1/* 2 * TechSmith Camtasia decoder 3 * Copyright (c) 2004 Konstantin Shishkov 4 * 5 * This file is part of Libav. 6 * 7 * Libav 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 * Libav 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 Libav; 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 GetByteContext gb; 62 int height; 63 z_stream zstream; 64 65 uint32_t pal[256]; 66} CamtasiaContext; 67 68/* 69 * 70 * Decode a frame 71 * 72 */ 73static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) 74{ 75 const uint8_t *buf = avpkt->data; 76 int buf_size = avpkt->size; 77 CamtasiaContext * const c = avctx->priv_data; 78 const unsigned char *encoded = buf; 79 int zret; // Zlib return code 80 int len = buf_size; 81 82 if(c->pic.data[0]) 83 avctx->release_buffer(avctx, &c->pic); 84 85 c->pic.reference = 1; 86 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID; 87 if(avctx->get_buffer(avctx, &c->pic) < 0){ 88 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 89 return -1; 90 } 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 bytestream2_init(&c->gb, c->decomp_buf, 111 c->decomp_size - c->zstream.avail_out); 112 ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, &c->gb); 113 } 114 115 /* make the palette available on the way out */ 116 if (c->avctx->pix_fmt == PIX_FMT_PAL8) { 117 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); 118 119 if (pal) { 120 c->pic.palette_has_changed = 1; 121 memcpy(c->pal, pal, AVPALETTE_SIZE); 122 } 123 memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE); 124 } 125 126 *data_size = sizeof(AVFrame); 127 *(AVFrame*)data = c->pic; 128 129 /* always report that the buffer was completely consumed */ 130 return buf_size; 131} 132 133 134 135/* 136 * 137 * Init tscc decoder 138 * 139 */ 140static av_cold int decode_init(AVCodecContext *avctx) 141{ 142 CamtasiaContext * const c = avctx->priv_data; 143 int zret; // Zlib return code 144 145 c->avctx = avctx; 146 147 c->height = avctx->height; 148 149 // Needed if zlib unused or init aborted before inflateInit 150 memset(&c->zstream, 0, sizeof(z_stream)); 151 switch(avctx->bits_per_coded_sample){ 152 case 8: avctx->pix_fmt = PIX_FMT_PAL8; break; 153 case 16: avctx->pix_fmt = PIX_FMT_RGB555; break; 154 case 24: 155 avctx->pix_fmt = PIX_FMT_BGR24; 156 break; 157 case 32: avctx->pix_fmt = PIX_FMT_RGB32; break; 158 default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample); 159 return -1; 160 } 161 c->bpp = avctx->bits_per_coded_sample; 162 // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too 163 c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2; 164 165 /* Allocate decompression buffer */ 166 if (c->decomp_size) { 167 if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) { 168 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); 169 return 1; 170 } 171 } 172 173 c->zstream.zalloc = Z_NULL; 174 c->zstream.zfree = Z_NULL; 175 c->zstream.opaque = Z_NULL; 176 zret = inflateInit(&c->zstream); 177 if (zret != Z_OK) { 178 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret); 179 return 1; 180 } 181 182 return 0; 183} 184 185 186 187/* 188 * 189 * Uninit tscc decoder 190 * 191 */ 192static av_cold int decode_end(AVCodecContext *avctx) 193{ 194 CamtasiaContext * const c = avctx->priv_data; 195 196 av_freep(&c->decomp_buf); 197 198 if (c->pic.data[0]) 199 avctx->release_buffer(avctx, &c->pic); 200 inflateEnd(&c->zstream); 201 202 return 0; 203} 204 205AVCodec ff_tscc_decoder = { 206 .name = "camtasia", 207 .type = AVMEDIA_TYPE_VIDEO, 208 .id = CODEC_ID_TSCC, 209 .priv_data_size = sizeof(CamtasiaContext), 210 .init = decode_init, 211 .close = decode_end, 212 .decode = decode_frame, 213 .capabilities = CODEC_CAP_DR1, 214 .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"), 215}; 216 217