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libavcodec/cscd.c

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00001 /*
00002  * CamStudio decoder
00003  * Copyright (c) 2006 Reimar Doeffinger
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 #include <stdio.h>
00022 #include <stdlib.h>
00023 
00024 #include "avcodec.h"
00025 
00026 #if CONFIG_ZLIB
00027 #include <zlib.h>
00028 #endif
00029 #include "libavutil/lzo.h"
00030 
00031 typedef struct {
00032     AVFrame pic;
00033     int linelen, height, bpp;
00034     unsigned int decomp_size;
00035     unsigned char* decomp_buf;
00036 } CamStudioContext;
00037 
00038 static void copy_frame_default(AVFrame *f, const uint8_t *src, int src_stride,
00039                                int linelen, int height) {
00040     int i;
00041     uint8_t *dst = f->data[0];
00042     dst += (height - 1) * f->linesize[0];
00043     for (i = height; i; i--) {
00044         memcpy(dst, src, linelen);
00045         src += src_stride;
00046         dst -= f->linesize[0];
00047     }
00048 }
00049 
00050 static void add_frame_default(AVFrame *f, const uint8_t *src, int src_stride,
00051                               int linelen, int height) {
00052     int i, j;
00053     uint8_t *dst = f->data[0];
00054     dst += (height - 1) * f->linesize[0];
00055     for (i = height; i; i--) {
00056         for (j = linelen; j; j--)
00057             *dst++ += *src++;
00058         src += src_stride - linelen;
00059         dst -= f->linesize[0] + linelen;
00060     }
00061 }
00062 
00063 #if !HAVE_BIGENDIAN
00064 #define copy_frame_16(f, s, l, h) copy_frame_default(f, s, l, l, h)
00065 #define copy_frame_32(f, s, l, h) copy_frame_default(f, s, l, l, h)
00066 #define add_frame_16(f, s, l, h) add_frame_default(f, s, l, l, h)
00067 #define add_frame_32(f, s, l, h) add_frame_default(f, s, l, l, h)
00068 #else
00069 static void copy_frame_16(AVFrame *f, const uint8_t *src,
00070                           int linelen, int height) {
00071     int i, j;
00072     uint8_t *dst = f->data[0];
00073     dst += (height - 1) * f->linesize[0];
00074     for (i = height; i; i--) {
00075         for (j = linelen / 2; j; j--) {
00076           dst[0] = src[1];
00077           dst[1] = src[0];
00078           src += 2;
00079           dst += 2;
00080         }
00081         dst -= f->linesize[0] + linelen;
00082     }
00083 }
00084 
00085 static void copy_frame_32(AVFrame *f, const uint8_t *src,
00086                           int linelen, int height) {
00087     int i, j;
00088     uint8_t *dst = f->data[0];
00089     dst += (height - 1) * f->linesize[0];
00090     for (i = height; i; i--) {
00091         for (j = linelen / 4; j; j--) {
00092           dst[0] = src[3];
00093           dst[1] = src[2];
00094           dst[2] = src[1];
00095           dst[3] = src[0];
00096           src += 4;
00097           dst += 4;
00098         }
00099         dst -= f->linesize[0] + linelen;
00100     }
00101 }
00102 
00103 static void add_frame_16(AVFrame *f, const uint8_t *src,
00104                          int linelen, int height) {
00105     int i, j;
00106     uint8_t *dst = f->data[0];
00107     dst += (height - 1) * f->linesize[0];
00108     for (i = height; i; i--) {
00109         for (j = linelen / 2; j; j--) {
00110           dst[0] += src[1];
00111           dst[1] += src[0];
00112           src += 2;
00113           dst += 2;
00114         }
00115         dst -= f->linesize[0] + linelen;
00116     }
00117 }
00118 
00119 static void add_frame_32(AVFrame *f, const uint8_t *src,
00120                          int linelen, int height) {
00121     int i, j;
00122     uint8_t *dst = f->data[0];
00123     dst += (height - 1) * f->linesize[0];
00124     for (i = height; i; i--) {
00125         for (j = linelen / 4; j; j--) {
00126           dst[0] += src[3];
00127           dst[1] += src[2];
00128           dst[2] += src[1];
00129           dst[3] += src[0];
00130           src += 4;
00131           dst += 4;
00132         }
00133         dst -= f->linesize[0] + linelen;
00134     }
00135 }
00136 #endif
00137 
00138 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
00139                         AVPacket *avpkt) {
00140     const uint8_t *buf = avpkt->data;
00141     int buf_size = avpkt->size;
00142     CamStudioContext *c = avctx->priv_data;
00143     AVFrame *picture = data;
00144 
00145     if (buf_size < 2) {
00146         av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
00147         return -1;
00148     }
00149 
00150     if (c->pic.data[0])
00151         avctx->release_buffer(avctx, &c->pic);
00152     c->pic.reference = 1;
00153     c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE |
00154                           FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
00155     if (avctx->get_buffer(avctx, &c->pic) < 0) {
00156         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00157         return -1;
00158     }
00159 
00160     // decompress data
00161     switch ((buf[0] >> 1) & 7) {
00162         case 0: { // lzo compression
00163             int outlen = c->decomp_size, inlen = buf_size - 2;
00164             if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen))
00165                 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
00166             break;
00167         }
00168         case 1: { // zlib compression
00169 #if CONFIG_ZLIB
00170             unsigned long dlen = c->decomp_size;
00171             if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK)
00172                 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
00173             break;
00174 #else
00175             av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
00176             return -1;
00177 #endif
00178         }
00179         default:
00180             av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
00181             return -1;
00182     }
00183 
00184     // flip upside down, add difference frame
00185     if (buf[0] & 1) { // keyframe
00186         c->pic.pict_type = AV_PICTURE_TYPE_I;
00187         c->pic.key_frame = 1;
00188         switch (c->bpp) {
00189           case 16:
00190               copy_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
00191               break;
00192           case 32:
00193               copy_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
00194               break;
00195           default:
00196               copy_frame_default(&c->pic, c->decomp_buf, FFALIGN(c->linelen, 4),
00197                                  c->linelen, c->height);
00198         }
00199     } else {
00200         c->pic.pict_type = AV_PICTURE_TYPE_P;
00201         c->pic.key_frame = 0;
00202         switch (c->bpp) {
00203           case 16:
00204               add_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
00205               break;
00206           case 32:
00207               add_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
00208               break;
00209           default:
00210               add_frame_default(&c->pic, c->decomp_buf, FFALIGN(c->linelen, 4),
00211                                 c->linelen, c->height);
00212         }
00213     }
00214 
00215     *picture = c->pic;
00216     *data_size = sizeof(AVFrame);
00217     return buf_size;
00218 }
00219 
00220 static av_cold int decode_init(AVCodecContext *avctx) {
00221     CamStudioContext *c = avctx->priv_data;
00222     int stride;
00223     switch (avctx->bits_per_coded_sample) {
00224         case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
00225         case 24: avctx->pix_fmt = PIX_FMT_BGR24; break;
00226         case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
00227         default:
00228             av_log(avctx, AV_LOG_ERROR,
00229                    "CamStudio codec error: invalid depth %i bpp\n",
00230                    avctx->bits_per_coded_sample);
00231             return AVERROR_INVALIDDATA;
00232     }
00233     c->bpp = avctx->bits_per_coded_sample;
00234     c->pic.data[0] = NULL;
00235     c->linelen = avctx->width * avctx->bits_per_coded_sample / 8;
00236     c->height = avctx->height;
00237     stride = c->linelen;
00238     if (avctx->bits_per_coded_sample == 24)
00239         stride = FFALIGN(stride, 4);
00240     c->decomp_size = c->height * stride;
00241     c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING);
00242     if (!c->decomp_buf) {
00243         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
00244         return AVERROR(ENOMEM);
00245     }
00246     return 0;
00247 }
00248 
00249 static av_cold int decode_end(AVCodecContext *avctx) {
00250     CamStudioContext *c = avctx->priv_data;
00251     av_freep(&c->decomp_buf);
00252     if (c->pic.data[0])
00253         avctx->release_buffer(avctx, &c->pic);
00254     return 0;
00255 }
00256 
00257 AVCodec ff_cscd_decoder = {
00258     .name           = "camstudio",
00259     .type           = AVMEDIA_TYPE_VIDEO,
00260     .id             = CODEC_ID_CSCD,
00261     .priv_data_size = sizeof(CamStudioContext),
00262     .init           = decode_init,
00263     .close          = decode_end,
00264     .decode         = decode_frame,
00265     .capabilities   = CODEC_CAP_DR1,
00266     .long_name = NULL_IF_CONFIG_SMALL("CamStudio"),
00267 };
00268 
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