prev_frame);
return 0;
}
AVCodec cinepak_decoder = {
"cinepak",
CODEC_TYPE_VIDEO,
CODEC_ID_CINEPAK,
sizeof(CinepakContext),
cinepak_decode_init,
NULL,
cinepak_decode_end,
cinepak_decode_frame,
CODEC_CAP_DR1,
};
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