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ffmpeg/libavcodec/loco.c

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/*
* LOCO 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
* LOCO codec.
*/
#include "avcodec.h"
#include "get_bits.h"
#include "golomb.h"
#include "mathops.h"
enum LOCO_MODE {LOCO_UNKN=0, LOCO_CYUY2=-1, LOCO_CRGB=-2, LOCO_CRGBA=-3, LOCO_CYV12=-4,
LOCO_YUY2=1, LOCO_UYVY=2, LOCO_RGB=3, LOCO_RGBA=4, LOCO_YV12=5};
typedef struct LOCOContext{
AVCodecContext *avctx;
AVFrame pic;
int lossy;
int mode;
} LOCOContext;
typedef struct RICEContext{
GetBitContext gb;
int save, run, run2; /* internal rice decoder state */
int sum, count; /* sum and count for getting rice parameter */
int lossy;
}RICEContext;
static int loco_get_rice_param(RICEContext *r)
{
int cnt = 0;
int val = r->count;
while(r->sum > val && cnt < 9) {
val <<= 1;
cnt++;
}
return cnt;
}
static inline void loco_update_rice_param(RICEContext *r, int val)
{
r->sum += val;
r->count++;
if(r->count == 16) {
r->sum >>= 1;
r->count >>= 1;
}
}
static inline int loco_get_rice(RICEContext *r)
{
int v;
if (r->run > 0) { /* we have zero run */
r->run--;
loco_update_rice_param(r, 0);
return 0;
}
v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
loco_update_rice_param(r, (v+1)>>1);
if (!v) {
if (r->save >= 0) {
r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
if(r->run > 1)
r->save += r->run + 1;
else
r->save -= 3;
}
else
r->run2++;
} else {
v = ((v>>1) + r->lossy) ^ -(v&1);
if (r->run2 > 0) {
if (r->run2 > 2)
r->save += r->run2;
else
r->save -= 3;
r->run2 = 0;
}
}
return v;
}
/* LOCO main predictor - LOCO-I/JPEG-LS predictor */
static inline int loco_predict(uint8_t* data, int stride, int step)
{
int a, b, c;
a = data[-stride];
b = data[-step];
c = data[-stride - step];
return mid_pred(a, a + b - c, b);
}
static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
int stride, const uint8_t *buf, int buf_size, int step)
{
RICEContext rc;
int val;
int i, j;
init_get_bits(&rc.gb, buf, buf_size*8);
rc.save = 0;
rc.run = 0;
rc.run2 = 0;
rc.lossy = l->lossy;
rc.sum = 8;
rc.count = 1;
/* restore top left pixel */
val = loco_get_rice(&rc);
data[0] = 128 + val;
/* restore top line */
for (i = 1; i < width; i++) {
val = loco_get_rice(&rc);
data[i * step] = data[i * step - step] + val;
}
data += stride;
for (j = 1; j < height; j++) {
/* restore left column */
val = loco_get_rice(&rc);
data[0] = data[-stride] + val;
/* restore all other pixels */
for (i = 1; i < width; i++) {
val = loco_get_rice(&rc);
data[i * step] = loco_predict(&data[i * step], stride, step) + val;
}
data += stride;
}
return (get_bits_count(&rc.gb) + 7) >> 3;
}
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
LOCOContext * const l = avctx->priv_data;
AVFrame * const p= (AVFrame*)&l->pic;
int decoded;
if(p->data[0])
avctx->release_buffer(avctx, p);
p->reference = 0;
if(avctx->get_buffer(avctx, p) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
p->key_frame = 1;
switch(l->mode) {
case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
p->linesize[0], buf, buf_size, 1);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
p->linesize[1], buf, buf_size, 1);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
p->linesize[2], buf, buf_size, 1);
break;
case LOCO_CYV12: case LOCO_YV12:
decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
p->linesize[0], buf, buf_size, 1);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
p->linesize[2], buf, buf_size, 1);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
p->linesize[1], buf, buf_size, 1);
break;
case LOCO_CRGB: case LOCO_RGB:
decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
-p->linesize[0], buf, buf_size, 3);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
-p->linesize[0], buf, buf_size, 3);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
-p->linesize[0], buf, buf_size, 3);
break;
case LOCO_RGBA:
decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
p->linesize[0], buf, buf_size, 4);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
p->linesize[0], buf, buf_size, 4);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
p->linesize[0], buf, buf_size, 4);
buf += decoded; buf_size -= decoded;
decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
p->linesize[0], buf, buf_size, 4);
break;
}
*data_size = sizeof(AVFrame);
*(AVFrame*)data = l->pic;
return buf_size;
}
static av_cold int decode_init(AVCodecContext *avctx){
LOCOContext * const l = avctx->priv_data;
int version;
l->avctx = avctx;
if (avctx->extradata_size < 12) {
av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
avctx->extradata_size);
return -1;
}
version = AV_RL32(avctx->extradata);
switch(version) {
case 1:
l->lossy = 0;
break;
case 2:
l->lossy = AV_RL32(avctx->extradata + 8);
break;
default:
l->lossy = AV_RL32(avctx->extradata + 8);
av_log_ask_for_sample(avctx, "This is LOCO codec version %i.\n", version);
}
l->mode = AV_RL32(avctx->extradata + 4);
switch(l->mode) {
case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
avctx->pix_fmt = PIX_FMT_YUV422P;
break;
case LOCO_CRGB: case LOCO_RGB:
avctx->pix_fmt = PIX_FMT_BGR24;
break;
case LOCO_CYV12: case LOCO_YV12:
avctx->pix_fmt = PIX_FMT_YUV420P;
break;
case LOCO_CRGBA: case LOCO_RGBA:
avctx->pix_fmt = PIX_FMT_RGB32;
break;
default:
av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
return -1;
}
if(avctx->debug & FF_DEBUG_PICT_INFO)
av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
avcodec_get_frame_defaults(&l->pic);
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx){
LOCOContext * const l = avctx->priv_data;
AVFrame *pic = &l->pic;
if (pic->data[0])
avctx->release_buffer(avctx, pic);
return 0;
}
AVCodec ff_loco_decoder = {
.name = "loco",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_LOCO,
.priv_data_size = sizeof(LOCOContext),
.init = decode_init,
.close = decode_end,
.decode = decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("LOCO"),
};
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