1/* 2 * TechSmith Camtasia decoder 3 * Copyright (c) 2004 Konstantin Shishkov 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * TechSmith Camtasia decoder 25 * 26 * Fourcc: TSCC 27 * 28 * Codec is very simple: 29 * it codes picture (picture difference, really) 30 * with algorithm almost identical to Windows RLE8, 31 * only without padding and with greater pixel sizes, 32 * then this coded picture is packed with ZLib 33 * 34 * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested 35 * 36 */ 37 38#include <stdio.h> 39#include <stdlib.h> 40 41#include "avcodec.h" 42#include "msrledec.h" 43 44#include <zlib.h> 45 46 47/* 48 * Decoder context 49 */ 50typedef struct TsccContext { 51 52 AVCodecContext *avctx; 53 AVFrame pic; 54 55 // Bits per pixel 56 int bpp; 57 // Decompressed data size 58 unsigned int decomp_size; 59 // Decompression buffer 60 unsigned char* decomp_buf; 61 int height; 62 z_stream zstream; 63} CamtasiaContext; 64 65/* 66 * 67 * Decode a frame 68 * 69 */ 70static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) 71{ 72 const uint8_t *buf = avpkt->data; 73 int buf_size = avpkt->size; 74 CamtasiaContext * const c = avctx->priv_data; 75 const unsigned char *encoded = buf; 76 unsigned char *outptr; 77 int zret; // Zlib return code 78 int len = buf_size; 79 80 if(c->pic.data[0]) 81 avctx->release_buffer(avctx, &c->pic); 82 83 c->pic.reference = 1; 84 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID; 85 if(avctx->get_buffer(avctx, &c->pic) < 0){ 86 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 87 return -1; 88 } 89 90 outptr = c->pic.data[0]; // Output image pointer 91 92 zret = inflateReset(&(c->zstream)); 93 if (zret != Z_OK) { 94 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret); 95 return -1; 96 } 97 c->zstream.next_in = encoded; 98 c->zstream.avail_in = len; 99 c->zstream.next_out = c->decomp_buf; 100 c->zstream.avail_out = c->decomp_size; 101 zret = inflate(&(c->zstream), Z_FINISH); 102 // Z_DATA_ERROR means empty picture 103 if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) { 104 av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret); 105 return -1; 106 } 107 108 109 if(zret != Z_DATA_ERROR) 110 ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, c->decomp_buf, c->decomp_size - c->zstream.avail_out); 111 112 /* make the palette available on the way out */ 113 if (c->avctx->pix_fmt == PIX_FMT_PAL8) { 114 memcpy(c->pic.data[1], c->avctx->palctrl->palette, AVPALETTE_SIZE); 115 if (c->avctx->palctrl->palette_changed) { 116 c->pic.palette_has_changed = 1; 117 c->avctx->palctrl->palette_changed = 0; 118 } 119 } 120 121 *data_size = sizeof(AVFrame); 122 *(AVFrame*)data = c->pic; 123 124 /* always report that the buffer was completely consumed */ 125 return buf_size; 126} 127 128 129 130/* 131 * 132 * Init tscc decoder 133 * 134 */ 135static av_cold int decode_init(AVCodecContext *avctx) 136{ 137 CamtasiaContext * const c = avctx->priv_data; 138 int zret; // Zlib return code 139 140 c->avctx = avctx; 141 142 c->height = avctx->height; 143 144 // Needed if zlib unused or init aborted before inflateInit 145 memset(&(c->zstream), 0, sizeof(z_stream)); 146 switch(avctx->bits_per_coded_sample){ 147 case 8: avctx->pix_fmt = PIX_FMT_PAL8; break; 148 case 16: avctx->pix_fmt = PIX_FMT_RGB555; break; 149 case 24: 150 avctx->pix_fmt = PIX_FMT_BGR24; 151 break; 152 case 32: avctx->pix_fmt = PIX_FMT_RGB32; break; 153 default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample); 154 return -1; 155 } 156 c->bpp = avctx->bits_per_coded_sample; 157 // buffer size for RLE 'best' case when 2-byte code preceeds each pixel and there may be padding after it too 158 c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2; 159 160 /* Allocate decompression buffer */ 161 if (c->decomp_size) { 162 if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) { 163 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); 164 return 1; 165 } 166 } 167 168 c->zstream.zalloc = Z_NULL; 169 c->zstream.zfree = Z_NULL; 170 c->zstream.opaque = Z_NULL; 171 zret = inflateInit(&(c->zstream)); 172 if (zret != Z_OK) { 173 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret); 174 return 1; 175 } 176 177 return 0; 178} 179 180 181 182/* 183 * 184 * Uninit tscc decoder 185 * 186 */ 187static av_cold int decode_end(AVCodecContext *avctx) 188{ 189 CamtasiaContext * const c = avctx->priv_data; 190 191 av_freep(&c->decomp_buf); 192 193 if (c->pic.data[0]) 194 avctx->release_buffer(avctx, &c->pic); 195 inflateEnd(&(c->zstream)); 196 197 return 0; 198} 199 200AVCodec tscc_decoder = { 201 "camtasia", 202 AVMEDIA_TYPE_VIDEO, 203 CODEC_ID_TSCC, 204 sizeof(CamtasiaContext), 205 decode_init, 206 NULL, 207 decode_end, 208 decode_frame, 209 CODEC_CAP_DR1, 210 .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"), 211}; 212 213