Libav 0.7.1
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00001 /* 00002 * TechSmith Camtasia decoder 00003 * Copyright (c) 2004 Konstantin Shishkov 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 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 00064 uint32_t pal[256]; 00065 } CamtasiaContext; 00066 00067 /* 00068 * 00069 * Decode a frame 00070 * 00071 */ 00072 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) 00073 { 00074 const uint8_t *buf = avpkt->data; 00075 int buf_size = avpkt->size; 00076 CamtasiaContext * const c = avctx->priv_data; 00077 const unsigned char *encoded = buf; 00078 int zret; // Zlib return code 00079 int len = buf_size; 00080 00081 if(c->pic.data[0]) 00082 avctx->release_buffer(avctx, &c->pic); 00083 00084 c->pic.reference = 1; 00085 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID; 00086 if(avctx->get_buffer(avctx, &c->pic) < 0){ 00087 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00088 return -1; 00089 } 00090 00091 zret = inflateReset(&(c->zstream)); 00092 if (zret != Z_OK) { 00093 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret); 00094 return -1; 00095 } 00096 c->zstream.next_in = encoded; 00097 c->zstream.avail_in = len; 00098 c->zstream.next_out = c->decomp_buf; 00099 c->zstream.avail_out = c->decomp_size; 00100 zret = inflate(&(c->zstream), Z_FINISH); 00101 // Z_DATA_ERROR means empty picture 00102 if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) { 00103 av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret); 00104 return -1; 00105 } 00106 00107 00108 if(zret != Z_DATA_ERROR) 00109 ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, c->decomp_buf, c->decomp_size - c->zstream.avail_out); 00110 00111 /* make the palette available on the way out */ 00112 if (c->avctx->pix_fmt == PIX_FMT_PAL8) { 00113 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); 00114 00115 if (pal) { 00116 c->pic.palette_has_changed = 1; 00117 memcpy(c->pal, pal, AVPALETTE_SIZE); 00118 } 00119 memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE); 00120 } 00121 00122 *data_size = sizeof(AVFrame); 00123 *(AVFrame*)data = c->pic; 00124 00125 /* always report that the buffer was completely consumed */ 00126 return buf_size; 00127 } 00128 00129 00130 00131 /* 00132 * 00133 * Init tscc decoder 00134 * 00135 */ 00136 static av_cold int decode_init(AVCodecContext *avctx) 00137 { 00138 CamtasiaContext * const c = avctx->priv_data; 00139 int zret; // Zlib return code 00140 00141 c->avctx = avctx; 00142 00143 c->height = avctx->height; 00144 00145 // Needed if zlib unused or init aborted before inflateInit 00146 memset(&(c->zstream), 0, sizeof(z_stream)); 00147 switch(avctx->bits_per_coded_sample){ 00148 case 8: avctx->pix_fmt = PIX_FMT_PAL8; break; 00149 case 16: avctx->pix_fmt = PIX_FMT_RGB555; break; 00150 case 24: 00151 avctx->pix_fmt = PIX_FMT_BGR24; 00152 break; 00153 case 32: avctx->pix_fmt = PIX_FMT_RGB32; break; 00154 default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample); 00155 return -1; 00156 } 00157 c->bpp = avctx->bits_per_coded_sample; 00158 // buffer size for RLE 'best' case when 2-byte code preceeds each pixel and there may be padding after it too 00159 c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2; 00160 00161 /* Allocate decompression buffer */ 00162 if (c->decomp_size) { 00163 if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) { 00164 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); 00165 return 1; 00166 } 00167 } 00168 00169 c->zstream.zalloc = Z_NULL; 00170 c->zstream.zfree = Z_NULL; 00171 c->zstream.opaque = Z_NULL; 00172 zret = inflateInit(&(c->zstream)); 00173 if (zret != Z_OK) { 00174 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret); 00175 return 1; 00176 } 00177 00178 return 0; 00179 } 00180 00181 00182 00183 /* 00184 * 00185 * Uninit tscc decoder 00186 * 00187 */ 00188 static av_cold int decode_end(AVCodecContext *avctx) 00189 { 00190 CamtasiaContext * const c = avctx->priv_data; 00191 00192 av_freep(&c->decomp_buf); 00193 00194 if (c->pic.data[0]) 00195 avctx->release_buffer(avctx, &c->pic); 00196 inflateEnd(&(c->zstream)); 00197 00198 return 0; 00199 } 00200 00201 AVCodec ff_tscc_decoder = { 00202 "camtasia", 00203 AVMEDIA_TYPE_VIDEO, 00204 CODEC_ID_TSCC, 00205 sizeof(CamtasiaContext), 00206 decode_init, 00207 NULL, 00208 decode_end, 00209 decode_frame, 00210 CODEC_CAP_DR1, 00211 .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"), 00212 }; 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