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/*
* ATI VCR1 codec
* Copyright (c) 2003 Michael Niedermayer
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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 "internal.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 & 7) {
av_log(avctx, AV_LOG_ERROR, "Width %d is not divisble by 8.\n", avctx->width);
return AVERROR_INVALIDDATA;
}
return 0;
}
static int vcr1_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
VCR1Context *const a = avctx->priv_data;
AVFrame *const p = data;
const uint8_t *bytestream = buf;
int i, x, y, ret;
if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
p->pict_type = AV_PICTURE_TYPE_I;
p->key_frame = 1;
if (buf_size < 32)
goto packet_small;
for (i = 0; i < 16; i++) {
a->delta[i] = *bytestream++;
bytestream++;
buf_size--;
}
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]];
if (buf_size < 4 + avctx->width)
goto packet_small;
for (i = 0; i < 4; i++)
a->offset[i] = *bytestream++;
buf_size -= 4;
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;
buf_size -= 4;
}
} else {
if (buf_size < avctx->width / 2)
goto packet_small;
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;
buf_size -= 4;
}
}
}
*got_frame = 1;
return buf_size;
packet_small:
av_log(avctx, AV_LOG_ERROR, "Input packet too small.\n");
return AVERROR_INVALIDDATA;
}
AVCodec ff_vcr1_decoder = {
.name = "vcr1",
.long_name = NULL_IF_CONFIG_SMALL("ATI VCR1"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_VCR1,
.priv_data_size = sizeof(VCR1Context),
.init = vcr1_decode_init,
.decode = vcr1_decode_frame,
.capabilities = CODEC_CAP_DR1,
};
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