/*
* 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
* Electronic Arts CMV Video Decoder
* by Peter Ross (pross@xvid.org)
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=Electronic_Arts_CMV
*/
#include "libavutil/common.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "internal.h"
typedef struct CmvContext {
AVCodecContext *avctx;
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 = AV_PIX_FMT_PAL8;
s->last_frame = av_frame_alloc();
s->last2_frame = av_frame_alloc();
if (!s->last_frame || !s->last2_frame) {
av_frame_free(&s->last_frame);
av_frame_free(&s->last2_frame);
return AVERROR(ENOMEM);
}
return 0;
}
static void cmv_decode_intra(CmvContext * s, AVFrame *frame,
const uint8_t *buf, const uint8_t *buf_end)
{
unsigned char *dst = frame->data[0];
int i;
for (i=0; i < s->avctx->height && buf_end - buf >= s->avctx->width; i++) {
memcpy(dst
, buf
, s
->avctx
->width
); dst += 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, AVFrame *frame, 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_end - buf > i; x++) {
if (buf[i]==0xFF) {
unsigned char *dst = frame->data[0] + (y*4)*frame->linesize[0] + x*4;
if (raw+16<buf_end && *raw==0xFF) { /* intra */
raw++;
memcpy(dst
+ frame
->linesize
[0], raw
+4, 4); memcpy(dst
+ 2 * frame
->linesize
[0], raw
+8, 4); memcpy(dst
+ 3 * 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;
if (s->last2_frame->data[0])
cmv_motcomp(frame->data[0], 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;
if (s->last_frame->data[0])
cmv_motcomp(frame->data[0], 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_end - buf < 16) {
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);
av_frame_unref(s->last_frame);
av_frame_unref(s->last2_frame);
}
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_end - buf >= 3; i++) {
s->palette[i] = 0xFFU << 24 | 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 *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
CmvContext *s = avctx->priv_data;
const uint8_t *buf_end = buf + buf_size;
AVFrame *frame = data;
int ret;
if (buf_end - buf < EA_PREAMBLE_SIZE)
return AVERROR_INVALIDDATA;
if (AV_RL32(buf)==MVIh_TAG||AV_RB32(buf)==MVIh_TAG) {
unsigned size = AV_RL32(buf + 4);
cmv_process_header(s, buf+EA_PREAMBLE_SIZE, buf_end);
if (size > buf_end - buf - EA_PREAMBLE_SIZE)
return -1;
buf += size;
}
if (av_image_check_size(s->width, s->height, 0, s->avctx))
return -1;
if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
return ret;
memcpy(frame
->data
[1], s
->palette
, AVPALETTE_SIZE
);
buf += EA_PREAMBLE_SIZE;
if ((buf[0]&1)) { // subtype
cmv_decode_inter(s, frame, buf+2, buf_end);
frame->key_frame = 0;
frame->pict_type = AV_PICTURE_TYPE_P;
}else{
frame->key_frame = 1;
frame->pict_type = AV_PICTURE_TYPE_I;
cmv_decode_intra(s, frame, buf+2, buf_end);
}
av_frame_unref(s->last2_frame);
av_frame_move_ref(s->last2_frame, s->last_frame);
if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
return ret;
*got_frame = 1;
return buf_size;
}
static av_cold int cmv_decode_end(AVCodecContext *avctx){
CmvContext *s = avctx->priv_data;
av_frame_free(&s->last_frame);
av_frame_free(&s->last2_frame);
return 0;
}
AVCodec ff_eacmv_decoder = {
.name = "eacmv",
.long_name = NULL_IF_CONFIG_SMALL("Electronic Arts CMV video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_CMV,
.priv_data_size = sizeof(CmvContext),
.init = cmv_decode_init,
.close = cmv_decode_end,
.decode = cmv_decode_frame,
.capabilities = CODEC_CAP_DR1,
};