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 #if 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 #if !HAVE_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                         AVPacket *avpkt) {
 139     const uint8_t *buf = avpkt->data;
 140     int buf_size = avpkt->size;
 141     CamStudioContext *c = avctx->priv_data;
 142     AVFrame *picture = data;
 143
 144     if (buf_size < 2) {
 145         av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
 146         return -1;
 147     }
 148
 149     if (c->pic.data[0])
 150         avctx->release_buffer(avctx, &c->pic);
 151     c->pic.reference = 1;
 152     c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE |
 153                           FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 154     if (avctx->get_buffer(avctx, &c->pic) < 0) {
 155         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 156         return -1;
 157     }
 158
 159     // decompress data
 160     switch ((buf[0] >> 1) & 7) {
 161         case 0: { // lzo compression
 162             int outlen = c->decomp_size, inlen = buf_size - 2;
 163             if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen))
 164                 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
 165             break;
 166         }
 167         case 1: { // zlib compression
 168 #if CONFIG_ZLIB
 169             unsigned long dlen = c->decomp_size;
 170             if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK)
 171                 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
 172             break;
 173 #else
 174             av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
 175             return -1;
 176 #endif
 177         }
 178         default:
 179             av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
 180             return -1;
 181     }
 182
 183     // flip upside down, add difference frame
 184     if (buf[0] & 1) { // keyframe
 185         c->pic.pict_type = FF_I_TYPE;
 186         c->pic.key_frame = 1;
 187         switch (c->bpp) {
 188           case 16:
 189               copy_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
 190               break;
 191           case 32:
 192               copy_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
 193               break;
 194           default:
 195               copy_frame_default(&c->pic, c->decomp_buf, c->linelen, c->height);
 196         }
 197     } else {
 198         c->pic.pict_type = FF_P_TYPE;
 199         c->pic.key_frame = 0;
 200         switch (c->bpp) {
 201           case 16:
 202               add_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
 203               break;
 204           case 32:
 205               add_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
 206               break;
 207           default:
 208               add_frame_default(&c->pic, c->decomp_buf, c->linelen, c->height);
 209         }
 210     }
 211
 212     *picture = c->pic;
 213     *data_size = sizeof(AVFrame);
 214     return buf_size;
 215 }
 216
 217 static av_cold int decode_init(AVCodecContext *avctx) {
 218     CamStudioContext *c = avctx->priv_data;
 219     if (avcodec_check_dimensions(avctx, avctx->height, avctx->width) < 0) {
 220         return 1;
 221     }
 222     switch (avctx->bits_per_coded_sample) {
 223         case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
 224         case 24: avctx->pix_fmt = PIX_FMT_BGR24; break;
 225         case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
 226         default:
 227             av_log(avctx, AV_LOG_ERROR,
 228                    "CamStudio codec error: invalid depth %i bpp\n",
 229                    avctx->bits_per_coded_sample);
 230              return 1;
 231     }
 232     c->bpp = avctx->bits_per_coded_sample;
 233     c->pic.data[0] = NULL;
 234     c->linelen = avctx->width * avctx->bits_per_coded_sample / 8;
 235     c->height = avctx->height;
 236     c->decomp_size = c->height * c->linelen;
 237     c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING);
 238     if (!c->decomp_buf) {
 239         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 240         return 1;
 241     }
 242     return 0;
 243 }
 244
 245 static av_cold int decode_end(AVCodecContext *avctx) {
 246     CamStudioContext *c = avctx->priv_data;
 247     av_freep(&c->decomp_buf);
 248     if (c->pic.data[0])
 249         avctx->release_buffer(avctx, &c->pic);
 250     return 0;
 251 }
 252
 253 AVCodec cscd_decoder = {
 254     "camstudio",
 255     CODEC_TYPE_VIDEO,
 256     CODEC_ID_CSCD,
 257     sizeof(CamStudioContext),
 258     decode_init,
 259     NULL,
 260     decode_end,
 261     decode_frame,
 262     CODEC_CAP_DR1,
 263     .long_name = NULL_IF_CONFIG_SMALL("CamStudio"),
 264 };
 265