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/*
* Intel Indeo 2 codec
* Copyright (c) 2005 Konstantin Shishkov
*
* 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 indeo2.c
* Intel Indeo 2 decoder.
*/
#define ALT_BITSTREAM_READER_LE
#include "avcodec.h"
#include "bitstream.h"
#include "indeo2data.h"
typedef struct Ir2Context{
AVCodecContext *avctx;
AVFrame picture;
GetBitContext gb;
int decode_delta;
} Ir2Context;
#define CODE_VLC_BITS 14
static VLC ir2_vlc;
/* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */
static inline int ir2_get_code(GetBitContext *gb)
{
return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1) + 1;
}
static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
const uint8_t *table)
{
int i;
int j;
int out = 0;
int c;
int t;
if(width&1)
return -1;
/* first line contain absolute values, other lines contain deltas */
while (out < width){
c = ir2_get_code(&ctx->gb);
if(c >= 0x80) { /* we have a run */
c -= 0x7F;
if(out + c*2 > width)
return -1;
for (i = 0; i < c * 2; i++)
dst[out++] = 0x80;
} else { /* copy two values from table */
dst[out++] = table[c * 2];
dst[out++] = table[(c * 2) + 1];
}
}
dst += stride;
for (j = 1; j < height; j++){
out = 0;
while (out < width){
c = ir2_get_code(&ctx->gb);
if(c >= 0x80) { /* we have a skip */
c -= 0x7F;
if(out + c*2 > width)
return -1;
for (i = 0; i < c * 2; i++) {
dst[out] = dst[out - stride];
out++;
}
} else { /* add two deltas from table */
t = dst[out - stride] + (table[c * 2] - 128);
t= av_clip_uint8(t);
dst[out] = t;
out++;
t = dst[out - stride] + (table[(c * 2) + 1] - 128);
t= av_clip_uint8(t);
dst[out] = t;
out++;
}
}
dst += stride;
}
return 0;
}
static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int stride,
const uint8_t *table)
{
int j;
int out = 0;
int c;
int t;
if(width&1)
return -1;
for (j = 0; j < height; j++){
out = 0;
while (out < width){
c = ir2_get_code(&ctx->gb);
if(c >= 0x80) { /* we have a skip */
c -= 0x7F;
out += c * 2;
} else { /* add two deltas from table */
t = dst[out] + (((table[c * 2] - 128)*3) >> 2);
t= av_clip_uint8(t);
dst[out] = t;
out++;
t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);
t= av_clip_uint8(t);
dst[out] = t;
out++;
}
}
dst += stride;
}
return 0;
}
static int ir2_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
Ir2Context * const s = avctx->priv_data;
AVFrame *picture = data;
AVFrame * const p= (AVFrame*)&s->picture;
int start;
if(p->data[0])
avctx->release_buffer(avctx, p);
p->reference = 1;
p->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
if (avctx->reget_buffer(avctx, p)) {
av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
s->decode_delta = buf[18];
/* decide whether frame uses deltas or not */
#ifndef ALT_BITSTREAM_READER_LE
for (i = 0; i < buf_size; i++)
buf[i] = ff_reverse[buf[i]];
#endif
start = 48; /* hardcoded for now */
init_get_bits(&s->gb, buf + start, buf_size - start);
if (s->decode_delta) { /* intraframe */
ir2_decode_plane(s, avctx->width, avctx->height,
s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
/* swapped U and V */
ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,
s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
} else { /* interframe */
ir2_decode_plane_inter(s, avctx->width, avctx->height,
s->picture.data[0], s->picture.linesize[0], ir2_luma_table);
/* swapped U and V */
ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
s->picture.data[2], s->picture.linesize[2], ir2_luma_table);
ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,
s->picture.data[1], s->picture.linesize[1], ir2_luma_table);
}
*picture= *(AVFrame*)&s->picture;
*data_size = sizeof(AVPicture);
return buf_size;
}
static int ir2_decode_init(AVCodecContext *avctx){
Ir2Context * const ic = avctx->priv_data;
ic->avctx = avctx;
avctx->pix_fmt= PIX_FMT_YUV410P;
if (!ir2_vlc.table)
init_vlc(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,
&ir2_codes[0][1], 4, 2,
#ifdef ALT_BITSTREAM_READER_LE
&ir2_codes[0][0], 4, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
#else
&ir2_codes[0][0], 4, 2, INIT_VLC_USE_STATIC);
#endif
return 0;
}
AVCodec indeo2_decoder = {
"indeo2",
CODEC_TYPE_VIDEO,
CODEC_ID_INDEO2,
sizeof(Ir2Context),
ir2_decode_init,
NULL,
NULL,
ir2_decode_frame,
CODEC_CAP_DR1,
};
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