Libav
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00001 /* 00002 * PC Paintbrush PCX (.pcx) image decoder 00003 * Copyright (c) 2007, 2008 Ivo van Poorten 00004 * 00005 * This decoder does not support CGA palettes. I am unable to find samples 00006 * and Netpbm cannot generate them. 00007 * 00008 * This file is part of FFmpeg. 00009 * 00010 * FFmpeg is free software; you can redistribute it and/or 00011 * modify it under the terms of the GNU Lesser General Public 00012 * License as published by the Free Software Foundation; either 00013 * version 2.1 of the License, or (at your option) any later version. 00014 * 00015 * FFmpeg is distributed in the hope that it will be useful, 00016 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00018 * Lesser General Public License for more details. 00019 * 00020 * You should have received a copy of the GNU Lesser General Public 00021 * License along with FFmpeg; if not, write to the Free Software 00022 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00023 */ 00024 00025 #include "avcodec.h" 00026 #include "bytestream.h" 00027 #include "get_bits.h" 00028 00029 typedef struct PCXContext { 00030 AVFrame picture; 00031 } PCXContext; 00032 00033 static av_cold int pcx_init(AVCodecContext *avctx) { 00034 PCXContext *s = avctx->priv_data; 00035 00036 avcodec_get_frame_defaults(&s->picture); 00037 avctx->coded_frame= &s->picture; 00038 00039 return 0; 00040 } 00041 00045 static const uint8_t *pcx_rle_decode(const uint8_t *src, uint8_t *dst, 00046 unsigned int bytes_per_scanline, int compressed) { 00047 unsigned int i = 0; 00048 unsigned char run, value; 00049 00050 if (compressed) { 00051 while (i<bytes_per_scanline) { 00052 run = 1; 00053 value = *src++; 00054 if (value >= 0xc0) { 00055 run = value & 0x3f; 00056 value = *src++; 00057 } 00058 while (i<bytes_per_scanline && run--) 00059 dst[i++] = value; 00060 } 00061 } else { 00062 memcpy(dst, src, bytes_per_scanline); 00063 src += bytes_per_scanline; 00064 } 00065 00066 return src; 00067 } 00068 00069 static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) { 00070 unsigned int i; 00071 00072 for (i=0; i<pallen; i++) 00073 *dst++ = bytestream_get_be24(src); 00074 if (pallen < 256) 00075 memset(dst, 0, (256 - pallen) * sizeof(*dst)); 00076 } 00077 00078 static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *data_size, 00079 AVPacket *avpkt) { 00080 const uint8_t *buf = avpkt->data; 00081 int buf_size = avpkt->size; 00082 PCXContext * const s = avctx->priv_data; 00083 AVFrame *picture = data; 00084 AVFrame * const p = &s->picture; 00085 int compressed, xmin, ymin, xmax, ymax; 00086 unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x, 00087 bytes_per_scanline; 00088 uint8_t *ptr; 00089 uint8_t const *bufstart = buf; 00090 00091 if (buf[0] != 0x0a || buf[1] > 5) { 00092 av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n"); 00093 return -1; 00094 } 00095 00096 compressed = buf[2]; 00097 xmin = AV_RL16(buf+ 4); 00098 ymin = AV_RL16(buf+ 6); 00099 xmax = AV_RL16(buf+ 8); 00100 ymax = AV_RL16(buf+10); 00101 00102 if (xmax < xmin || ymax < ymin) { 00103 av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n"); 00104 return -1; 00105 } 00106 00107 w = xmax - xmin + 1; 00108 h = ymax - ymin + 1; 00109 00110 bits_per_pixel = buf[3]; 00111 bytes_per_line = AV_RL16(buf+66); 00112 nplanes = buf[65]; 00113 bytes_per_scanline = nplanes * bytes_per_line; 00114 00115 if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) { 00116 av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n"); 00117 return -1; 00118 } 00119 00120 switch ((nplanes<<8) + bits_per_pixel) { 00121 case 0x0308: 00122 avctx->pix_fmt = PIX_FMT_RGB24; 00123 break; 00124 case 0x0108: 00125 case 0x0104: 00126 case 0x0102: 00127 case 0x0101: 00128 case 0x0401: 00129 case 0x0301: 00130 case 0x0201: 00131 avctx->pix_fmt = PIX_FMT_PAL8; 00132 break; 00133 default: 00134 av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n"); 00135 return -1; 00136 } 00137 00138 buf += 128; 00139 00140 if (p->data[0]) 00141 avctx->release_buffer(avctx, p); 00142 00143 if (avcodec_check_dimensions(avctx, w, h)) 00144 return -1; 00145 if (w != avctx->width || h != avctx->height) 00146 avcodec_set_dimensions(avctx, w, h); 00147 if (avctx->get_buffer(avctx, p) < 0) { 00148 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00149 return -1; 00150 } 00151 00152 p->pict_type = FF_I_TYPE; 00153 00154 ptr = p->data[0]; 00155 stride = p->linesize[0]; 00156 00157 if (nplanes == 3 && bits_per_pixel == 8) { 00158 uint8_t scanline[bytes_per_scanline]; 00159 00160 for (y=0; y<h; y++) { 00161 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed); 00162 00163 for (x=0; x<w; x++) { 00164 ptr[3*x ] = scanline[x ]; 00165 ptr[3*x+1] = scanline[x+ bytes_per_line ]; 00166 ptr[3*x+2] = scanline[x+(bytes_per_line<<1)]; 00167 } 00168 00169 ptr += stride; 00170 } 00171 00172 } else if (nplanes == 1 && bits_per_pixel == 8) { 00173 uint8_t scanline[bytes_per_scanline]; 00174 const uint8_t *palstart = bufstart + buf_size - 769; 00175 00176 for (y=0; y<h; y++, ptr+=stride) { 00177 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed); 00178 memcpy(ptr, scanline, w); 00179 } 00180 00181 if (buf != palstart) { 00182 av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n"); 00183 buf = palstart; 00184 } 00185 if (*buf++ != 12) { 00186 av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n"); 00187 return -1; 00188 } 00189 00190 } else if (nplanes == 1) { /* all packed formats, max. 16 colors */ 00191 uint8_t scanline[bytes_per_scanline]; 00192 GetBitContext s; 00193 00194 for (y=0; y<h; y++) { 00195 init_get_bits(&s, scanline, bytes_per_scanline<<3); 00196 00197 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed); 00198 00199 for (x=0; x<w; x++) 00200 ptr[x] = get_bits(&s, bits_per_pixel); 00201 ptr += stride; 00202 } 00203 00204 } else { /* planar, 4, 8 or 16 colors */ 00205 uint8_t scanline[bytes_per_scanline]; 00206 int i; 00207 00208 for (y=0; y<h; y++) { 00209 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline, compressed); 00210 00211 for (x=0; x<w; x++) { 00212 int m = 0x80 >> (x&7), v = 0; 00213 for (i=nplanes - 1; i>=0; i--) { 00214 v <<= 1; 00215 v += !!(scanline[i*bytes_per_line + (x>>3)] & m); 00216 } 00217 ptr[x] = v; 00218 } 00219 ptr += stride; 00220 } 00221 } 00222 00223 if (nplanes == 1 && bits_per_pixel == 8) { 00224 pcx_palette(&buf, (uint32_t *) p->data[1], 256); 00225 } else if (bits_per_pixel < 8) { 00226 const uint8_t *palette = bufstart+16; 00227 pcx_palette(&palette, (uint32_t *) p->data[1], 16); 00228 } 00229 00230 *picture = s->picture; 00231 *data_size = sizeof(AVFrame); 00232 00233 return buf - bufstart; 00234 } 00235 00236 static av_cold int pcx_end(AVCodecContext *avctx) { 00237 PCXContext *s = avctx->priv_data; 00238 00239 if(s->picture.data[0]) 00240 avctx->release_buffer(avctx, &s->picture); 00241 00242 return 0; 00243 } 00244 00245 AVCodec pcx_decoder = { 00246 "pcx", 00247 AVMEDIA_TYPE_VIDEO, 00248 CODEC_ID_PCX, 00249 sizeof(PCXContext), 00250 pcx_init, 00251 NULL, 00252 pcx_end, 00253 pcx_decode_frame, 00254 CODEC_CAP_DR1, 00255 NULL, 00256 .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"), 00257 };