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* Feeble Files/ScummVM DXA decoder
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* Copyright (c) 2007 Konstantin Shishkov
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* This file is part of FFmpeg.
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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* @file libavcodec/dxa.c
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#include "libavutil/intreadwrite.h"
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typedef struct DxaDecContext {
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AVCodecContext *avctx;
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static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
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static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
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static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
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uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
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int type, x, y, d, d2;
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int stride = c->pic.linesize[0];
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data = code + ((avctx->width * avctx->height) >> 4);
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mv = data + AV_RB32(src + 0);
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msk = mv + AV_RB32(src + 4);
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for(j = 0; j < avctx->height; j += 4){
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for(i = 0; i < avctx->width; i += 4){
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case 4: // motion compensation
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x = (*mv) >> 4; if(x & 8) x = 8 - x;
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y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
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case 5: // skip in method 12
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for(y = 0; y < 4; y++){
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case 1: // masked change
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case 10: // masked change with only half of pixels changed
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case 11: // cases 10-15 are for method 12 only
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mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
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for(y = 0; y < 4; y++){
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for(x = 0; x < 4; x++){
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tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
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case 2: // fill block
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for(y = 0; y < 4; y++){
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memset(tmp, data[0], 4);
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for(y = 0; y < 4; y++){
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memcpy(tmp, data, 4);
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case 8: // subblocks - method 13 only
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for(k = 0; k < 4; k++){
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d = ((k & 1) << 1) + ((k & 2) * stride);
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d2 = ((k & 1) << 1) + ((k & 2) * stride);
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case 0x80: // motion compensation
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x = (*mv) >> 4; if(x & 8) x = 8 - x;
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y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
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tmp2 += x + y*stride;
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tmp[d + 0 ] = tmp2[0];
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tmp[d + 1 ] = tmp2[1];
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tmp[d + 0 + stride] = tmp2[0 + stride];
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tmp[d + 1 + stride] = tmp2[1 + stride];
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tmp[d + 0 ] = data[0];
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tmp[d + 1 ] = data[0];
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tmp[d + 0 + stride] = data[0];
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tmp[d + 1 + stride] = data[0];
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tmp[d + 0 ] = *data++;
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tmp[d + 1 ] = *data++;
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tmp[d + 0 + stride] = *data++;
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tmp[d + 1 + stride] = *data++;
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case 32: // vector quantization - 2 colors
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for(y = 0; y < 4; y++){
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for(x = 0; x < 4; x++){
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tmp[x] = data[mask & 1];
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case 33: // vector quantization - 3 or 4 colors
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for(y = 0; y < 4; y++){
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for(x = 0; x < 4; x++){
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tmp[x] = data[mask & 3];
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av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
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static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
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DxaDecContext * const c = avctx->priv_data;
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uint8_t *outptr, *srcptr, *tmpptr;
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int orig_buf_size = buf_size;
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/* make the palette available on the way out */
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if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
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for(i = 0; i < 256; i++){
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c->pal[i] = (r << 16) | (g << 8) | b;
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if(avctx->get_buffer(avctx, &c->pic) < 0){
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
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c->pic.palette_has_changed = pc;
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outptr = c->pic.data[0];
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srcptr = c->decomp_buf;
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tmpptr = c->prev.data[0];
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stride = c->pic.linesize[0];
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if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
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if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
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av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
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c->pic.key_frame = 0;
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c->pic.pict_type = FF_P_TYPE;
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memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
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else{ // Should happen only when first frame is 'NULL'
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memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
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c->pic.key_frame = 1;
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c->pic.pict_type = FF_I_TYPE;
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c->pic.key_frame = !(compr & 1);
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c->pic.pict_type = (compr & 1) ? FF_P_TYPE : FF_I_TYPE;
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for(j = 0; j < avctx->height; j++){
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for(i = 0; i < avctx->width; i++)
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outptr[i] = srcptr[i] ^ tmpptr[i];
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memcpy(outptr, srcptr, avctx->width);
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srcptr += avctx->width;
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case 12: // ScummVM coding
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c->pic.key_frame = 0;
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c->pic.pict_type = FF_P_TYPE;
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decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
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av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
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FFSWAP(AVFrame, c->pic, c->prev);
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avctx->release_buffer(avctx, &c->pic);
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*data_size = sizeof(AVFrame);
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*(AVFrame*)data = c->prev;
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/* always report that the buffer was completely consumed */
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return orig_buf_size;
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static av_cold int decode_init(AVCodecContext *avctx)
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DxaDecContext * const c = avctx->priv_data;
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avctx->pix_fmt = PIX_FMT_PAL8;
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if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
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c->dsize = avctx->width * avctx->height * 2;
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if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
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av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
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static av_cold int decode_end(AVCodecContext *avctx)
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DxaDecContext * const c = avctx->priv_data;
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av_freep(&c->decomp_buf);
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avctx->release_buffer(avctx, &c->prev);
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avctx->release_buffer(avctx, &c->pic);
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AVCodec dxa_decoder = {
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sizeof(DxaDecContext),
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.long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
added
removed
libavcodec/dxa.c
