/* * TechSmith Camtasia decoder * Copyright (c) 2004 Konstantin Shishkov * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file tscc.c * TechSmith Camtasia decoder * * Fourcc: TSCC * * Codec is very simple: * it codes picture (picture difference, really) * with algorithm almost identical to Windows RLE8, * only without padding and with greater pixel sizes, * then this coded picture is packed with ZLib * * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested * */ #include <stdio.h> #include <stdlib.h> #include "avcodec.h" #ifdef CONFIG_ZLIB #include <zlib.h> #endif /* * Decoder context */ typedef struct TsccContext { AVCodecContext *avctx; AVFrame pic; // Bits per pixel int bpp; // Decompressed data size unsigned int decomp_size; // Decompression buffer unsigned char* decomp_buf; int height; #ifdef CONFIG_ZLIB z_stream zstream; #endif } CamtasiaContext; /* * * Decode RLE - almost identical to Windows BMP RLE8 * and enhanced to bigger color depths * */ static int decode_rle(CamtasiaContext *c, unsigned int srcsize) { unsigned char *src = c->decomp_buf; unsigned char *output, *output_end; int p1, p2, line=c->height, pos=0, i; uint16_t pix16; uint32_t pix32; output = c->pic.data[0] + (c->height - 1) * c->pic.linesize[0]; output_end = c->pic.data[0] + (c->height) * c->pic.linesize[0]; while(src < c->decomp_buf + srcsize) { p1 = *src++; if(p1 == 0) { //Escape code p2 = *src++; if(p2 == 0) { //End-of-line output = c->pic.data[0] + (--line) * c->pic.linesize[0]; if (line < 0) return -1; pos = 0; continue; } else if(p2 == 1) { //End-of-picture return 0; } else if(p2 == 2) { //Skip p1 = *src++; p2 = *src++; line -= p2; if (line < 0) return -1; pos += p1; output = c->pic.data[0] + line * c->pic.linesize[0] + pos * (c->bpp / 8); continue; } // Copy data if (output + p2 * (c->bpp / 8) > output_end) { src += p2 * (c->bpp / 8); continue; } if ((c->bpp == 8) || (c->bpp == 24)) { for(i = 0; i < p2 * (c->bpp / 8); i++) { *output++ = *src++; } // RLE8 copy is actually padded - and runs are not! if(c->bpp == 8 && (p2 & 1)) { src++; } } else if (c->bpp == 16) { for(i = 0; i < p2; i++) { pix16 = AV_RL16(src); src += 2; *(uint16_t*)output = pix16; output += 2; } } else if (c->bpp == 32) { for(i = 0; i < p2; i++) { pix32 = AV_RL32(src); src += 4; *(uint32_t*)output = pix32; output += 4; } } pos += p2; } else { //Run of pixels int pix[4]; //original pixel switch(c->bpp){ case 8: pix[0] = *src++; break; case 16: pix16 = AV_RL16(src); src += 2; *(uint16_t*)pix = pix16; break; case 24: pix[0] = *src++; pix[1] = *src++; pix[2] = *src++; break; case 32: pix32 = AV_RL32(src); src += 4; *(uint32_t*)pix = pix32; break; } if (output + p1 * (c->bpp / 8) > output_end) continue; for(i = 0; i < p1; i++) { switch(c->bpp){ case 8: *output++ = pix[0]; break; case 16: *(uint16_t*)output = pix16; output += 2; break; case 24: *output++ = pix[0]; *output++ = pix[1]; *output++ = pix[2]; break; case 32: *(uint32_t*)output = pix32; output += 4; break; } } pos += p1; } } av_log(c->avctx, AV_LOG_ERROR, "Camtasia warning: no End-of-picture code\n"); return 1; } /* * * Decode a frame * */ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size) { CamtasiaContext * const c = avctx->priv_data; const unsigned char *encoded = buf; unsigned char *outptr; #ifdef CONFIG_ZLIB int zret; // Zlib return code #endif int len = buf_size; if(c->pic.data[0]) avctx->release_buffer(avctx, &c->pic); c->pic.reference = 1; c->pic.buffer_hints = FF_BUFFER_HINTS_VALID; if(avctx->get_buffer(avctx, &c->pic) < 0){ av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return -1; } outptr = c->pic.data[0]; // Output image pointer #ifdef CONFIG_ZLIB zret = inflateReset(&(c->zstream)); if (zret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret); return -1; } c->zstream.next_in = encoded; c->zstream.avail_in = len; c->zstream.next_out = c->decomp_buf; c->zstream.avail_out = c->decomp_size; zret = inflate(&(c->zstream), Z_FINISH); // Z_DATA_ERROR means empty picture if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) { av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret); return -1; } if(zret != Z_DATA_ERROR) decode_rle(c, c->zstream.avail_out); /* make the palette available on the way out */ if (c->avctx->pix_fmt == PIX_FMT_PAL8) { memcpy(c->pic.data[1], c->avctx->palctrl->palette, AVPALETTE_SIZE); if (c->avctx->palctrl->palette_changed) { c->pic.palette_has_changed = 1; c->avctx->palctrl->palette_changed = 0; } } #else av_log(avctx, AV_LOG_ERROR, "BUG! Zlib support not compiled in frame decoder.\n"); return -1; #endif *data_size = sizeof(AVFrame); *(AVFrame*)data = c->pic; /* always report that the buffer was completely consumed */ return buf_size; } /* * * Init tscc decoder * */ static av_cold int decode_init(AVCodecContext *avctx) { CamtasiaContext * const c = avctx->priv_data; int zret; // Zlib return code c->avctx = avctx; c->pic.data[0] = NULL; c->height = avctx->height; if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) { return 1; } #ifdef CONFIG_ZLIB // Needed if zlib unused or init aborted before inflateInit memset(&(c->zstream), 0, sizeof(z_stream)); #else av_log(avctx, AV_LOG_ERROR, "Zlib support not compiled.\n"); return 1; #endif switch(avctx->bits_per_sample){ case 8: avctx->pix_fmt = PIX_FMT_PAL8; break; case 16: avctx->pix_fmt = PIX_FMT_RGB555; break; case 24: avctx->pix_fmt = PIX_FMT_BGR24; break; case 32: avctx->pix_fmt = PIX_FMT_RGB32; break; default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_sample); return -1; } c->bpp = avctx->bits_per_sample; c->decomp_size = (avctx->width * c->bpp + (avctx->width + 254) / 255 + 2) * avctx->height + 2;//RLE in the 'best' case /* Allocate decompression buffer */ if (c->decomp_size) { if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) { av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); return 1; } } #ifdef CONFIG_ZLIB c->zstream.zalloc = Z_NULL; c->zstream.zfree = Z_NULL; c->zstream.opaque = Z_NULL; zret = inflateInit(&(c->zstream)); if (zret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret); return 1; } #endif return 0; } /* * * Uninit tscc decoder * */ static av_cold int decode_end(AVCodecContext *avctx) { CamtasiaContext * const c = avctx->priv_data; av_freep(&c->decomp_buf); if (c->pic.data[0]) avctx->release_buffer(avctx, &c->pic); #ifdef CONFIG_ZLIB inflateEnd(&(c->zstream)); #endif return 0; } AVCodec tscc_decoder = { "camtasia", CODEC_TYPE_VIDEO, CODEC_ID_TSCC, sizeof(CamtasiaContext), decode_init, NULL, decode_end, decode_frame, CODEC_CAP_DR1, .long_name = "TechSmith Screen Capture Codec", };