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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 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 precedes 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     .name           = "camtasia",
00203     .type           = AVMEDIA_TYPE_VIDEO,
00204     .id             = CODEC_ID_TSCC,
00205     .priv_data_size = sizeof(CamtasiaContext),
00206     .init           = decode_init,
00207     .close          = decode_end,
00208     .decode         = decode_frame,
00209     .capabilities   = CODEC_CAP_DR1,
00210     .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
00211 };
00212 
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