ffmpeg/libavcodec/vcr1.c

134 lines
4.4 KiB
C

/*
* ATI VCR1 codec
* Copyright (c) 2003 Michael Niedermayer
*
* 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
* ATI VCR1 codec
*/
#include "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
#include "libavutil/avassert.h"
#include "libavutil/internal.h"
typedef struct VCR1Context {
int delta[16];
int offset[4];
} VCR1Context;
static av_cold int vcr1_decode_init(AVCodecContext *avctx)
{
avctx->pix_fmt = AV_PIX_FMT_YUV410P;
if (avctx->width % 8 || avctx->height%4) {
avpriv_request_sample(avctx, "odd dimensions (%d x %d) support", avctx->width, avctx->height);
return AVERROR_INVALIDDATA;
}
return 0;
}
static int vcr1_decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
VCR1Context *const a = avctx->priv_data;
const uint8_t *bytestream = avpkt->data;
const uint8_t *bytestream_end = bytestream + avpkt->size;
int i, x, y, ret;
if(avpkt->size < 32 + avctx->height + avctx->width*avctx->height*5/8){
av_log(avctx, AV_LOG_ERROR, "Insufficient input data. %d < %d\n", avpkt->size , 32 + avctx->height + avctx->width*avctx->height*5/8);
return AVERROR(EINVAL);
}
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
p->pict_type = AV_PICTURE_TYPE_I;
p->key_frame = 1;
for (i = 0; i < 16; i++) {
a->delta[i] = *bytestream++;
bytestream++;
}
for (y = 0; y < avctx->height; y++) {
int offset;
uint8_t *luma = &p->data[0][y * p->linesize[0]];
if ((y & 3) == 0) {
uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]];
uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]];
av_assert0 (bytestream_end - bytestream >= 4 + avctx->width);
for (i = 0; i < 4; i++)
a->offset[i] = *bytestream++;
offset = a->offset[0] - a->delta[bytestream[2] & 0xF];
for (x = 0; x < avctx->width; x += 4) {
luma[0] = offset += a->delta[bytestream[2] & 0xF];
luma[1] = offset += a->delta[bytestream[2] >> 4];
luma[2] = offset += a->delta[bytestream[0] & 0xF];
luma[3] = offset += a->delta[bytestream[0] >> 4];
luma += 4;
*cb++ = bytestream[3];
*cr++ = bytestream[1];
bytestream += 4;
}
} else {
av_assert0 (bytestream_end - bytestream >= avctx->width / 2);
offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF];
for (x = 0; x < avctx->width; x += 8) {
luma[0] = offset += a->delta[bytestream[2] & 0xF];
luma[1] = offset += a->delta[bytestream[2] >> 4];
luma[2] = offset += a->delta[bytestream[3] & 0xF];
luma[3] = offset += a->delta[bytestream[3] >> 4];
luma[4] = offset += a->delta[bytestream[0] & 0xF];
luma[5] = offset += a->delta[bytestream[0] >> 4];
luma[6] = offset += a->delta[bytestream[1] & 0xF];
luma[7] = offset += a->delta[bytestream[1] >> 4];
luma += 8;
bytestream += 4;
}
}
}
*got_frame = 1;
return bytestream - avpkt->data;
}
const FFCodec ff_vcr1_decoder = {
.p.name = "vcr1",
CODEC_LONG_NAME("ATI VCR1"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_VCR1,
.priv_data_size = sizeof(VCR1Context),
.init = vcr1_decode_init,
FF_CODEC_DECODE_CB(vcr1_decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
};