libavcodec/cscd.c

   1 /*
   2  * CamStudio decoder
   3  * Copyright (c) 2006 Reimar Doeffinger
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23
  24 #include "avcodec.h"
  25
  26 #ifdef CONFIG_ZLIB
  27 #include <zlib.h>
  28 #endif
  29 #include "libavutil/lzo.h"
  30
  31 typedef struct {
  32     AVFrame pic;
  33     int linelen, height, bpp;
  34     unsigned int decomp_size;
  35     unsigned char* decomp_buf;
  36 } CamStudioContext;
  37
  38 static void copy_frame_default(AVFrame *f, const uint8_t *src,
  39                                int linelen, int height) {
  40     int i;
  41     uint8_t *dst = f->data[0];
  42     dst += (height - 1) * f->linesize[0];
  43     for (i = height; i; i--) {
  44         memcpy(dst, src, linelen);
  45         src += linelen;
  46         dst -= f->linesize[0];
  47     }
  48 }
  49
  50 static void add_frame_default(AVFrame *f, const uint8_t *src,
  51                               int linelen, int height) {
  52     int i, j;
  53     uint8_t *dst = f->data[0];
  54     dst += (height - 1) * f->linesize[0];
  55     for (i = height; i; i--) {
  56         for (j = linelen; j; j--)
  57             *dst++ += *src++;
  58         dst -= f->linesize[0] + linelen;
  59     }
  60 }
  61
  62 #ifndef WORDS_BIGENDIAN
  63 #define copy_frame_16 copy_frame_default
  64 #define copy_frame_32 copy_frame_default
  65 #define add_frame_16 add_frame_default
  66 #define add_frame_32 add_frame_default
  67 #else
  68 static void copy_frame_16(AVFrame *f, const uint8_t *src,
  69                           int linelen, int height) {
  70     int i, j;
  71     uint8_t *dst = f->data[0];
  72     dst += (height - 1) * f->linesize[0];
  73     for (i = height; i; i--) {
  74         for (j = linelen / 2; j; j--) {
  75           dst[0] = src[1];
  76           dst[1] = src[0];
  77           src += 2;
  78           dst += 2;
  79         }
  80         dst -= f->linesize[0] + linelen;
  81     }
  82 }
  83
  84 static void copy_frame_32(AVFrame *f, const uint8_t *src,
  85                           int linelen, int height) {
  86     int i, j;
  87     uint8_t *dst = f->data[0];
  88     dst += (height - 1) * f->linesize[0];
  89     for (i = height; i; i--) {
  90         for (j = linelen / 4; j; j--) {
  91           dst[0] = src[3];
  92           dst[1] = src[2];
  93           dst[2] = src[1];
  94           dst[3] = src[0];
  95           src += 4;
  96           dst += 4;
  97         }
  98         dst -= f->linesize[0] + linelen;
  99     }
 100 }
 101
 102 static void add_frame_16(AVFrame *f, const uint8_t *src,
 103                          int linelen, int height) {
 104     int i, j;
 105     uint8_t *dst = f->data[0];
 106     dst += (height - 1) * f->linesize[0];
 107     for (i = height; i; i--) {
 108         for (j = linelen / 2; j; j--) {
 109           dst[0] += src[1];
 110           dst[1] += src[0];
 111           src += 2;
 112           dst += 2;
 113         }
 114         dst -= f->linesize[0] + linelen;
 115     }
 116 }
 117
 118 static void add_frame_32(AVFrame *f, const uint8_t *src,
 119                          int linelen, int height) {
 120     int i, j;
 121     uint8_t *dst = f->data[0];
 122     dst += (height - 1) * f->linesize[0];
 123     for (i = height; i; i--) {
 124         for (j = linelen / 4; j; j--) {
 125           dst[0] += src[3];
 126           dst[1] += src[2];
 127           dst[2] += src[1];
 128           dst[3] += src[0];
 129           src += 4;
 130           dst += 4;
 131         }
 132         dst -= f->linesize[0] + linelen;
 133     }
 134 }
 135 #endif
 136
 137 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
 138                         const uint8_t *buf, int buf_size) {
 139     CamStudioContext *c = avctx->priv_data;
 140     AVFrame *picture = data;
 141
 142     if (buf_size < 2) {
 143         av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
 144         return -1;
 145     }
 146
 147     if (c->pic.data[0])
 148         avctx->release_buffer(avctx, &c->pic);
 149     c->pic.reference = 1;
 150     c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE |
 151                           FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 152     if (avctx->get_buffer(avctx, &c->pic) < 0) {
 153         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 154         return -1;
 155     }
 156
 157     // decompress data
 158     switch ((buf[0] >> 1) & 7) {
 159         case 0: { // lzo compression
 160             int outlen = c->decomp_size, inlen = buf_size - 2;
 161             if (lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen))
 162                 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
 163             break;
 164         }
 165         case 1: { // zlib compression
 166 #ifdef CONFIG_ZLIB
 167             unsigned long dlen = c->decomp_size;
 168             if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK)
 169                 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
 170             break;
 171 #else
 172             av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
 173             return -1;
 174 #endif
 175         }
 176         default:
 177             av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
 178             return -1;
 179     }
 180
 181     // flip upside down, add difference frame
 182     if (buf[0] & 1) { // keyframe
 183         c->pic.pict_type = FF_I_TYPE;
 184         c->pic.key_frame = 1;
 185         switch (c->bpp) {
 186           case 16:
 187               copy_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
 188               break;
 189           case 32:
 190               copy_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
 191               break;
 192           default:
 193               copy_frame_default(&c->pic, c->decomp_buf, c->linelen, c->height);
 194         }
 195     } else {
 196         c->pic.pict_type = FF_P_TYPE;
 197         c->pic.key_frame = 0;
 198         switch (c->bpp) {
 199           case 16:
 200               add_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
 201               break;
 202           case 32:
 203               add_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
 204               break;
 205           default:
 206               add_frame_default(&c->pic, c->decomp_buf, c->linelen, c->height);
 207         }
 208     }
 209
 210     *picture = c->pic;
 211     *data_size = sizeof(AVFrame);
 212     return buf_size;
 213 }
 214
 215 static av_cold int decode_init(AVCodecContext *avctx) {
 216     CamStudioContext *c = avctx->priv_data;
 217     if (avcodec_check_dimensions(avctx, avctx->height, avctx->width) < 0) {
 218         return 1;
 219     }
 220     switch (avctx->bits_per_sample) {
 221         case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
 222         case 24: avctx->pix_fmt = PIX_FMT_BGR24; break;
 223         case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
 224         default:
 225             av_log(avctx, AV_LOG_ERROR,
 226                    "CamStudio codec error: invalid depth %i bpp\n",
 227                    avctx->bits_per_sample);
 228              return 1;
 229     }
 230     c->bpp = avctx->bits_per_sample;
 231     c->pic.data[0] = NULL;
 232     c->linelen = avctx->width * avctx->bits_per_sample / 8;
 233     c->height = avctx->height;
 234     c->decomp_size = c->height * c->linelen;
 235     c->decomp_buf = av_malloc(c->decomp_size + LZO_OUTPUT_PADDING);
 236     if (!c->decomp_buf) {
 237         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 238         return 1;
 239     }
 240     return 0;
 241 }
 242
 243 static av_cold int decode_end(AVCodecContext *avctx) {
 244     CamStudioContext *c = avctx->priv_data;
 245     av_freep(&c->decomp_buf);
 246     if (c->pic.data[0])
 247         avctx->release_buffer(avctx, &c->pic);
 248     return 0;
 249 }
 250
 251 AVCodec cscd_decoder = {
 252     "camstudio",
 253     CODEC_TYPE_VIDEO,
 254     CODEC_ID_CSCD,
 255     sizeof(CamStudioContext),
 256     decode_init,
 257     NULL,
 258     decode_end,
 259     decode_frame,
 260     CODEC_CAP_DR1,
 261     .long_name = "CamStudio",
 262 };
 263