ffmpeg/libavcodec/tscc.c

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/*
* 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 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 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,
};