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ffmpeg/libavcodec/vb.c

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/*
* Beam Software VB decoder
* Copyright (c) 2007 Konstantin Shishkov
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* VB Video decoder
*/
#include <stdio.h>
#include <stdlib.h>
#include "avcodec.h"
#include "bytestream.h"
enum VBFlags{
VB_HAS_GMC = 0x01,
VB_HAS_AUDIO = 0x04,
VB_HAS_VIDEO = 0x08,
VB_HAS_PALETTE = 0x10,
VB_HAS_LENGTH = 0x20
};
typedef struct VBDecContext {
AVCodecContext *avctx;
AVFrame pic;
uint8_t *frame, *prev_frame;
uint32_t pal[AVPALETTE_COUNT];
const uint8_t *stream;
} VBDecContext;
static const uint16_t vb_patterns[64] = {
0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
};
static void vb_decode_palette(VBDecContext *c, int data_size)
{
int start, size, i;
start = bytestream_get_byte(&c->stream);
size = (bytestream_get_byte(&c->stream) - 1) & 0xFF;
if(start + size > 255){
av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
return;
}
if(size*3+2 > data_size){
av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
return;
}
for(i = start; i <= start + size; i++)
c->pal[i] = 0xFF << 24 | bytestream_get_be24(&c->stream);
}
static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
{
return buf >= start && buf < end;
}
static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
{
return buf >= start && (buf + 4) <= end;
}
static int vb_decode_framedata(VBDecContext *c, const uint8_t *buf, int data_size, int offset)
{
uint8_t *prev, *cur;
const uint8_t* data_end = buf + data_size;
int blk, blocks, t, blk2;
int blocktypes = 0;
int x, y, a, b;
int pattype, pattern;
const int width = c->avctx->width;
uint8_t *pstart = c->prev_frame;
uint8_t *pend = c->prev_frame + width*c->avctx->height;
prev = c->prev_frame + offset;
cur = c->frame;
blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
blk2 = 0;
for(blk = 0; blk < blocks; blk++){
if(!(blk & 3)) {
if(buf >= data_end){
av_log(c->avctx, AV_LOG_ERROR, "Data pointer out of bounds\n");
return -1;
}
blocktypes = bytestream_get_byte(&buf);
}
switch(blocktypes & 0xC0){
case 0x00: //skip
for(y = 0; y < 4; y++)
if(check_line(prev + y*width, pstart, pend))
memcpy(cur + y*width, prev + y*width, 4);
else
memset(cur + y*width, 0, 4);
break;
case 0x40:
t = bytestream_get_byte(&buf);
if(!t){ //raw block
if(buf + 16 > data_end){
av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
return -1;
}
for(y = 0; y < 4; y++)
memcpy(cur + y*width, buf + y*4, 4);
buf += 16;
}else{ // motion compensation
x = ((t & 0xF)^8) - 8;
y = ((t >> 4) ^8) - 8;
t = x + y*width;
for(y = 0; y < 4; y++)
if(check_line(prev + t + y*width, pstart, pend))
memcpy(cur + y*width, prev + t + y*width, 4);
else
memset(cur + y*width, 0, 4);
}
break;
case 0x80: // fill
t = bytestream_get_byte(&buf);
for(y = 0; y < 4; y++)
memset(cur + y*width, t, 4);
break;
case 0xC0: // pattern fill
if(buf + 2 > data_end){
av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
return -1;
}
t = bytestream_get_byte(&buf);
pattype = t >> 6;
pattern = vb_patterns[t & 0x3F];
switch(pattype){
case 0:
a = bytestream_get_byte(&buf);
b = bytestream_get_byte(&buf);
for(y = 0; y < 4; y++)
for(x = 0; x < 4; x++, pattern >>= 1)
cur[x + y*width] = (pattern & 1) ? b : a;
break;
case 1:
pattern = ~pattern;
case 2:
a = bytestream_get_byte(&buf);
for(y = 0; y < 4; y++)
for(x = 0; x < 4; x++, pattern >>= 1)
if(pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
cur[x + y*width] = prev[x + y*width];
else
cur[x + y*width] = a;
break;
case 3:
av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk);
return -1;
}
break;
}
blocktypes <<= 2;
cur += 4;
prev += 4;
blk2++;
if(blk2 == (width >> 2)){
blk2 = 0;
cur += width * 3;
prev += width * 3;
}
}
return 0;
}
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
VBDecContext * const c = avctx->priv_data;
uint8_t *outptr, *srcptr;
int i, j;
int flags;
uint32_t size;
int rest = buf_size;
int offset = 0;
if(c->pic.data[0])
avctx->release_buffer(avctx, &c->pic);
c->pic.reference = 3;
if(avctx->get_buffer(avctx, &c->pic) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
c->stream = buf;
flags = bytestream_get_le16(&c->stream);
rest -= 2;
if(flags & VB_HAS_GMC){
i = (int16_t)bytestream_get_le16(&c->stream);
j = (int16_t)bytestream_get_le16(&c->stream);
offset = i + j * avctx->width;
rest -= 4;
}
if(flags & VB_HAS_VIDEO){
size = bytestream_get_le32(&c->stream);
if(size > rest){
av_log(avctx, AV_LOG_ERROR, "Frame size is too big\n");
return -1;
}
vb_decode_framedata(c, c->stream, size, offset);
c->stream += size - 4;
rest -= size;
}
if(flags & VB_HAS_PALETTE){
size = bytestream_get_le32(&c->stream);
if(size > rest){
av_log(avctx, AV_LOG_ERROR, "Palette size is too big\n");
return -1;
}
vb_decode_palette(c, size);
rest -= size;
}
memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
c->pic.palette_has_changed = flags & VB_HAS_PALETTE;
outptr = c->pic.data[0];
srcptr = c->frame;
for(i = 0; i < avctx->height; i++){
memcpy(outptr, srcptr, avctx->width);
srcptr += avctx->width;
outptr += c->pic.linesize[0];
}
FFSWAP(uint8_t*, c->frame, c->prev_frame);
*data_size = sizeof(AVFrame);
*(AVFrame*)data = c->pic;
/* always report that the buffer was completely consumed */
return buf_size;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
VBDecContext * const c = avctx->priv_data;
c->avctx = avctx;
avctx->pix_fmt = PIX_FMT_PAL8;
avcodec_get_frame_defaults(&c->pic);
c->frame = av_mallocz(avctx->width * avctx->height);
c->prev_frame = av_mallocz(avctx->width * avctx->height);
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx)
{
VBDecContext *c = avctx->priv_data;
av_freep(&c->frame);
av_freep(&c->prev_frame);
if(c->pic.data[0])
avctx->release_buffer(avctx, &c->pic);
return 0;
}
AVCodec ff_vb_decoder = {
.name = "vb",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_VB,
.priv_data_size = sizeof(VBDecContext),
.init = decode_init,
.close = decode_end,
.decode = decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"),
};
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