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libavcodec/8bps.c

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00001 /*
00002  * Quicktime Planar RGB (8BPS) Video Decoder
00003  * Copyright (C) 2003 Roberto Togni
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00034 #include <stdio.h>
00035 #include <stdlib.h>
00036 
00037 #include "libavutil/intreadwrite.h"
00038 #include "avcodec.h"
00039 
00040 
00041 static const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGB32, PIX_FMT_NONE};
00042 
00043 /*
00044  * Decoder context
00045  */
00046 typedef struct EightBpsContext {
00047 
00048         AVCodecContext *avctx;
00049         AVFrame pic;
00050 
00051         unsigned char planes;
00052         unsigned char planemap[4];
00053 } EightBpsContext;
00054 
00055 
00056 /*
00057  *
00058  * Decode a frame
00059  *
00060  */
00061 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
00062 {
00063         const uint8_t *buf = avpkt->data;
00064         int buf_size = avpkt->size;
00065         EightBpsContext * const c = avctx->priv_data;
00066         const unsigned char *encoded = buf;
00067         unsigned char *pixptr, *pixptr_end;
00068         unsigned int height = avctx->height; // Real image height
00069         unsigned int dlen, p, row;
00070         const unsigned char *lp, *dp;
00071         unsigned char count;
00072         unsigned int px_inc;
00073         unsigned int planes = c->planes;
00074         unsigned char *planemap = c->planemap;
00075 
00076         if(c->pic.data[0])
00077                 avctx->release_buffer(avctx, &c->pic);
00078 
00079         c->pic.reference = 0;
00080         c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
00081         if(avctx->get_buffer(avctx, &c->pic) < 0){
00082                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00083                 return -1;
00084         }
00085 
00086         /* Set data pointer after line lengths */
00087         dp = encoded + planes * (height << 1);
00088 
00089         /* Ignore alpha plane, don't know what to do with it */
00090         if (planes == 4)
00091                 planes--;
00092 
00093         px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGB32);
00094 
00095         for (p = 0; p < planes; p++) {
00096                 /* Lines length pointer for this plane */
00097                 lp = encoded + p * (height << 1);
00098 
00099                 /* Decode a plane */
00100                 for(row = 0; row < height; row++) {
00101                         pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
00102                         pixptr_end = pixptr + c->pic.linesize[0];
00103                         dlen = be2me_16(*(const unsigned short *)(lp+row*2));
00104                         /* Decode a row of this plane */
00105                         while(dlen > 0) {
00106                                 if(dp + 1 >= buf+buf_size) return -1;
00107                                 if ((count = *dp++) <= 127) {
00108                                         count++;
00109                                         dlen -= count + 1;
00110                                         if (pixptr + count * px_inc > pixptr_end)
00111                                             break;
00112                                         if(dp + count > buf+buf_size) return -1;
00113                                         while(count--) {
00114                                                 *pixptr = *dp++;
00115                                                 pixptr += px_inc;
00116                                         }
00117                                 } else {
00118                                         count = 257 - count;
00119                                         if (pixptr + count * px_inc > pixptr_end)
00120                                             break;
00121                                         while(count--) {
00122                                                 *pixptr = *dp;
00123                                                 pixptr += px_inc;
00124                                         }
00125                                         dp++;
00126                                         dlen -= 2;
00127                                 }
00128                         }
00129                 }
00130         }
00131 
00132         if (avctx->palctrl) {
00133                 memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
00134                 if (avctx->palctrl->palette_changed) {
00135                         c->pic.palette_has_changed = 1;
00136                         avctx->palctrl->palette_changed = 0;
00137                 } else
00138                         c->pic.palette_has_changed = 0;
00139         }
00140 
00141         *data_size = sizeof(AVFrame);
00142         *(AVFrame*)data = c->pic;
00143 
00144         /* always report that the buffer was completely consumed */
00145         return buf_size;
00146 }
00147 
00148 
00149 /*
00150  *
00151  * Init 8BPS decoder
00152  *
00153  */
00154 static av_cold int decode_init(AVCodecContext *avctx)
00155 {
00156         EightBpsContext * const c = avctx->priv_data;
00157 
00158         c->avctx = avctx;
00159 
00160         c->pic.data[0] = NULL;
00161 
00162         switch (avctx->bits_per_coded_sample) {
00163                 case 8:
00164                         avctx->pix_fmt = PIX_FMT_PAL8;
00165                         c->planes = 1;
00166                         c->planemap[0] = 0; // 1st plane is palette indexes
00167                         if (avctx->palctrl == NULL) {
00168                                 av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");
00169                                 return -1;
00170                         }
00171                         break;
00172                 case 24:
00173                         avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
00174                         c->planes = 3;
00175                         c->planemap[0] = 2; // 1st plane is red
00176                         c->planemap[1] = 1; // 2nd plane is green
00177                         c->planemap[2] = 0; // 3rd plane is blue
00178                         break;
00179                 case 32:
00180                         avctx->pix_fmt = PIX_FMT_RGB32;
00181                         c->planes = 4;
00182 #if HAVE_BIGENDIAN
00183                         c->planemap[0] = 1; // 1st plane is red
00184                         c->planemap[1] = 2; // 2nd plane is green
00185                         c->planemap[2] = 3; // 3rd plane is blue
00186                         c->planemap[3] = 0; // 4th plane is alpha???
00187 #else
00188                         c->planemap[0] = 2; // 1st plane is red
00189                         c->planemap[1] = 1; // 2nd plane is green
00190                         c->planemap[2] = 0; // 3rd plane is blue
00191                         c->planemap[3] = 3; // 4th plane is alpha???
00192 #endif
00193                         break;
00194                 default:
00195                         av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_coded_sample);
00196                         return -1;
00197         }
00198 
00199   return 0;
00200 }
00201 
00202 
00203 
00204 
00205 /*
00206  *
00207  * Uninit 8BPS decoder
00208  *
00209  */
00210 static av_cold int decode_end(AVCodecContext *avctx)
00211 {
00212         EightBpsContext * const c = avctx->priv_data;
00213 
00214         if (c->pic.data[0])
00215                 avctx->release_buffer(avctx, &c->pic);
00216 
00217         return 0;
00218 }
00219 
00220 
00221 
00222 AVCodec eightbps_decoder = {
00223         "8bps",
00224         AVMEDIA_TYPE_VIDEO,
00225         CODEC_ID_8BPS,
00226         sizeof(EightBpsContext),
00227         decode_init,
00228         NULL,
00229         decode_end,
00230         decode_frame,
00231         CODEC_CAP_DR1,
00232         .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
00233 };

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