537 lines
16 KiB
C
537 lines
16 KiB
C
/*
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* RealAudio Lossless decoder
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*
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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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* This is a decoder for Real Audio Lossless format.
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* Dedicated to the mastermind behind it, Ralph Wiggum.
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*/
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#include "avcodec.h"
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#include "get_bits.h"
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#include "golomb.h"
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#include "unary.h"
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#include "libavutil/audioconvert.h"
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#include "ralfdata.h"
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#define FILTER_NONE 0
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#define FILTER_RAW 642
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typedef struct VLCSet {
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VLC filter_params;
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VLC bias;
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VLC coding_mode;
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VLC filter_coeffs[10][11];
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VLC short_codes[15];
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VLC long_codes[125];
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} VLCSet;
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#define RALF_MAX_PKT_SIZE 8192
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typedef struct RALFContext {
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AVFrame frame;
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int version;
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int max_frame_size;
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VLCSet sets[3];
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int32_t channel_data[2][4096];
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int filter_params; ///< combined filter parameters for the current channel data
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int filter_length; ///< length of the filter for the current channel data
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int filter_bits; ///< filter precision for the current channel data
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int32_t filter[64];
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int bias[2]; ///< a constant value added to channel data after filtering
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int num_blocks; ///< number of blocks inside the frame
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int sample_offset;
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int block_size[1 << 12]; ///< size of the blocks
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int block_pts[1 << 12]; ///< block start time (in milliseconds)
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uint8_t pkt[16384];
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int has_pkt;
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} RALFContext;
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#define MAX_ELEMS 644 // no RALF table uses more than that
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static int init_ralf_vlc(VLC *vlc, const uint8_t *data, int elems)
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{
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uint8_t lens[MAX_ELEMS];
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uint16_t codes[MAX_ELEMS];
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int counts[17], prefixes[18];
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int i, cur_len;
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int max_bits = 0;
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int nb = 0;
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for (i = 0; i <= 16; i++)
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counts[i] = 0;
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for (i = 0; i < elems; i++) {
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cur_len = (nb ? *data & 0xF : *data >> 4) + 1;
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counts[cur_len]++;
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max_bits = FFMAX(max_bits, cur_len);
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lens[i] = cur_len;
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data += nb;
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nb ^= 1;
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}
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prefixes[1] = 0;
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for (i = 1; i <= 16; i++)
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prefixes[i + 1] = (prefixes[i] + counts[i]) << 1;
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for (i = 0; i < elems; i++)
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codes[i] = prefixes[lens[i]]++;
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return ff_init_vlc_sparse(vlc, FFMIN(max_bits, 9), elems,
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lens, 1, 1, codes, 2, 2, NULL, 0, 0, 0);
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}
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static av_cold int decode_close(AVCodecContext *avctx)
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{
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RALFContext *ctx = avctx->priv_data;
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int i, j, k;
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for (i = 0; i < 3; i++) {
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ff_free_vlc(&ctx->sets[i].filter_params);
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ff_free_vlc(&ctx->sets[i].bias);
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ff_free_vlc(&ctx->sets[i].coding_mode);
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for (j = 0; j < 10; j++)
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for (k = 0; k < 11; k++)
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ff_free_vlc(&ctx->sets[i].filter_coeffs[j][k]);
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for (j = 0; j < 15; j++)
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ff_free_vlc(&ctx->sets[i].short_codes[j]);
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for (j = 0; j < 125; j++)
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ff_free_vlc(&ctx->sets[i].long_codes[j]);
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}
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return 0;
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}
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static av_cold int decode_init(AVCodecContext *avctx)
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{
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RALFContext *ctx = avctx->priv_data;
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int i, j, k;
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int ret;
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if (avctx->extradata_size < 24 || memcmp(avctx->extradata, "LSD:", 4)) {
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av_log(avctx, AV_LOG_ERROR, "Extradata is not groovy, dude\n");
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return AVERROR_INVALIDDATA;
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}
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ctx->version = AV_RB16(avctx->extradata + 4);
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if (ctx->version != 0x103) {
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av_log_ask_for_sample(avctx, "unknown version %X\n", ctx->version);
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return AVERROR_PATCHWELCOME;
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}
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avctx->channels = AV_RB16(avctx->extradata + 8);
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avctx->sample_rate = AV_RB32(avctx->extradata + 12);
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if (avctx->channels < 1 || avctx->channels > 2
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|| avctx->sample_rate < 8000 || avctx->sample_rate > 96000) {
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av_log(avctx, AV_LOG_ERROR, "Invalid coding parameters %d Hz %d ch\n",
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avctx->sample_rate, avctx->channels);
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return AVERROR_INVALIDDATA;
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}
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avctx->sample_fmt = AV_SAMPLE_FMT_S16;
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avctx->channel_layout = (avctx->channels == 2) ? AV_CH_LAYOUT_STEREO
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: AV_CH_LAYOUT_MONO;
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avcodec_get_frame_defaults(&ctx->frame);
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avctx->coded_frame = &ctx->frame;
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ctx->max_frame_size = AV_RB32(avctx->extradata + 16);
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if (ctx->max_frame_size > (1 << 20) || !ctx->max_frame_size) {
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av_log(avctx, AV_LOG_ERROR, "invalid frame size %d\n",
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ctx->max_frame_size);
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}
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ctx->max_frame_size = FFMAX(ctx->max_frame_size, avctx->sample_rate);
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for (i = 0; i < 3; i++) {
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ret = init_ralf_vlc(&ctx->sets[i].filter_params, filter_param_def[i],
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FILTERPARAM_ELEMENTS);
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if (ret < 0) {
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decode_close(avctx);
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return ret;
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}
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ret = init_ralf_vlc(&ctx->sets[i].bias, bias_def[i], BIAS_ELEMENTS);
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if (ret < 0) {
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decode_close(avctx);
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return ret;
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}
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ret = init_ralf_vlc(&ctx->sets[i].coding_mode, coding_mode_def[i],
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CODING_MODE_ELEMENTS);
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if (ret < 0) {
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decode_close(avctx);
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return ret;
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}
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for (j = 0; j < 10; j++) {
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for (k = 0; k < 11; k++) {
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ret = init_ralf_vlc(&ctx->sets[i].filter_coeffs[j][k],
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filter_coeffs_def[i][j][k],
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FILTER_COEFFS_ELEMENTS);
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if (ret < 0) {
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decode_close(avctx);
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return ret;
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}
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}
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}
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for (j = 0; j < 15; j++) {
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ret = init_ralf_vlc(&ctx->sets[i].short_codes[j],
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short_codes_def[i][j], SHORT_CODES_ELEMENTS);
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if (ret < 0) {
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decode_close(avctx);
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return ret;
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}
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}
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for (j = 0; j < 125; j++) {
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ret = init_ralf_vlc(&ctx->sets[i].long_codes[j],
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long_codes_def[i][j], LONG_CODES_ELEMENTS);
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if (ret < 0) {
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decode_close(avctx);
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return ret;
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}
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}
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}
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return 0;
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}
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static inline int extend_code(GetBitContext *gb, int val, int range, int bits)
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{
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if (val == 0) {
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val = -range - get_ue_golomb(gb);
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} else if (val == range * 2) {
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val = range + get_ue_golomb(gb);
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} else {
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val -= range;
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}
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if (bits)
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val = (val << bits) | get_bits(gb, bits);
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return val;
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}
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static int decode_channel(RALFContext *ctx, GetBitContext *gb, int ch,
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int length, int mode, int bits)
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{
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int i, t;
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int code_params;
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VLCSet *set = ctx->sets + mode;
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VLC *code_vlc; int range, range2, add_bits;
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int *dst = ctx->channel_data[ch];
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ctx->filter_params = get_vlc2(gb, set->filter_params.table, 9, 2);
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ctx->filter_bits = (ctx->filter_params - 2) >> 6;
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ctx->filter_length = ctx->filter_params - (ctx->filter_bits << 6) - 1;
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if (ctx->filter_params == FILTER_RAW) {
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for (i = 0; i < length; i++)
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dst[i] = get_bits(gb, bits);
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ctx->bias[ch] = 0;
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return 0;
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}
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ctx->bias[ch] = get_vlc2(gb, set->bias.table, 9, 2);
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ctx->bias[ch] = extend_code(gb, ctx->bias[ch], 127, 4);
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if (ctx->filter_params == FILTER_NONE) {
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memset(dst, 0, sizeof(*dst) * length);
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return 0;
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}
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if (ctx->filter_params > 1) {
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int cmode = 0, coeff = 0;
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VLC *vlc = set->filter_coeffs[ctx->filter_bits] + 5;
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add_bits = ctx->filter_bits;
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for (i = 0; i < ctx->filter_length; i++) {
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t = get_vlc2(gb, vlc[cmode].table, vlc[cmode].bits, 2);
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t = extend_code(gb, t, 21, add_bits);
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if (!cmode)
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coeff -= 12 << add_bits;
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coeff = t - coeff;
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ctx->filter[i] = coeff;
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cmode = coeff >> add_bits;
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if (cmode < 0) {
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cmode = -1 - av_log2(-cmode);
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if (cmode < -5)
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cmode = -5;
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} else if (cmode > 0) {
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cmode = 1 + av_log2(cmode);
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if (cmode > 5)
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cmode = 5;
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}
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}
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}
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code_params = get_vlc2(gb, set->coding_mode.table, set->coding_mode.bits, 2);
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if (code_params >= 15) {
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add_bits = av_clip((code_params / 5 - 3) / 2, 0, 10);
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if (add_bits > 9 && (code_params % 5) != 2)
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add_bits--;
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range = 10;
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range2 = 21;
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code_vlc = set->long_codes + code_params - 15;
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} else {
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add_bits = 0;
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range = 6;
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range2 = 13;
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code_vlc = set->short_codes + code_params;
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}
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for (i = 0; i < length; i += 2) {
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int code1, code2;
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t = get_vlc2(gb, code_vlc->table, code_vlc->bits, 2);
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code1 = t / range2;
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code2 = t % range2;
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dst[i] = extend_code(gb, code1, range, 0) << add_bits;
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dst[i + 1] = extend_code(gb, code2, range, 0) << add_bits;
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if (add_bits) {
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dst[i] |= get_bits(gb, add_bits);
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dst[i + 1] |= get_bits(gb, add_bits);
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}
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}
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return 0;
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}
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static void apply_lpc(RALFContext *ctx, int ch, int length, int bits)
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{
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int i, j, acc;
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int *audio = ctx->channel_data[ch];
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int bias = 1 << (ctx->filter_bits - 1);
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int max_clip = (1 << bits) - 1, min_clip = -max_clip - 1;
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for (i = 1; i < length; i++) {
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int flen = FFMIN(ctx->filter_length, i);
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acc = 0;
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for (j = 0; j < flen; j++)
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acc += ctx->filter[j] * audio[i - j - 1];
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if (acc < 0) {
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acc = (acc + bias - 1) >> ctx->filter_bits;
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acc = FFMAX(acc, min_clip);
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} else {
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acc = (acc + bias) >> ctx->filter_bits;
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acc = FFMIN(acc, max_clip);
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}
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audio[i] += acc;
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}
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}
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static int decode_block(AVCodecContext *avctx, GetBitContext *gb, int16_t *dst)
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{
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RALFContext *ctx = avctx->priv_data;
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int len, ch, ret;
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int dmode, mode[2], bits[2];
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int *ch0, *ch1;
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int i, t, t2;
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len = 12 - get_unary(gb, 0, 6);
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if (len <= 7) len ^= 1; // codes for length = 6 and 7 are swapped
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len = 1 << len;
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if (ctx->sample_offset + len > ctx->max_frame_size) {
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av_log(avctx, AV_LOG_ERROR,
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"Decoder's stomach is crying, it ate too many samples\n");
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return AVERROR_INVALIDDATA;
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}
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if (avctx->channels > 1)
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dmode = get_bits(gb, 2) + 1;
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else
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dmode = 0;
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mode[0] = (dmode == 4) ? 1 : 0;
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mode[1] = (dmode >= 2) ? 2 : 0;
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bits[0] = 16;
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bits[1] = (mode[1] == 2) ? 17 : 16;
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for (ch = 0; ch < avctx->channels; ch++) {
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if ((ret = decode_channel(ctx, gb, ch, len, mode[ch], bits[ch])) < 0)
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return ret;
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if (ctx->filter_params > 1 && ctx->filter_params != FILTER_RAW) {
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ctx->filter_bits += 3;
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apply_lpc(ctx, ch, len, bits[ch]);
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}
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if (get_bits_left(gb) < 0)
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return AVERROR_INVALIDDATA;
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}
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ch0 = ctx->channel_data[0];
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ch1 = ctx->channel_data[1];
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switch (dmode) {
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case 0:
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for (i = 0; i < len; i++)
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*dst++ = ch0[i] + ctx->bias[0];
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break;
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case 1:
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for (i = 0; i < len; i++) {
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*dst++ = ch0[i] + ctx->bias[0];
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*dst++ = ch1[i] + ctx->bias[1];
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}
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break;
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case 2:
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for (i = 0; i < len; i++) {
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ch0[i] += ctx->bias[0];
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*dst++ = ch0[i];
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*dst++ = ch0[i] - (ch1[i] + ctx->bias[1]);
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}
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break;
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case 3:
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for (i = 0; i < len; i++) {
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t = ch0[i] + ctx->bias[0];
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t2 = ch1[i] + ctx->bias[1];
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*dst++ = t + t2;
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*dst++ = t;
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}
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break;
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case 4:
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for (i = 0; i < len; i++) {
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t = ch1[i] + ctx->bias[1];
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t2 = ((ch0[i] + ctx->bias[0]) << 1) | (t & 1);
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*dst++ = (t2 + t) / 2;
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*dst++ = (t2 - t) / 2;
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}
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break;
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}
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ctx->sample_offset += len;
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return 0;
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}
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static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
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AVPacket *avpkt)
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{
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RALFContext *ctx = avctx->priv_data;
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int16_t *samples;
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int ret;
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GetBitContext gb;
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int table_size, table_bytes, i;
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const uint8_t *src, *block_pointer;
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int src_size;
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int bytes_left;
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if (ctx->has_pkt) {
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ctx->has_pkt = 0;
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table_bytes = (AV_RB16(avpkt->data) + 7) >> 3;
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if (table_bytes + 3 > avpkt->size || avpkt->size > RALF_MAX_PKT_SIZE) {
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av_log(avctx, AV_LOG_ERROR, "Wrong packet's breath smells of wrong data!\n");
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return AVERROR_INVALIDDATA;
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}
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if (memcmp(ctx->pkt, avpkt->data, 2 + table_bytes)) {
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av_log(avctx, AV_LOG_ERROR, "Wrong packet tails are wrong!\n");
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return AVERROR_INVALIDDATA;
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}
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src = ctx->pkt;
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src_size = RALF_MAX_PKT_SIZE + avpkt->size;
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memcpy(ctx->pkt + RALF_MAX_PKT_SIZE, avpkt->data + 2 + table_bytes,
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avpkt->size - 2 - table_bytes);
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} else {
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if (avpkt->size == RALF_MAX_PKT_SIZE) {
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memcpy(ctx->pkt, avpkt->data, avpkt->size);
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ctx->has_pkt = 1;
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*got_frame_ptr = 0;
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return avpkt->size;
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}
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src = avpkt->data;
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src_size = avpkt->size;
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}
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ctx->frame.nb_samples = ctx->max_frame_size;
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if ((ret = avctx->get_buffer(avctx, &ctx->frame)) < 0) {
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av_log(avctx, AV_LOG_ERROR, "Me fail get_buffer()? That's unpossible!\n");
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return ret;
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}
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samples = (int16_t*)ctx->frame.data[0];
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if (src_size < 5) {
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av_log(avctx, AV_LOG_ERROR, "too short packets are too short!\n");
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return AVERROR_INVALIDDATA;
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}
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table_size = AV_RB16(src);
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table_bytes = (table_size + 7) >> 3;
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if (src_size < table_bytes + 3) {
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av_log(avctx, AV_LOG_ERROR, "short packets are short!\n");
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return AVERROR_INVALIDDATA;
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}
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init_get_bits(&gb, src + 2, table_size);
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ctx->num_blocks = 0;
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while (get_bits_left(&gb) > 0) {
|
|
ctx->block_size[ctx->num_blocks] = get_bits(&gb, 15);
|
|
if (get_bits1(&gb)) {
|
|
ctx->block_pts[ctx->num_blocks] = get_bits(&gb, 9);
|
|
} else {
|
|
ctx->block_pts[ctx->num_blocks] = 0;
|
|
}
|
|
ctx->num_blocks++;
|
|
}
|
|
|
|
block_pointer = src + table_bytes + 2;
|
|
bytes_left = src_size - table_bytes - 2;
|
|
ctx->sample_offset = 0;
|
|
for (i = 0; i < ctx->num_blocks; i++) {
|
|
if (bytes_left < ctx->block_size[i]) {
|
|
av_log(avctx, AV_LOG_ERROR, "I'm pedaling backwards\n");
|
|
break;
|
|
}
|
|
init_get_bits(&gb, block_pointer, ctx->block_size[i] * 8);
|
|
if (decode_block(avctx, &gb, samples + ctx->sample_offset
|
|
* avctx->channels) < 0) {
|
|
av_log(avctx, AV_LOG_ERROR, "Sir, I got carsick in your office. Not decoding the rest of packet.\n");
|
|
break;
|
|
}
|
|
block_pointer += ctx->block_size[i];
|
|
bytes_left -= ctx->block_size[i];
|
|
}
|
|
|
|
ctx->frame.nb_samples = ctx->sample_offset;
|
|
*got_frame_ptr = ctx->sample_offset > 0;
|
|
*(AVFrame*)data = ctx->frame;
|
|
|
|
return avpkt->size;
|
|
}
|
|
|
|
static void decode_flush(AVCodecContext *avctx)
|
|
{
|
|
RALFContext *ctx = avctx->priv_data;
|
|
|
|
ctx->has_pkt = 0;
|
|
}
|
|
|
|
|
|
AVCodec ff_ralf_decoder = {
|
|
.name = "ralf",
|
|
.type = AVMEDIA_TYPE_AUDIO,
|
|
.id = AV_CODEC_ID_RALF,
|
|
.priv_data_size = sizeof(RALFContext),
|
|
.init = decode_init,
|
|
.close = decode_close,
|
|
.decode = decode_frame,
|
|
.flush = decode_flush,
|
|
.capabilities = CODEC_CAP_DR1,
|
|
.long_name = NULL_IF_CONFIG_SMALL("RealAudio Lossless"),
|
|
};
|