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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, const uint8_t *buf, int buf_size)
00062 {
00063         EightBpsContext * const c = avctx->priv_data;
00064         const unsigned char *encoded = buf;
00065         unsigned char *pixptr, *pixptr_end;
00066         unsigned int height = avctx->height; // Real image height
00067         unsigned int dlen, p, row;
00068         const unsigned char *lp, *dp;
00069         unsigned char count;
00070         unsigned int px_inc;
00071         unsigned int planes = c->planes;
00072         unsigned char *planemap = c->planemap;
00073 
00074         if(c->pic.data[0])
00075                 avctx->release_buffer(avctx, &c->pic);
00076 
00077         c->pic.reference = 0;
00078         c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
00079         if(avctx->get_buffer(avctx, &c->pic) < 0){
00080                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00081                 return -1;
00082         }
00083 
00084         /* Set data pointer after line lengths */
00085         dp = encoded + planes * (height << 1);
00086 
00087         /* Ignore alpha plane, don't know what to do with it */
00088         if (planes == 4)
00089                 planes--;
00090 
00091         px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGB32);
00092 
00093         for (p = 0; p < planes; p++) {
00094                 /* Lines length pointer for this plane */
00095                 lp = encoded + p * (height << 1);
00096 
00097                 /* Decode a plane */
00098                 for(row = 0; row < height; row++) {
00099                         pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
00100                         pixptr_end = pixptr + c->pic.linesize[0];
00101                         dlen = be2me_16(*(const unsigned short *)(lp+row*2));
00102                         /* Decode a row of this plane */
00103                         while(dlen > 0) {
00104                                 if(dp + 1 >= buf+buf_size) return -1;
00105                                 if ((count = *dp++) <= 127) {
00106                                         count++;
00107                                         dlen -= count + 1;
00108                                         if (pixptr + count * px_inc > pixptr_end)
00109                                             break;
00110                                         if(dp + count > buf+buf_size) return -1;
00111                                         while(count--) {
00112                                                 *pixptr = *dp++;
00113                                                 pixptr += px_inc;
00114                                         }
00115                                 } else {
00116                                         count = 257 - count;
00117                                         if (pixptr + count * px_inc > pixptr_end)
00118                                             break;
00119                                         while(count--) {
00120                                                 *pixptr = *dp;
00121                                                 pixptr += px_inc;
00122                                         }
00123                                         dp++;
00124                                         dlen -= 2;
00125                                 }
00126                         }
00127                 }
00128         }
00129 
00130         if (avctx->palctrl) {
00131                 memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
00132                 if (avctx->palctrl->palette_changed) {
00133                         c->pic.palette_has_changed = 1;
00134                         avctx->palctrl->palette_changed = 0;
00135                 } else
00136                         c->pic.palette_has_changed = 0;
00137         }
00138 
00139         *data_size = sizeof(AVFrame);
00140         *(AVFrame*)data = c->pic;
00141 
00142         /* always report that the buffer was completely consumed */
00143         return buf_size;
00144 }
00145 
00146 
00147 /*
00148  *
00149  * Init 8BPS decoder
00150  *
00151  */
00152 static av_cold int decode_init(AVCodecContext *avctx)
00153 {
00154         EightBpsContext * const c = avctx->priv_data;
00155 
00156         c->avctx = avctx;
00157 
00158         c->pic.data[0] = NULL;
00159 
00160     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
00161         return 1;
00162     }
00163 
00164         switch (avctx->bits_per_coded_sample) {
00165                 case 8:
00166                         avctx->pix_fmt = PIX_FMT_PAL8;
00167                         c->planes = 1;
00168                         c->planemap[0] = 0; // 1st plane is palette indexes
00169                         if (avctx->palctrl == NULL) {
00170                                 av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");
00171                                 return -1;
00172                         }
00173                         break;
00174                 case 24:
00175                         avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
00176                         c->planes = 3;
00177                         c->planemap[0] = 2; // 1st plane is red
00178                         c->planemap[1] = 1; // 2nd plane is green
00179                         c->planemap[2] = 0; // 3rd plane is blue
00180                         break;
00181                 case 32:
00182                         avctx->pix_fmt = PIX_FMT_RGB32;
00183                         c->planes = 4;
00184 #ifdef WORDS_BIGENDIAN
00185                         c->planemap[0] = 1; // 1st plane is red
00186                         c->planemap[1] = 2; // 2nd plane is green
00187                         c->planemap[2] = 3; // 3rd plane is blue
00188                         c->planemap[3] = 0; // 4th plane is alpha???
00189 #else
00190                         c->planemap[0] = 2; // 1st plane is red
00191                         c->planemap[1] = 1; // 2nd plane is green
00192                         c->planemap[2] = 0; // 3rd plane is blue
00193                         c->planemap[3] = 3; // 4th plane is alpha???
00194 #endif
00195                         break;
00196                 default:
00197                         av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_coded_sample);
00198                         return -1;
00199         }
00200 
00201   return 0;
00202 }
00203 
00204 
00205 
00206 
00207 /*
00208  *
00209  * Uninit 8BPS decoder
00210  *
00211  */
00212 static av_cold int decode_end(AVCodecContext *avctx)
00213 {
00214         EightBpsContext * const c = avctx->priv_data;
00215 
00216         if (c->pic.data[0])
00217                 avctx->release_buffer(avctx, &c->pic);
00218 
00219         return 0;
00220 }
00221 
00222 
00223 
00224 AVCodec eightbps_decoder = {
00225         "8bps",
00226         CODEC_TYPE_VIDEO,
00227         CODEC_ID_8BPS,
00228         sizeof(EightBpsContext),
00229         decode_init,
00230         NULL,
00231         decode_end,
00232         decode_frame,
00233         CODEC_CAP_DR1,
00234         .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
00235 };

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