Libav
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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, AVPacket *avpkt) 00071 { 00072 const uint8_t *buf = avpkt->data; 00073 int buf_size = avpkt->size; 00074 CamtasiaContext * const c = avctx->priv_data; 00075 const unsigned char *encoded = buf; 00076 unsigned char *outptr; 00077 int zret; // Zlib return code 00078 int len = buf_size; 00079 00080 if(c->pic.data[0]) 00081 avctx->release_buffer(avctx, &c->pic); 00082 00083 c->pic.reference = 1; 00084 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID; 00085 if(avctx->get_buffer(avctx, &c->pic) < 0){ 00086 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00087 return -1; 00088 } 00089 00090 outptr = c->pic.data[0]; // Output image pointer 00091 00092 zret = inflateReset(&(c->zstream)); 00093 if (zret != Z_OK) { 00094 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret); 00095 return -1; 00096 } 00097 c->zstream.next_in = encoded; 00098 c->zstream.avail_in = len; 00099 c->zstream.next_out = c->decomp_buf; 00100 c->zstream.avail_out = c->decomp_size; 00101 zret = inflate(&(c->zstream), Z_FINISH); 00102 // Z_DATA_ERROR means empty picture 00103 if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) { 00104 av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret); 00105 return -1; 00106 } 00107 00108 00109 if(zret != Z_DATA_ERROR) 00110 ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, c->decomp_buf, c->decomp_size - c->zstream.avail_out); 00111 00112 /* make the palette available on the way out */ 00113 if (c->avctx->pix_fmt == PIX_FMT_PAL8) { 00114 memcpy(c->pic.data[1], c->avctx->palctrl->palette, AVPALETTE_SIZE); 00115 if (c->avctx->palctrl->palette_changed) { 00116 c->pic.palette_has_changed = 1; 00117 c->avctx->palctrl->palette_changed = 0; 00118 } 00119 } 00120 00121 *data_size = sizeof(AVFrame); 00122 *(AVFrame*)data = c->pic; 00123 00124 /* always report that the buffer was completely consumed */ 00125 return buf_size; 00126 } 00127 00128 00129 00130 /* 00131 * 00132 * Init tscc decoder 00133 * 00134 */ 00135 static av_cold int decode_init(AVCodecContext *avctx) 00136 { 00137 CamtasiaContext * const c = avctx->priv_data; 00138 int zret; // Zlib return code 00139 00140 c->avctx = avctx; 00141 00142 c->height = avctx->height; 00143 00144 // Needed if zlib unused or init aborted before inflateInit 00145 memset(&(c->zstream), 0, sizeof(z_stream)); 00146 switch(avctx->bits_per_coded_sample){ 00147 case 8: avctx->pix_fmt = PIX_FMT_PAL8; break; 00148 case 16: avctx->pix_fmt = PIX_FMT_RGB555; break; 00149 case 24: 00150 avctx->pix_fmt = PIX_FMT_BGR24; 00151 break; 00152 case 32: avctx->pix_fmt = PIX_FMT_RGB32; break; 00153 default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample); 00154 return -1; 00155 } 00156 c->bpp = avctx->bits_per_coded_sample; 00157 // buffer size for RLE 'best' case when 2-byte code preceeds each pixel and there may be padding after it too 00158 c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2; 00159 00160 /* Allocate decompression buffer */ 00161 if (c->decomp_size) { 00162 if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) { 00163 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); 00164 return 1; 00165 } 00166 } 00167 00168 c->zstream.zalloc = Z_NULL; 00169 c->zstream.zfree = Z_NULL; 00170 c->zstream.opaque = Z_NULL; 00171 zret = inflateInit(&(c->zstream)); 00172 if (zret != Z_OK) { 00173 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret); 00174 return 1; 00175 } 00176 00177 return 0; 00178 } 00179 00180 00181 00182 /* 00183 * 00184 * Uninit tscc decoder 00185 * 00186 */ 00187 static av_cold int decode_end(AVCodecContext *avctx) 00188 { 00189 CamtasiaContext * const c = avctx->priv_data; 00190 00191 av_freep(&c->decomp_buf); 00192 00193 if (c->pic.data[0]) 00194 avctx->release_buffer(avctx, &c->pic); 00195 inflateEnd(&(c->zstream)); 00196 00197 return 0; 00198 } 00199 00200 AVCodec tscc_decoder = { 00201 "camtasia", 00202 AVMEDIA_TYPE_VIDEO, 00203 CODEC_ID_TSCC, 00204 sizeof(CamtasiaContext), 00205 decode_init, 00206 NULL, 00207 decode_end, 00208 decode_frame, 00209 CODEC_CAP_DR1, 00210 .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"), 00211 }; 00212