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/*
* Electronic Arts CMV Video Decoder
* Copyright (c) 2007-2008 Peter Ross
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file libavcodec/eacmv.c
* Electronic Arts CMV Video Decoder
* by Peter Ross (suxen_drol at hotmail dot com)
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=Electronic_Arts_CMV
*/
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
typedef struct CmvContext {
AVCodecContext *avctx;
AVFrame frame; ///< current
AVFrame last_frame; ///< last
AVFrame last2_frame; ///< second-last
int width, height;
unsigned int palette[AVPALETTE_COUNT];
} CmvContext;
static av_cold int cmv_decode_init(AVCodecContext *avctx){
CmvContext *s = avctx->priv_data;
s->avctx = avctx;
avctx->pix_fmt = PIX_FMT_PAL8;
return 0;
}
static void cmv_decode_intra(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
unsigned char *dst = s->frame.data[0];
int i;
for (i=0; i < s->avctx->height && buf+s->avctx->width<=buf_end; i++) {
memcpy(dst, buf, s->avctx->width);
dst += s->frame.linesize[0];
buf += s->avctx->width;
}
}
static void cmv_motcomp(unsigned char *dst, int dst_stride,
const unsigned char *src, int src_stride,
int x, int y,
int xoffset, int yoffset,
int width, int height){
int i,j;
for(j=y;j<y+4;j++)
for(i=x;i<x+4;i++)
{
if (i+xoffset>=0 && i+xoffset<width &&
j+yoffset>=0 && j+yoffset<height) {
dst[j*dst_stride + i] = src[(j+yoffset)*src_stride + i+xoffset];
}else{
dst[j*dst_stride + i] = 0;
}
}
}
static void cmv_decode_inter(CmvContext * s, const uint8_t *buf, const uint8_t *buf_end){
const uint8_t *raw = buf + (s->avctx->width*s->avctx->height/16);
int x,y,i;
i = 0;
for(y=0; y<s->avctx->height/4; y++)
for(x=0; x<s->avctx->width/4 && buf+i<buf_end; x++) {
if (buf[i]==0xFF) {
unsigned char *dst = s->frame.data[0] + (y*4)*s->frame.linesize[0] + x*4;
if (raw+16<buf_end && *raw==0xFF) { /* intra */
raw++;
memcpy(dst, raw, 4);
memcpy(dst+s->frame.linesize[0], raw+4, 4);
memcpy(dst+2*s->frame.linesize[0], raw+8, 4);
memcpy(dst+3*s->frame.linesize[0], raw+12, 4);
raw+=16;
}else if(raw<buf_end) { /* inter using second-last frame as reference */
int xoffset = (*raw & 0xF) - 7;
int yoffset = ((*raw >> 4)) - 7;
cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
s->last2_frame.data[0], s->last2_frame.linesize[0],
x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
raw++;
}
}else{ /* inter using last frame as reference */
int xoffset = (buf[i] & 0xF) - 7;
int yoffset = ((buf[i] >> 4)) - 7;
cmv_motcomp(s->frame.data[0], s->frame.linesize[0],
s->last_frame.data[0], s->last_frame.linesize[0],
x*4, y*4, xoffset, yoffset, s->avctx->width, s->avctx->height);
}
i++;
}
}
static void cmv_process_header(CmvContext *s, const uint8_t *buf, const uint8_t *buf_end)
{
int pal_start, pal_count, i;
if(buf+16>=buf_end) {
av_log(s->avctx, AV_LOG_WARNING, "truncated header\n");
return;
}
s->width = AV_RL16(&buf[4]);
s->height = AV_RL16(&buf[6]);
if (s->avctx->width!=s->width || s->avctx->height!=s->height)
avcodec_set_dimensions(s->avctx, s->width, s->height);
s->avctx->time_base.num = 1;
s->avctx->time_base.den = AV_RL16(&buf[10]);
pal_start = AV_RL16(&buf[12]);
pal_count = AV_RL16(&buf[14]);
buf += 16;
for (i=pal_start; i<pal_start+pal_count && i<AVPALETTE_COUNT && buf+2<buf_end; i++) {
s->palette[i] = AV_RB24(buf);
buf += 3;
}
}
#define EA_PREAMBLE_SIZE 8
#define MVIh_TAG MKTAG('M', 'V', 'I', 'h')
static int cmv_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
CmvContext *s = avctx->priv_data;
const uint8_t *buf_end = buf + buf_size;
if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
return buf_size;
}
if (avcodec_check_dimensions(s->avctx, s->width, s->height))
return -1;
/* shuffle */
if (s->last2_frame.data[0])
avctx->release_buffer(avctx, &s->last2_frame);
FFSWAP(AVFrame, s->last_frame, s->last2_frame);
FFSWAP(AVFrame, s->frame, s->last_frame);
s->frame.reference = 1;
s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
if (avctx->get_buffer(avctx, &s->frame)<0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
buf += EA_PREAMBLE_SIZE;
if ((buf[0]&1)) { // subtype
cmv_decode_inter(s, buf+2, buf_end);
s->frame.key_frame = 0;
s->frame.pict_type = FF_P_TYPE;
}else{
s->frame.key_frame = 1;
s->frame.pict_type = FF_I_TYPE;
cmv_decode_intra(s, buf+2, buf_end);
}
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
return buf_size;
}
static av_cold int cmv_decode_end(AVCodecContext *avctx){
CmvContext *s = avctx->priv_data;
if (s->frame.data[0])
s->avctx->release_buffer(avctx, &s->frame);
if (s->last_frame.data[0])
s->avctx->release_buffer(avctx, &s->last_frame);
if (s->last2_frame.data[0])
s->avctx->release_buffer(avctx, &s->last2_frame);
return 0;
}
AVCodec eacmv_decoder = {
"eacmv",
CODEC_TYPE_VIDEO,
CODEC_ID_CMV,
sizeof(CmvContext),
cmv_decode_init,
NULL,
cmv_decode_end,
cmv_decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV Video"),
};
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