FFmpeg: libavcodec/roqvideodec.c Source File

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 "libavutil/avassert.h"
00029 #include "avcodec.h"
00030 #include "bytestream.h"
00031 #include "roqvideo.h"
00032 
00033 static void roqvideo_decode_frame(RoqContext *ri)
00034 {
00035     unsigned int chunk_id = 0, chunk_arg = 0;
00036     unsigned long chunk_size = 0;
00037     int i, j, k, nv1, nv2, vqflg = 0, vqflg_pos = -1;
00038     int vqid, xpos, ypos, xp, yp, x, y, mx, my;
00039     int frame_stats[2][4] = {{0},{0}};
00040     roq_qcell *qcell;
00041     int64_t chunk_start;
00042 
00043     while (bytestream2_get_bytes_left(&ri->gb) >= 8) {
00044         chunk_id   = bytestream2_get_le16(&ri->gb);
00045         chunk_size = bytestream2_get_le32(&ri->gb);
00046         chunk_arg  = bytestream2_get_le16(&ri->gb);
00047 
00048         if(chunk_id == RoQ_QUAD_VQ)
00049             break;
00050         if(chunk_id == RoQ_QUAD_CODEBOOK) {
00051             if((nv1 = chunk_arg >> 8) == 0)
00052                 nv1 = 256;
00053             if((nv2 = chunk_arg & 0xff) == 0 && nv1 * 6 < chunk_size)
00054                 nv2 = 256;
00055             for(i = 0; i < nv1; i++) {
00056                 ri->cb2x2[i].y[0] = bytestream2_get_byte(&ri->gb);
00057                 ri->cb2x2[i].y[1] = bytestream2_get_byte(&ri->gb);
00058                 ri->cb2x2[i].y[2] = bytestream2_get_byte(&ri->gb);
00059                 ri->cb2x2[i].y[3] = bytestream2_get_byte(&ri->gb);
00060                 ri->cb2x2[i].u    = bytestream2_get_byte(&ri->gb);
00061                 ri->cb2x2[i].v    = bytestream2_get_byte(&ri->gb);
00062             }
00063             for(i = 0; i < nv2; i++)
00064                 for(j = 0; j < 4; j++)
00065                     ri->cb4x4[i].idx[j] = bytestream2_get_byte(&ri->gb);
00066         }
00067     }
00068 
00069     chunk_start = bytestream2_tell(&ri->gb);
00070     xpos = ypos = 0;
00071 
00072     if (chunk_size > bytestream2_get_bytes_left(&ri->gb)) {
00073         av_log(ri->avctx, AV_LOG_ERROR, "Chunk does not fit in input buffer\n");
00074         chunk_size = bytestream2_get_bytes_left(&ri->gb);
00075     }
00076 
00077     while (bytestream2_tell(&ri->gb) < chunk_start + chunk_size) {
00078         for (yp = ypos; yp < ypos + 16; yp += 8)
00079             for (xp = xpos; xp < xpos + 16; xp += 8) {
00080                 if (bytestream2_tell(&ri->gb) >= chunk_start + chunk_size) {
00081                     av_log(ri->avctx, AV_LOG_ERROR, "Input buffer too small\n");
00082                     return;
00083                 }
00084                 if (vqflg_pos < 0) {
00085                     vqflg = bytestream2_get_le16(&ri->gb);
00086                     vqflg_pos = 7;
00087                 }
00088                 vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
00089                 frame_stats[0][vqid]++;
00090                 vqflg_pos--;
00091 
00092                 switch(vqid) {
00093                 case RoQ_ID_MOT:
00094                     break;
00095                 case RoQ_ID_FCC: {
00096                     int byte = bytestream2_get_byte(&ri->gb);
00097                     mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));
00098                     my = 8 - (byte & 0xf) - ((signed char) chunk_arg);
00099                     ff_apply_motion_8x8(ri, xp, yp, mx, my);
00100                     break;
00101                 }
00102                 case RoQ_ID_SLD:
00103                     qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);
00104                     ff_apply_vector_4x4(ri, xp,     yp,     ri->cb2x2 + qcell->idx[0]);
00105                     ff_apply_vector_4x4(ri, xp + 4, yp,     ri->cb2x2 + qcell->idx[1]);
00106                     ff_apply_vector_4x4(ri, xp,     yp + 4, ri->cb2x2 + qcell->idx[2]);
00107                     ff_apply_vector_4x4(ri, xp + 4, yp + 4, ri->cb2x2 + qcell->idx[3]);
00108                     break;
00109                 case RoQ_ID_CCC:
00110                     for (k = 0; k < 4; k++) {
00111                         x = xp; y = yp;
00112                         if(k & 0x01) x += 4;
00113                         if(k & 0x02) y += 4;
00114 
00115                         if (bytestream2_tell(&ri->gb) >= chunk_start + chunk_size) {
00116                             av_log(ri->avctx, AV_LOG_ERROR, "Input buffer too small\n");
00117                             return;
00118                         }
00119                         if (vqflg_pos < 0) {
00120                             vqflg = bytestream2_get_le16(&ri->gb);
00121                             vqflg_pos = 7;
00122                         }
00123                         vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
00124                         frame_stats[1][vqid]++;
00125                         vqflg_pos--;
00126                         switch(vqid) {
00127                         case RoQ_ID_MOT:
00128                             break;
00129                         case RoQ_ID_FCC: {
00130                             int byte = bytestream2_get_byte(&ri->gb);
00131                             mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));
00132                             my = 8 - (byte & 0xf) - ((signed char) chunk_arg);
00133                             ff_apply_motion_4x4(ri, x, y, mx, my);
00134                             break;
00135                         }
00136                         case RoQ_ID_SLD:
00137                             qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);
00138                             ff_apply_vector_2x2(ri, x,     y,     ri->cb2x2 + qcell->idx[0]);
00139                             ff_apply_vector_2x2(ri, x + 2, y,     ri->cb2x2 + qcell->idx[1]);
00140                             ff_apply_vector_2x2(ri, x,     y + 2, ri->cb2x2 + qcell->idx[2]);
00141                             ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + qcell->idx[3]);
00142                             break;
00143                         case RoQ_ID_CCC:
00144                             ff_apply_vector_2x2(ri, x,     y,     ri->cb2x2 + bytestream2_get_byte(&ri->gb));
00145                             ff_apply_vector_2x2(ri, x + 2, y,     ri->cb2x2 + bytestream2_get_byte(&ri->gb));
00146                             ff_apply_vector_2x2(ri, x,     y + 2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
00147                             ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));
00148                             break;
00149                         }
00150                     }
00151                     break;
00152                 default:
00153                     av_assert2(0);
00154             }
00155         }
00156 
00157         xpos += 16;
00158         if (xpos >= ri->width) {
00159             xpos -= ri->width;
00160             ypos += 16;
00161         }
00162         if(ypos >= ri->height)
00163             break;
00164     }
00165 }
00166 
00167 
00168 static av_cold int roq_decode_init(AVCodecContext *avctx)
00169 {
00170     RoqContext *s = avctx->priv_data;
00171 
00172     s->avctx = avctx;
00173 
00174     if (avctx->width%16 || avctx->height%16) {
00175          av_log_ask_for_sample(avctx, "dimensions not being a multiple of 16 are unsupported\n");
00176          return AVERROR_PATCHWELCOME;
00177     }
00178 
00179     s->width = avctx->width;
00180     s->height = avctx->height;
00181     avcodec_get_frame_defaults(&s->frames[0]);
00182     avcodec_get_frame_defaults(&s->frames[1]);
00183     s->last_frame    = &s->frames[0];
00184     s->current_frame = &s->frames[1];
00185     avctx->pix_fmt = AV_PIX_FMT_YUV444P;
00186 
00187     return 0;
00188 }
00189 
00190 static int roq_decode_frame(AVCodecContext *avctx,
00191                             void *data, int *got_frame,
00192                             AVPacket *avpkt)
00193 {
00194     const uint8_t *buf = avpkt->data;
00195     int buf_size = avpkt->size;
00196     RoqContext *s = avctx->priv_data;
00197     int copy= !s->current_frame->data[0];
00198     int ret;
00199 
00200     s->current_frame->reference = 3;
00201     if ((ret = avctx->reget_buffer(avctx, s->current_frame)) < 0) {
00202         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
00203         return ret;
00204     }
00205 
00206     if(copy)
00207         av_picture_copy((AVPicture*)s->current_frame, (AVPicture*)s->last_frame,
00208                         avctx->pix_fmt, avctx->width, avctx->height);
00209 
00210     bytestream2_init(&s->gb, buf, buf_size);
00211     roqvideo_decode_frame(s);
00212 
00213     *got_frame      = 1;
00214     *(AVFrame*)data = *s->current_frame;
00215 
00216     /* shuffle frames */
00217     FFSWAP(AVFrame *, s->current_frame, s->last_frame);
00218 
00219     return buf_size;
00220 }
00221 
00222 static av_cold int roq_decode_end(AVCodecContext *avctx)
00223 {
00224     RoqContext *s = avctx->priv_data;
00225 
00226     /* release the last frame */
00227     if (s->last_frame->data[0])
00228         avctx->release_buffer(avctx, s->last_frame);
00229     if (s->current_frame->data[0])
00230         avctx->release_buffer(avctx, s->current_frame);
00231 
00232     return 0;
00233 }
00234 
00235 AVCodec ff_roq_decoder = {
00236     .name           = "roqvideo",
00237     .type           = AVMEDIA_TYPE_VIDEO,
00238     .id             = AV_CODEC_ID_ROQ,
00239     .priv_data_size = sizeof(RoqContext),
00240     .init           = roq_decode_init,
00241     .close          = roq_decode_end,
00242     .decode         = roq_decode_frame,
00243     .capabilities   = CODEC_CAP_DR1,
00244     .long_name      = NULL_IF_CONFIG_SMALL("id RoQ video"),
00245 };