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/*
* Duck TrueMotion 2.0 Real Time Decoder
*
* 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
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "avcodec.h"
#define BITSTREAM_READER_LE
#include "get_bits.h"
#include "internal.h"
#include "libavutil/imgutils.h"
#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mem.h"
typedef struct TrueMotion2RTContext {
GetBitContext gb;
const uint8_t *buf;
int size;
int delta_size;
int hscale;
} TrueMotion2RTContext;
static av_cold int decode_init(AVCodecContext *avctx)
{
avctx->pix_fmt = AV_PIX_FMT_YUV410P;
return 0;
}
/* Returns the number of bytes consumed from the bytestream. Returns -1 if
* there was an error while decoding the header */
static int truemotion2rt_decode_header(AVCodecContext *avctx)
{
TrueMotion2RTContext *s = avctx->priv_data;
uint8_t header_buffer[128] = { 0 }; /* logical maximum size of the header */
int i, header_size;
header_size = ((s->buf[0] >> 5) | (s->buf[0] << 3)) & 0x7f;
if (header_size < 10) {
av_log(avctx, AV_LOG_ERROR, "invalid header size (%d)\n", header_size);
return AVERROR_INVALIDDATA;
}
if (header_size + 1 > s->size) {
av_log(avctx, AV_LOG_ERROR, "Input packet too small.\n");
return AVERROR_INVALIDDATA;
}
/* unscramble the header bytes with a XOR operation */
for (i = 1; i < header_size; i++)
header_buffer[i - 1] = s->buf[i] ^ s->buf[i + 1];
s->delta_size = header_buffer[1];
s->hscale = 1 + !!header_buffer[3];
if (s->delta_size < 2 || s->delta_size > 4)
return AVERROR_INVALIDDATA;
avctx->height = AV_RL16(header_buffer + 5);
avctx->width = AV_RL16(header_buffer + 7);
return header_size;
}
static const int16_t delta_tab4[] = {
1, -1, 2, -3, 8, -8, 18, -18, 36, -36, 54, -54, 96, -96, 144, -144
};
static const int16_t delta_tab3[] = {
2, -3, 8, -8, 18, -18, 36, -36
};
static const int16_t delta_tab2[] = {
5, -7, 36, -36
};
static const int16_t *const delta_tabs[] = {
delta_tab2, delta_tab3, delta_tab4,
};
static int decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
TrueMotion2RTContext *s = avctx->priv_data;
const uint8_t *buf = avpkt->data;
int ret, buf_size = avpkt->size;
AVFrame * const p = data;
GetBitContext *gb = &s->gb;
uint8_t *dst;
int x, y, delta_mode;
s->buf = buf;
s->size = buf_size;
if ((ret = truemotion2rt_decode_header(avctx)) < 0)
return ret;
if ((ret = init_get_bits8(gb, buf + ret, buf_size - ret)) < 0)
return ret;
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
skip_bits(gb, 32);
delta_mode = s->delta_size - 2;
dst = p->data[0];
for (y = 0; y < avctx->height; y++) {
int diff = 0;
for (x = 0; x < avctx->width; x += s->hscale) {
diff += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
dst[x] = av_clip_uint8((y ? dst[x - p->linesize[0]] : 0) + diff);
}
dst += p->linesize[0];
}
if (s->hscale > 1) {
dst = p->data[0];
for (y = 0; y < avctx->height; y++) {
for (x = 1; x < avctx->width; x += s->hscale) {
dst[x] = dst[x - 1];
}
dst += p->linesize[0];
}
}
dst = p->data[0];
for (y = 0; y < avctx->height; y++) {
for (x = 0; x < avctx->width; x++)
dst[x] = av_clip_uint8(dst[x] + (dst[x] - 128) / 3);
dst += p->linesize[0];
}
dst = p->data[1];
for (y = 0; y < avctx->height >> 2; y++) {
int diff = 0;
for (x = 0; x < avctx->width >> 2; x += s->hscale) {
diff += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
dst[x] = av_clip_uint8((y ? dst[x - p->linesize[1]] : 128) + diff);
}
dst += p->linesize[1];
}
if (s->hscale > 1) {
dst = p->data[1];
for (y = 0; y < avctx->height >> 2; y++) {
for (x = 1; x < avctx->width >> 2; x += s->hscale) {
dst[x] = dst[x - 1];
}
dst += p->linesize[1];
}
}
dst = p->data[1];
for (y = 0; y < avctx->height >> 2; y++) {
for (x = 0; x < avctx->width >> 2; x++)
dst[x] += (dst[x] - 128) / 8;
dst += p->linesize[1];
}
dst = p->data[2];
for (y = 0; y < avctx->height >> 2; y++) {
int diff = 0;
for (x = 0; x < avctx->width >> 2; x += s->hscale) {
diff += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
dst[x] = av_clip_uint8((y ? dst[x - p->linesize[2]] : 128) + diff);
}
dst += p->linesize[2];
}
if (s->hscale > 1) {
dst = p->data[2];
for (y = 0; y < avctx->height >> 2; y++) {
for (x = 1; x < avctx->width >> 2; x += s->hscale) {
dst[x] = dst[x - 1];
}
dst += p->linesize[2];
}
}
dst = p->data[2];
for (y = 0; y < avctx->height >> 2; y++) {
for (x = 0; x < avctx->width >> 2; x++)
dst[x] += (dst[x] - 128) / 8;
dst += p->linesize[2];
}
p->pict_type = AV_PICTURE_TYPE_I;
p->key_frame = 1;
*got_frame = 1;
return buf_size;
}
AVCodec ff_truemotion2rt_decoder = {
.name = "truemotion2rt",
.long_name = NULL_IF_CONFIG_SMALL("Duck TrueMotion 2.0 Real Time"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_TRUEMOTION2RT,
.priv_data_size = sizeof(TrueMotion2RTContext),
.init = decode_init,
.decode = decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};
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