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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 
00054         uint32_t pal[256];
00055 } EightBpsContext;
00056 
00057 
00058 /*
00059  *
00060  * Decode a frame
00061  *
00062  */
00063 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
00064 {
00065         const uint8_t *buf = avpkt->data;
00066         int buf_size = avpkt->size;
00067         EightBpsContext * const c = avctx->priv_data;
00068         const unsigned char *encoded = buf;
00069         unsigned char *pixptr, *pixptr_end;
00070         unsigned int height = avctx->height; // Real image height
00071         unsigned int dlen, p, row;
00072         const unsigned char *lp, *dp;
00073         unsigned char count;
00074         unsigned int planes = c->planes;
00075         unsigned char *planemap = c->planemap;
00076 
00077         if(c->pic.data[0])
00078                 avctx->release_buffer(avctx, &c->pic);
00079 
00080         c->pic.reference = 0;
00081         c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
00082         if(avctx->get_buffer(avctx, &c->pic) < 0){
00083                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00084                 return -1;
00085         }
00086 
00087         /* Set data pointer after line lengths */
00088         dp = encoded + planes * (height << 1);
00089 
00090         for (p = 0; p < planes; p++) {
00091                 /* Lines length pointer for this plane */
00092                 lp = encoded + p * (height << 1);
00093 
00094                 /* Decode a plane */
00095                 for(row = 0; row < height; row++) {
00096                         pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
00097                         pixptr_end = pixptr + c->pic.linesize[0];
00098                         dlen = av_be2ne16(*(const unsigned short *)(lp+row*2));
00099                         /* Decode a row of this plane */
00100                         while(dlen > 0) {
00101                                 if(dp + 1 >= buf+buf_size) return -1;
00102                                 if ((count = *dp++) <= 127) {
00103                                         count++;
00104                                         dlen -= count + 1;
00105                                         if (pixptr + count * planes > pixptr_end)
00106                                             break;
00107                                         if(dp + count > buf+buf_size) return -1;
00108                                         while(count--) {
00109                                                 *pixptr = *dp++;
00110                                                 pixptr += planes;
00111                                         }
00112                                 } else {
00113                                         count = 257 - count;
00114                                         if (pixptr + count * planes > pixptr_end)
00115                                             break;
00116                                         while(count--) {
00117                                                 *pixptr = *dp;
00118                                                 pixptr += planes;
00119                                         }
00120                                         dp++;
00121                                         dlen -= 2;
00122                                 }
00123                         }
00124                 }
00125         }
00126 
00127         if (avctx->bits_per_coded_sample <= 8) {
00128                 const uint8_t *pal = av_packet_get_side_data(avpkt,
00129                                                              AV_PKT_DATA_PALETTE,
00130                                                              NULL);
00131                 if (pal) {
00132                         c->pic.palette_has_changed = 1;
00133                         memcpy(c->pal, pal, AVPALETTE_SIZE);
00134                 }
00135 
00136                 memcpy (c->pic.data[1], c->pal, AVPALETTE_SIZE);
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         avcodec_get_frame_defaults(&c->pic);
00159         c->pic.data[0] = NULL;
00160 
00161         switch (avctx->bits_per_coded_sample) {
00162                 case 8:
00163                         avctx->pix_fmt = PIX_FMT_PAL8;
00164                         c->planes = 1;
00165                         c->planemap[0] = 0; // 1st plane is palette indexes
00166                         break;
00167                 case 24:
00168                         avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
00169                         c->planes = 3;
00170                         c->planemap[0] = 2; // 1st plane is red
00171                         c->planemap[1] = 1; // 2nd plane is green
00172                         c->planemap[2] = 0; // 3rd plane is blue
00173                         break;
00174                 case 32:
00175                         avctx->pix_fmt = PIX_FMT_RGB32;
00176                         c->planes = 4;
00177 #if HAVE_BIGENDIAN
00178                         c->planemap[0] = 1; // 1st plane is red
00179                         c->planemap[1] = 2; // 2nd plane is green
00180                         c->planemap[2] = 3; // 3rd plane is blue
00181                         c->planemap[3] = 0; // 4th plane is alpha
00182 #else
00183                         c->planemap[0] = 2; // 1st plane is red
00184                         c->planemap[1] = 1; // 2nd plane is green
00185                         c->planemap[2] = 0; // 3rd plane is blue
00186                         c->planemap[3] = 3; // 4th plane is alpha
00187 #endif
00188                         break;
00189                 default:
00190                         av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_coded_sample);
00191                         return -1;
00192         }
00193 
00194   return 0;
00195 }
00196 
00197 
00198 
00199 
00200 /*
00201  *
00202  * Uninit 8BPS decoder
00203  *
00204  */
00205 static av_cold int decode_end(AVCodecContext *avctx)
00206 {
00207         EightBpsContext * const c = avctx->priv_data;
00208 
00209         if (c->pic.data[0])
00210                 avctx->release_buffer(avctx, &c->pic);
00211 
00212         return 0;
00213 }
00214 
00215 
00216 
00217 AVCodec ff_eightbps_decoder = {
00218     .name           = "8bps",
00219     .type           = AVMEDIA_TYPE_VIDEO,
00220     .id             = CODEC_ID_8BPS,
00221     .priv_data_size = sizeof(EightBpsContext),
00222     .init           = decode_init,
00223     .close          = decode_end,
00224     .decode         = decode_frame,
00225     .capabilities   = CODEC_CAP_DR1,
00226     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
00227 };
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