386 lines
12 KiB
C
386 lines
12 KiB
C
/*
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* TechSmith Screen Codec 2 (aka Dora) decoder
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* Copyright (c) 2012 Konstantin Shishkov
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*
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* This file is part of Libav.
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*
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* Libav 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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*
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* Libav 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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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; 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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*/
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/**
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* @file
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* TechSmith Screen Codec 2 decoder
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*/
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#define BITSTREAM_READER_LE
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#include "avcodec.h"
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#include "get_bits.h"
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#include "bytestream.h"
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#include "internal.h"
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#include "tscc2data.h"
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typedef struct TSCC2Context {
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AVCodecContext *avctx;
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AVFrame *pic;
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int mb_width, mb_height;
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uint8_t *slice_quants;
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int quant[2];
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int q[2][3];
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GetBitContext gb;
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VLC dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS];
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int block[16];
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} TSCC2Context;
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static av_cold void free_vlcs(TSCC2Context *c)
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{
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int i;
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ff_free_vlc(&c->dc_vlc);
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for (i = 0; i < NUM_VLC_SETS; i++) {
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ff_free_vlc(c->nc_vlc + i);
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ff_free_vlc(c->ac_vlc + i);
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}
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}
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static av_cold int init_vlcs(TSCC2Context *c)
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{
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int i, ret;
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ret = ff_init_vlc_sparse(&c->dc_vlc, 9, DC_VLC_COUNT,
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tscc2_dc_vlc_bits, 1, 1,
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tscc2_dc_vlc_codes, 2, 2,
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tscc2_dc_vlc_syms, 2, 2, INIT_VLC_LE);
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if (ret)
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return ret;
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for (i = 0; i < NUM_VLC_SETS; i++) {
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ret = ff_init_vlc_sparse(c->nc_vlc + i, 9, 16,
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tscc2_nc_vlc_bits[i], 1, 1,
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tscc2_nc_vlc_codes[i], 2, 2,
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tscc2_nc_vlc_syms, 1, 1, INIT_VLC_LE);
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if (ret) {
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free_vlcs(c);
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return ret;
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}
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ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i],
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tscc2_ac_vlc_bits[i], 1, 1,
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tscc2_ac_vlc_codes[i], 2, 2,
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tscc2_ac_vlc_syms[i], 2, 2, INIT_VLC_LE);
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if (ret) {
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free_vlcs(c);
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return ret;
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}
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}
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return 0;
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}
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#define DEQUANT(val, q) ((q * val + 0x80) >> 8)
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#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
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OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \
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OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \
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OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \
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OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \
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#define COL_OP(a, b) a = b
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#define ROW_OP(a, b) a = ((b) + 0x20) >> 6
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static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
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{
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int i;
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int tblk[4 * 4];
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int t0, t1, t2, t3;
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for (i = 0; i < 4; i++) {
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t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
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t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
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t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
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t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
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DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
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tblk[2 * 4 + i], tblk[3 * 4 + i],
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t0, t1, t2, t3, COL_OP);
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}
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for (i = 0; i < 4; i++) {
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DCT1D(dst[0], dst[1], dst[2], dst[3],
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tblk[i * 4 + 0], tblk[i * 4 + 1],
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tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
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dst += stride;
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}
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}
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static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
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uint8_t *dst, int stride, int plane)
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{
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GetBitContext *gb = &c->gb;
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int prev_dc, dc, nc, ac, bpos, val;
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int i, j, k, l;
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if (get_bits1(gb)) {
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if (get_bits1(gb)) {
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val = get_bits(gb, 8);
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for (i = 0; i < 8; i++, dst += stride)
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memset(dst, val, 16);
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} else {
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if (get_bits_left(gb) < 16 * 8 * 8)
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return AVERROR_INVALIDDATA;
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for (i = 0; i < 8; i++) {
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for (j = 0; j < 16; j++)
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dst[j] = get_bits(gb, 8);
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dst += stride;
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}
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}
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return 0;
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}
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prev_dc = 0;
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for (j = 0; j < 2; j++) {
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for (k = 0; k < 4; k++) {
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if (!(j | k)) {
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dc = get_bits(gb, 8);
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} else {
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dc = get_vlc2(gb, c->dc_vlc.table, 9, 2);
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if (dc == -1)
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return AVERROR_INVALIDDATA;
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if (dc == 0x100)
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dc = get_bits(gb, 8);
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}
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dc = (dc + prev_dc) & 0xFF;
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prev_dc = dc;
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c->block[0] = dc;
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nc = get_vlc2(gb, c->nc_vlc[vlc_set].table, 9, 1);
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if (nc == -1)
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return AVERROR_INVALIDDATA;
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bpos = 1;
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memset(c->block + 1, 0, 15 * sizeof(*c->block));
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for (l = 0; l < nc; l++) {
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ac = get_vlc2(gb, c->ac_vlc[vlc_set].table, 9, 2);
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if (ac == -1)
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return AVERROR_INVALIDDATA;
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if (ac == 0x1000)
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ac = get_bits(gb, 12);
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bpos += ac & 0xF;
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if (bpos >= 16)
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return AVERROR_INVALIDDATA;
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val = sign_extend(ac >> 4, 8);
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c->block[tscc2_zigzag[bpos++]] = val;
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}
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tscc2_idct4_put(c->block, q, dst + k * 4, stride);
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}
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dst += 4 * stride;
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}
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return 0;
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}
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static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
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const uint8_t *buf, int buf_size)
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{
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int i, mb_x, q, ret;
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int off;
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init_get_bits(&c->gb, buf, buf_size * 8);
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for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
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q = c->slice_quants[mb_x + c->mb_width * mb_y];
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if (q == 0 || q == 3) // skip block
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continue;
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for (i = 0; i < 3; i++) {
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off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
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ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
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c->pic->data[i] + off, c->pic->linesize[i], i);
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if (ret)
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return ret;
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}
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}
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return 0;
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}
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static int tscc2_decode_frame(AVCodecContext *avctx, void *data,
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int *got_frame, AVPacket *avpkt)
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{
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const uint8_t *buf = avpkt->data;
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int buf_size = avpkt->size;
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TSCC2Context *c = avctx->priv_data;
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GetByteContext gb;
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uint32_t frame_type, size;
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int i, val, len, pos = 0;
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int num_mb = c->mb_width * c->mb_height;
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int ret;
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bytestream2_init(&gb, buf, buf_size);
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frame_type = bytestream2_get_byte(&gb);
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if (frame_type > 1) {
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av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %d\n", frame_type);
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return AVERROR_INVALIDDATA;
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}
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if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) {
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av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
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return ret;
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}
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if (frame_type == 0) {
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*got_frame = 1;
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if ((ret = av_frame_ref(data, c->pic)) < 0)
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return ret;
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return buf_size;
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}
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if (bytestream2_get_bytes_left(&gb) < 4) {
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av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
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return AVERROR_INVALIDDATA;
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}
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c->quant[0] = bytestream2_get_byte(&gb);
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c->quant[1] = bytestream2_get_byte(&gb);
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if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
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c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
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av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
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c->quant[0], c->quant[1]);
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return AVERROR_INVALIDDATA;
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}
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for (i = 0; i < 3; i++) {
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c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
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c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
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}
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bytestream2_skip(&gb, 1);
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size = bytestream2_get_le32(&gb);
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if (size > bytestream2_get_bytes_left(&gb)) {
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av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
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return AVERROR_INVALIDDATA;
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}
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for (i = 0; i < size; i++) {
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val = bytestream2_get_byte(&gb);
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len = val & 0x3F;
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val >>= 6;
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if (pos + len > num_mb) {
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av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
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return AVERROR_INVALIDDATA;
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}
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memset(c->slice_quants + pos, val, len);
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pos += len;
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}
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if (pos < num_mb) {
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av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
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pos, num_mb);
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return AVERROR_INVALIDDATA;
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}
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for (i = 0; i < c->mb_height; i++) {
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size = bytestream2_peek_byte(&gb);
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if (size & 1) {
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size = bytestream2_get_byte(&gb) - 1;
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} else {
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size = bytestream2_get_le32(&gb) >> 1;
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}
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if (!size) {
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int skip_row = 1, j, off = i * c->mb_width;
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for (j = 0; j < c->mb_width; j++) {
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if (c->slice_quants[off + j] == 1 ||
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c->slice_quants[off + j] == 2) {
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skip_row = 0;
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break;
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}
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}
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if (!skip_row) {
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av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
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return AVERROR_INVALIDDATA;
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}
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}
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if (bytestream2_get_bytes_left(&gb) < size) {
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av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%d/%d)\n",
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size, bytestream2_get_bytes_left(&gb));
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return AVERROR_INVALIDDATA;
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}
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ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
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if (ret) {
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av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
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return ret;
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}
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bytestream2_skip(&gb, size);
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}
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*got_frame = 1;
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if ((ret = av_frame_ref(data, c->pic)) < 0)
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return ret;
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/* always report that the buffer was completely consumed */
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return buf_size;
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}
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static av_cold int tscc2_decode_end(AVCodecContext *avctx)
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{
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TSCC2Context * const c = avctx->priv_data;
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av_frame_free(&c->pic);
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av_freep(&c->slice_quants);
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free_vlcs(c);
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return 0;
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}
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static av_cold int tscc2_decode_init(AVCodecContext *avctx)
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{
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TSCC2Context * const c = avctx->priv_data;
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int ret;
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c->avctx = avctx;
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avctx->pix_fmt = AV_PIX_FMT_YUV444P;
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if ((ret = init_vlcs(c)) < 0) {
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av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
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return ret;
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}
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c->mb_width = FFALIGN(avctx->width, 16) >> 4;
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c->mb_height = FFALIGN(avctx->height, 8) >> 3;
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c->slice_quants = av_malloc(c->mb_width * c->mb_height);
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if (!c->slice_quants) {
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av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
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free_vlcs(c);
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return AVERROR(ENOMEM);
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}
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c->pic = av_frame_alloc();
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if (!c->pic) {
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tscc2_decode_end(avctx);
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return AVERROR(ENOMEM);
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}
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return 0;
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}
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AVCodec ff_tscc2_decoder = {
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.name = "tscc2",
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.long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
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.type = AVMEDIA_TYPE_VIDEO,
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.id = AV_CODEC_ID_TSCC2,
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.priv_data_size = sizeof(TSCC2Context),
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.init = tscc2_decode_init,
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.close = tscc2_decode_end,
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.decode = tscc2_decode_frame,
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.capabilities = CODEC_CAP_DR1,
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};
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