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 "bitstream.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) { 00047 unsigned int i = 0; 00048 unsigned char run, value; 00049 00050 while (i<bytes_per_scanline) { 00051 run = 1; 00052 value = *src++; 00053 if (value >= 0xc0) { 00054 run = value & 0x3f; 00055 value = *src++; 00056 } 00057 while (i<bytes_per_scanline && run--) 00058 dst[i++] = value; 00059 } 00060 00061 return src; 00062 } 00063 00064 static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) { 00065 unsigned int i; 00066 00067 for (i=0; i<pallen; i++) 00068 *dst++ = bytestream_get_be24(src); 00069 memset(dst, 0, (256 - pallen) * sizeof(*dst)); 00070 } 00071 00072 static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *data_size, 00073 const uint8_t *buf, int buf_size) { 00074 PCXContext * const s = avctx->priv_data; 00075 AVFrame *picture = data; 00076 AVFrame * const p = &s->picture; 00077 int xmin, ymin, xmax, ymax; 00078 unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x, 00079 bytes_per_scanline; 00080 uint8_t *ptr; 00081 uint8_t const *bufstart = buf; 00082 00083 if (buf[0] != 0x0a || buf[1] > 5 || buf[1] == 1 || buf[2] != 1) { 00084 av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n"); 00085 return -1; 00086 } 00087 00088 xmin = AV_RL16(buf+ 4); 00089 ymin = AV_RL16(buf+ 6); 00090 xmax = AV_RL16(buf+ 8); 00091 ymax = AV_RL16(buf+10); 00092 00093 if (xmax < xmin || ymax < ymin) { 00094 av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n"); 00095 return -1; 00096 } 00097 00098 w = xmax - xmin + 1; 00099 h = ymax - ymin + 1; 00100 00101 bits_per_pixel = buf[3]; 00102 bytes_per_line = AV_RL16(buf+66); 00103 nplanes = buf[65]; 00104 bytes_per_scanline = nplanes * bytes_per_line; 00105 00106 if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) { 00107 av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n"); 00108 return -1; 00109 } 00110 00111 switch ((nplanes<<8) + bits_per_pixel) { 00112 case 0x0308: 00113 avctx->pix_fmt = PIX_FMT_RGB24; 00114 break; 00115 case 0x0108: 00116 case 0x0104: 00117 case 0x0102: 00118 case 0x0101: 00119 case 0x0401: 00120 case 0x0301: 00121 case 0x0201: 00122 avctx->pix_fmt = PIX_FMT_PAL8; 00123 break; 00124 default: 00125 av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n"); 00126 return -1; 00127 } 00128 00129 buf += 128; 00130 00131 if (p->data[0]) 00132 avctx->release_buffer(avctx, p); 00133 00134 if (avcodec_check_dimensions(avctx, w, h)) 00135 return -1; 00136 if (w != avctx->width || h != avctx->height) 00137 avcodec_set_dimensions(avctx, w, h); 00138 if (avctx->get_buffer(avctx, p) < 0) { 00139 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00140 return -1; 00141 } 00142 00143 p->pict_type = FF_I_TYPE; 00144 00145 ptr = p->data[0]; 00146 stride = p->linesize[0]; 00147 00148 if (nplanes == 3 && bits_per_pixel == 8) { 00149 uint8_t scanline[bytes_per_scanline]; 00150 00151 for (y=0; y<h; y++) { 00152 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline); 00153 00154 for (x=0; x<w; x++) { 00155 ptr[3*x ] = scanline[x ]; 00156 ptr[3*x+1] = scanline[x+ bytes_per_line ]; 00157 ptr[3*x+2] = scanline[x+(bytes_per_line<<1)]; 00158 } 00159 00160 ptr += stride; 00161 } 00162 00163 } else if (nplanes == 1 && bits_per_pixel == 8) { 00164 uint8_t scanline[bytes_per_scanline]; 00165 const uint8_t *palstart = bufstart + buf_size - 769; 00166 00167 for (y=0; y<h; y++, ptr+=stride) { 00168 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline); 00169 memcpy(ptr, scanline, w); 00170 } 00171 00172 if (buf != palstart) { 00173 av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n"); 00174 buf = palstart; 00175 } 00176 if (*buf++ != 12) { 00177 av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n"); 00178 return -1; 00179 } 00180 00181 } else if (nplanes == 1) { /* all packed formats, max. 16 colors */ 00182 uint8_t scanline[bytes_per_scanline]; 00183 GetBitContext s; 00184 00185 for (y=0; y<h; y++) { 00186 init_get_bits(&s, scanline, bytes_per_scanline<<3); 00187 00188 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline); 00189 00190 for (x=0; x<w; x++) 00191 ptr[x] = get_bits(&s, bits_per_pixel); 00192 ptr += stride; 00193 } 00194 00195 } else { /* planar, 4, 8 or 16 colors */ 00196 uint8_t scanline[bytes_per_scanline]; 00197 int i; 00198 00199 for (y=0; y<h; y++) { 00200 buf = pcx_rle_decode(buf, scanline, bytes_per_scanline); 00201 00202 for (x=0; x<w; x++) { 00203 int m = 0x80 >> (x&7), v = 0; 00204 for (i=nplanes - 1; i>=0; i--) { 00205 v <<= 1; 00206 v += !!(scanline[i*bytes_per_line + (x>>3)] & m); 00207 } 00208 ptr[x] = v; 00209 } 00210 ptr += stride; 00211 } 00212 } 00213 00214 if (nplanes == 1 && bits_per_pixel == 8) { 00215 pcx_palette(&buf, (uint32_t *) p->data[1], 256); 00216 } else if (bits_per_pixel < 8) { 00217 const uint8_t *palette = bufstart+16; 00218 pcx_palette(&palette, (uint32_t *) p->data[1], 16); 00219 } 00220 00221 *picture = s->picture; 00222 *data_size = sizeof(AVFrame); 00223 00224 return buf - bufstart; 00225 } 00226 00227 static av_cold int pcx_end(AVCodecContext *avctx) { 00228 PCXContext *s = avctx->priv_data; 00229 00230 if(s->picture.data[0]) 00231 avctx->release_buffer(avctx, &s->picture); 00232 00233 return 0; 00234 } 00235 00236 AVCodec pcx_decoder = { 00237 "pcx", 00238 CODEC_TYPE_VIDEO, 00239 CODEC_ID_PCX, 00240 sizeof(PCXContext), 00241 pcx_init, 00242 NULL, 00243 pcx_end, 00244 pcx_decode_frame, 00245 0, 00246 NULL, 00247 .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"), 00248 };