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libavcodec/roqvideodec.c

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00001 /*
00002  * Copyright (C) 2003 the ffmpeg project
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00028 #include <stdio.h>
00029 #include <stdlib.h>
00030 #include <string.h>
00031 #include <unistd.h>
00032 
00033 #include "avcodec.h"
00034 #include "bytestream.h"
00035 #include "roqvideo.h"
00036 
00037 static void roqvideo_decode_frame(RoqContext *ri)
00038 {
00039     unsigned int chunk_id = 0, chunk_arg = 0;
00040     unsigned long chunk_size = 0;
00041     int i, j, k, nv1, nv2, vqflg = 0, vqflg_pos = -1;
00042     int vqid, bpos, xpos, ypos, xp, yp, x, y, mx, my;
00043     int frame_stats[2][4] = {{0},{0}};
00044     roq_qcell *qcell;
00045     const unsigned char *buf = ri->buf;
00046     const unsigned char *buf_end = ri->buf + ri->size;
00047 
00048     while (buf < buf_end) {
00049         chunk_id = bytestream_get_le16(&buf);
00050         chunk_size = bytestream_get_le32(&buf);
00051         chunk_arg = bytestream_get_le16(&buf);
00052 
00053         if(chunk_id == RoQ_QUAD_VQ)
00054             break;
00055         if(chunk_id == RoQ_QUAD_CODEBOOK) {
00056             if((nv1 = chunk_arg >> 8) == 0)
00057                 nv1 = 256;
00058             if((nv2 = chunk_arg & 0xff) == 0 && nv1 * 6 < chunk_size)
00059                 nv2 = 256;
00060             for(i = 0; i < nv1; i++) {
00061                 ri->cb2x2[i].y[0] = *buf++;
00062                 ri->cb2x2[i].y[1] = *buf++;
00063                 ri->cb2x2[i].y[2] = *buf++;
00064                 ri->cb2x2[i].y[3] = *buf++;
00065                 ri->cb2x2[i].u = *buf++;
00066                 ri->cb2x2[i].v = *buf++;
00067             }
00068             for(i = 0; i < nv2; i++)
00069                 for(j = 0; j < 4; j++)
00070                     ri->cb4x4[i].idx[j] = *buf++;
00071         }
00072     }
00073 
00074     bpos = xpos = ypos = 0;
00075     while(bpos < chunk_size) {
00076         for (yp = ypos; yp < ypos + 16; yp += 8)
00077             for (xp = xpos; xp < xpos + 16; xp += 8) {
00078                 if (vqflg_pos < 0) {
00079                     vqflg = buf[bpos++]; vqflg |= (buf[bpos++] << 8);
00080                     vqflg_pos = 7;
00081                 }
00082                 vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
00083                 frame_stats[0][vqid]++;
00084                 vqflg_pos--;
00085 
00086                 switch(vqid) {
00087                 case RoQ_ID_MOT:
00088                     break;
00089                 case RoQ_ID_FCC:
00090                     mx = 8 - (buf[bpos] >> 4) - ((signed char) (chunk_arg >> 8));
00091                     my = 8 - (buf[bpos++] & 0xf) - ((signed char) chunk_arg);
00092                     ff_apply_motion_8x8(ri, xp, yp, mx, my);
00093                     break;
00094                 case RoQ_ID_SLD:
00095                     qcell = ri->cb4x4 + buf[bpos++];
00096                     ff_apply_vector_4x4(ri, xp, yp, ri->cb2x2 + qcell->idx[0]);
00097                     ff_apply_vector_4x4(ri, xp+4, yp, ri->cb2x2 + qcell->idx[1]);
00098                     ff_apply_vector_4x4(ri, xp, yp+4, ri->cb2x2 + qcell->idx[2]);
00099                     ff_apply_vector_4x4(ri, xp+4, yp+4, ri->cb2x2 + qcell->idx[3]);
00100                     break;
00101                 case RoQ_ID_CCC:
00102                     for (k = 0; k < 4; k++) {
00103                         x = xp; y = yp;
00104                         if(k & 0x01) x += 4;
00105                         if(k & 0x02) y += 4;
00106 
00107                         if (vqflg_pos < 0) {
00108                             vqflg = buf[bpos++];
00109                             vqflg |= (buf[bpos++] << 8);
00110                             vqflg_pos = 7;
00111                         }
00112                         vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
00113                         frame_stats[1][vqid]++;
00114                         vqflg_pos--;
00115                         switch(vqid) {
00116                         case RoQ_ID_MOT:
00117                             break;
00118                         case RoQ_ID_FCC:
00119                             mx = 8 - (buf[bpos] >> 4) - ((signed char) (chunk_arg >> 8));
00120                             my = 8 - (buf[bpos++] & 0xf) - ((signed char) chunk_arg);
00121                             ff_apply_motion_4x4(ri, x, y, mx, my);
00122                             break;
00123                         case RoQ_ID_SLD:
00124                             qcell = ri->cb4x4 + buf[bpos++];
00125                             ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + qcell->idx[0]);
00126                             ff_apply_vector_2x2(ri, x+2, y, ri->cb2x2 + qcell->idx[1]);
00127                             ff_apply_vector_2x2(ri, x, y+2, ri->cb2x2 + qcell->idx[2]);
00128                             ff_apply_vector_2x2(ri, x+2, y+2, ri->cb2x2 + qcell->idx[3]);
00129                             break;
00130                         case RoQ_ID_CCC:
00131                             ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + buf[bpos]);
00132                             ff_apply_vector_2x2(ri, x+2, y, ri->cb2x2 + buf[bpos+1]);
00133                             ff_apply_vector_2x2(ri, x, y+2, ri->cb2x2 + buf[bpos+2]);
00134                             ff_apply_vector_2x2(ri, x+2, y+2, ri->cb2x2 + buf[bpos+3]);
00135                             bpos += 4;
00136                             break;
00137                         }
00138                     }
00139                     break;
00140                 default:
00141                     av_log(ri->avctx, AV_LOG_ERROR, "Unknown vq code: %d\n", vqid);
00142             }
00143         }
00144 
00145         xpos += 16;
00146         if (xpos >= ri->width) {
00147             xpos -= ri->width;
00148             ypos += 16;
00149         }
00150         if(ypos >= ri->height)
00151             break;
00152     }
00153 }
00154 
00155 
00156 static av_cold int roq_decode_init(AVCodecContext *avctx)
00157 {
00158     RoqContext *s = avctx->priv_data;
00159 
00160     s->avctx = avctx;
00161     s->width = avctx->width;
00162     s->height = avctx->height;
00163     s->last_frame    = &s->frames[0];
00164     s->current_frame = &s->frames[1];
00165     avctx->pix_fmt = PIX_FMT_YUV444P;
00166 
00167     return 0;
00168 }
00169 
00170 static int roq_decode_frame(AVCodecContext *avctx,
00171                             void *data, int *data_size,
00172                             const uint8_t *buf, int buf_size)
00173 {
00174     RoqContext *s = avctx->priv_data;
00175     int copy= !s->current_frame->data[0];
00176 
00177     if (avctx->reget_buffer(avctx, s->current_frame)) {
00178         av_log(avctx, AV_LOG_ERROR, "  RoQ: get_buffer() failed\n");
00179         return -1;
00180     }
00181 
00182     if(copy)
00183         av_picture_copy((AVPicture*)s->current_frame, (AVPicture*)s->last_frame,
00184                         avctx->pix_fmt, avctx->width, avctx->height);
00185 
00186     s->buf = buf;
00187     s->size = buf_size;
00188     roqvideo_decode_frame(s);
00189 
00190     *data_size = sizeof(AVFrame);
00191     *(AVFrame*)data = *s->current_frame;
00192 
00193     /* shuffle frames */
00194     FFSWAP(AVFrame *, s->current_frame, s->last_frame);
00195 
00196     return buf_size;
00197 }
00198 
00199 static av_cold int roq_decode_end(AVCodecContext *avctx)
00200 {
00201     RoqContext *s = avctx->priv_data;
00202 
00203     /* release the last frame */
00204     if (s->last_frame->data[0])
00205         avctx->release_buffer(avctx, s->last_frame);
00206     if (s->current_frame->data[0])
00207         avctx->release_buffer(avctx, s->current_frame);
00208 
00209     return 0;
00210 }
00211 
00212 AVCodec roq_decoder = {
00213     "roqvideo",
00214     CODEC_TYPE_VIDEO,
00215     CODEC_ID_ROQ,
00216     sizeof(RoqContext),
00217     roq_decode_init,
00218     NULL,
00219     roq_decode_end,
00220     roq_decode_frame,
00221     CODEC_CAP_DR1,
00222     .long_name = NULL_IF_CONFIG_SMALL("id RoQ video"),
00223 };

Generated on Sat Feb 16 2013 09:23:13 for ffmpeg by  doxygen 1.7.1