320 lines
9.3 KiB
C
320 lines
9.3 KiB
C
/*
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* LOCO codec
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* Copyright (c) 2005 Konstantin Shishkov
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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/**
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* @file loco.c
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* LOCO codec.
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*/
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#include "avcodec.h"
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#include "common.h"
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#include "bitstream.h"
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#include "golomb.h"
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enum LOCO_MODE {LOCO_UNKN=0, LOCO_CYUY2=-1, LOCO_CRGB=-2, LOCO_CYV12=-3,
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LOCO_YUY2=1, LOCO_UYVY=2, LOCO_RGB=3, LOCO_RGBA=4, LOCO_YV12=5};
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typedef struct LOCOContext{
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AVCodecContext *avctx;
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AVFrame pic;
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int lossy;
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int mode;
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} LOCOContext;
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typedef struct RICEContext{
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GetBitContext gb;
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int save, run, run2; /* internal rice decoder state */
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int sum, count; /* sum and count for getting rice parameter */
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}RICEContext;
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/* could use get_sr_golomb() but is behaves differently on numbers like Rice(2, -64) */
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static inline int get_rice(GetBitContext *gb, int K)
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{
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int i;
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int V = 0;
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for(i = 0; !get_bits1(gb); i++);
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V = i;
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for(i = 0; i < K; i++) V = (V << 1) | get_bits1(gb);
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if(V & 1) return (V + 1) >> 1;
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return -(V >> 1);
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}
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static inline int get_u_rice(GetBitContext *gb, int K)
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{
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int i;
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int V = 0;
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for(i = 0; !get_bits1(gb); i++);
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V = i;
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for(i = 0; i < K; i++) V = (V << 1) | get_bits1(gb);
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return V;
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}
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static int loco_get_rice_param(RICEContext *r)
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{
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int cnt = 0;
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int val = r->count;
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while(r->sum > val && cnt < 9) {
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val <<= 1;
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cnt++;
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}
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return cnt;
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}
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static inline void loco_update_rice_param(RICEContext *r, int val)
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{
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if (val < 0)
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val = -val;
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r->sum += val;
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r->count++;
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if(r->count == 16) {
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r->sum >>= 1;
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r->count >>= 1;
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}
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}
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static inline int loco_get_rice(RICEContext *r)
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{
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int v;
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if (r->run > 0) { /* we have zero run */
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r->run--;
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return 0;
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}
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v = -get_rice(&r->gb, loco_get_rice_param(r));
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if (!v) {
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if (r->save >= 0) {
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r->run = get_u_rice(&r->gb, 2);
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if(r->run > 1)
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r->save += r->run + 1;
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else
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r->save -= 3;
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}
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else
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r->run2++;
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} else if (r->run2 > 0) {
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if (r->run2 > 2)
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r->save += r->run2;
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else
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r->save -= 3;
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r->run2 = 0;
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}
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return v;
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}
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/* LOCO main predictor - LOCO-I/JPEG-LS predictor */
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static inline int loco_predict(uint8_t* data, int stride, int step)
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{
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int max_ab, min_ab;
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int a, b, c;
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a = data[-stride];
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b = data[-step];
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c = data[-stride - step];
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max_ab = (a > b) ? a : b;
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min_ab = (a < b) ? a : b;
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if (c >= max_ab) return min_ab;
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if (c <= min_ab) return max_ab;
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return (a + b - c);
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}
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static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
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int stride, uint8_t *buf, int buf_size, int step)
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{
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RICEContext rc;
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int val;
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int i, j;
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init_get_bits(&rc.gb, buf, buf_size*8);
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rc.save = 0;
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rc.run = 0;
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rc.run2 = 0;
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rc.sum = 8;
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rc.count = 1;
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/* restore top left pixel */
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val = loco_get_rice(&rc);
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loco_update_rice_param(&rc, val);
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if (val < 0) val -= l->lossy;
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if (val > 0) val += l->lossy;
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data[0] = 128 + val;
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/* restore top line */
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for (i = 1; i < width; i++) {
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val = loco_get_rice(&rc);
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loco_update_rice_param(&rc, val);
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if (val < 0) val -= l->lossy;
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if (val > 0) val += l->lossy;
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data[i * step] = data[i * step - step] + val;
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}
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data += stride;
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for (j = 1; j < height; j++) {
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/* restore left column */
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val = loco_get_rice(&rc);
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loco_update_rice_param(&rc, val);
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if (val < 0) val -= l->lossy;
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if (val > 0) val += l->lossy;
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data[0] = data[-stride] + val;
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/* restore all other pixels */
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for (i = 1; i < width; i++) {
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val = loco_get_rice(&rc);
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loco_update_rice_param(&rc, val);
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if (val < 0) val -= l->lossy;
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if (val > 0) val += l->lossy;
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data[i * step] = loco_predict(&data[i * step], stride, step) + val;
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}
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data += stride;
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}
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return ((get_bits_count(&rc.gb) + 7) >> 3);
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}
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static int decode_frame(AVCodecContext *avctx,
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void *data, int *data_size,
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uint8_t *buf, int buf_size)
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{
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LOCOContext * const l = avctx->priv_data;
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AVFrame * const p= (AVFrame*)&l->pic;
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int decoded;
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if(p->data[0])
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avctx->release_buffer(avctx, p);
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p->reference = 0;
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if(avctx->get_buffer(avctx, p) < 0){
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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return -1;
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}
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p->key_frame = 1;
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switch(l->mode) {
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case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
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decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 1);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
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p->linesize[1], buf, buf_size, 1);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
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p->linesize[2], buf, buf_size, 1);
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break;
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case LOCO_CYV12: case LOCO_YV12:
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decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 1);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
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p->linesize[1], buf, buf_size, 1);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
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p->linesize[2], buf, buf_size, 1);
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break;
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case LOCO_CRGB: case LOCO_RGB:
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decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 3);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 3);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 3);
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break;
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case LOCO_RGBA:
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decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 4);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 4);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 4);
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buf += decoded; buf_size -= decoded;
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decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
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p->linesize[0], buf, buf_size, 4);
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break;
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}
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*data_size = sizeof(AVFrame);
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*(AVFrame*)data = l->pic;
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return buf_size;
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}
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static int decode_init(AVCodecContext *avctx){
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LOCOContext * const l = avctx->priv_data;
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int version;
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l->avctx = avctx;
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if (avctx->extradata_size < 12) {
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av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
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avctx->extradata_size);
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return -1;
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}
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version = LE_32(avctx->extradata);
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switch(version) {
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case 1:
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l->lossy = 0;
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break;
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case 2:
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l->lossy = LE_32(avctx->extradata + 8);
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break;
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default:
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l->lossy = LE_32(avctx->extradata + 8);
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av_log(avctx, AV_LOG_INFO, "This is LOCO codec version %i, please upload file for study\n", version);
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}
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l->mode = LE_32(avctx->extradata + 4);
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switch(l->mode) {
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case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
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avctx->pix_fmt = PIX_FMT_YUV422P;
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break;
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case LOCO_CRGB: case LOCO_RGB:
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avctx->pix_fmt = PIX_FMT_BGR24;
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break;
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case LOCO_CYV12: case LOCO_YV12:
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avctx->pix_fmt = PIX_FMT_YUV420P;
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break;
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case LOCO_RGBA:
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avctx->pix_fmt = PIX_FMT_RGBA32;
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break;
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default:
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av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
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return -1;
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}
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return 0;
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}
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AVCodec loco_decoder = {
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"loco",
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CODEC_TYPE_VIDEO,
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CODEC_ID_LOCO,
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sizeof(LOCOContext),
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decode_init,
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NULL,
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NULL,
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decode_frame,
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CODEC_CAP_DR1,
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};
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