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libavcodec/tscc.c

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00001 /*
00002  * TechSmith Camtasia decoder
00003  * Copyright (c) 2004 Konstantin Shishkov
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00038 #include <stdio.h>
00039 #include <stdlib.h>
00040 
00041 #include "avcodec.h"
00042 #include "msrledec.h"
00043 
00044 #include <zlib.h>
00045 
00046 
00047 /*
00048  * Decoder context
00049  */
00050 typedef struct TsccContext {
00051 
00052     AVCodecContext *avctx;
00053     AVFrame pic;
00054 
00055     // Bits per pixel
00056     int bpp;
00057     // Decompressed data size
00058     unsigned int decomp_size;
00059     // Decompression buffer
00060     unsigned char* decomp_buf;
00061     int height;
00062     z_stream zstream;
00063 } CamtasiaContext;
00064 
00065 /*
00066  *
00067  * Decode a frame
00068  *
00069  */
00070 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
00071 {
00072     CamtasiaContext * const c = avctx->priv_data;
00073     const unsigned char *encoded = buf;
00074     unsigned char *outptr;
00075     int zret; // Zlib return code
00076     int len = buf_size;
00077 
00078     if(c->pic.data[0])
00079             avctx->release_buffer(avctx, &c->pic);
00080 
00081     c->pic.reference = 1;
00082     c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
00083     if(avctx->get_buffer(avctx, &c->pic) < 0){
00084         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00085         return -1;
00086     }
00087 
00088     outptr = c->pic.data[0]; // Output image pointer
00089 
00090     zret = inflateReset(&(c->zstream));
00091     if (zret != Z_OK) {
00092         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
00093         return -1;
00094     }
00095     c->zstream.next_in = encoded;
00096     c->zstream.avail_in = len;
00097     c->zstream.next_out = c->decomp_buf;
00098     c->zstream.avail_out = c->decomp_size;
00099     zret = inflate(&(c->zstream), Z_FINISH);
00100     // Z_DATA_ERROR means empty picture
00101     if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
00102         av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
00103         return -1;
00104     }
00105 
00106 
00107     if(zret != Z_DATA_ERROR)
00108         ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, c->decomp_buf, c->zstream.avail_out);
00109 
00110     /* make the palette available on the way out */
00111     if (c->avctx->pix_fmt == PIX_FMT_PAL8) {
00112         memcpy(c->pic.data[1], c->avctx->palctrl->palette, AVPALETTE_SIZE);
00113         if (c->avctx->palctrl->palette_changed) {
00114             c->pic.palette_has_changed = 1;
00115             c->avctx->palctrl->palette_changed = 0;
00116         }
00117     }
00118 
00119     *data_size = sizeof(AVFrame);
00120     *(AVFrame*)data = c->pic;
00121 
00122     /* always report that the buffer was completely consumed */
00123     return buf_size;
00124 }
00125 
00126 
00127 
00128 /*
00129  *
00130  * Init tscc decoder
00131  *
00132  */
00133 static av_cold int decode_init(AVCodecContext *avctx)
00134 {
00135     CamtasiaContext * const c = avctx->priv_data;
00136     int zret; // Zlib return code
00137 
00138     c->avctx = avctx;
00139 
00140     c->pic.data[0] = NULL;
00141     c->height = avctx->height;
00142 
00143     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
00144         return 1;
00145     }
00146 
00147     // Needed if zlib unused or init aborted before inflateInit
00148     memset(&(c->zstream), 0, sizeof(z_stream));
00149     switch(avctx->bits_per_coded_sample){
00150     case  8: avctx->pix_fmt = PIX_FMT_PAL8; break;
00151     case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
00152     case 24:
00153              avctx->pix_fmt = PIX_FMT_BGR24;
00154              break;
00155     case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
00156     default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
00157              return -1;
00158     }
00159     c->bpp = avctx->bits_per_coded_sample;
00160     c->decomp_size = (avctx->width * c->bpp + (avctx->width + 254) / 255 + 2) * avctx->height + 2;//RLE in the 'best' case
00161 
00162     /* Allocate decompression buffer */
00163     if (c->decomp_size) {
00164         if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
00165             av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
00166             return 1;
00167         }
00168     }
00169 
00170     c->zstream.zalloc = Z_NULL;
00171     c->zstream.zfree = Z_NULL;
00172     c->zstream.opaque = Z_NULL;
00173     zret = inflateInit(&(c->zstream));
00174     if (zret != Z_OK) {
00175         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
00176         return 1;
00177     }
00178 
00179     return 0;
00180 }
00181 
00182 
00183 
00184 /*
00185  *
00186  * Uninit tscc decoder
00187  *
00188  */
00189 static av_cold int decode_end(AVCodecContext *avctx)
00190 {
00191     CamtasiaContext * const c = avctx->priv_data;
00192 
00193     av_freep(&c->decomp_buf);
00194 
00195     if (c->pic.data[0])
00196         avctx->release_buffer(avctx, &c->pic);
00197     inflateEnd(&(c->zstream));
00198 
00199     return 0;
00200 }
00201 
00202 AVCodec tscc_decoder = {
00203         "camtasia",
00204         CODEC_TYPE_VIDEO,
00205         CODEC_ID_TSCC,
00206         sizeof(CamtasiaContext),
00207         decode_init,
00208         NULL,
00209         decode_end,
00210         decode_frame,
00211         CODEC_CAP_DR1,
00212         .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
00213 };
00214 

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