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-rw-r--r--faad_decoder.cpp243
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diff --git a/faad_decoder.cpp b/faad_decoder.cpp
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+++ b/faad_decoder.cpp
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+/*
+ Copyright (C) 2014 Matthias P. Braendli (http://www.opendigitalradio.org)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+ faad_decoder.cpp
+ Use libfaad to decode the AAC content of the DAB+ subchannel
+
+ Authors:
+ Matthias P. Braendli <matthias@mpb.li>
+*/
+
+#include "faad_decoder.h"
+#include "utils.h"
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <string>
+#include <sstream>
+#include <vector>
+
+using namespace std;
+
+FaadDecoder::FaadDecoder() :
+ m_filename(""),
+ m_ps_flag(0),
+ m_aac_channel_mode(0),
+ m_dac_rate(0),
+ m_sbr_flag(0),
+ m_mpeg_surround_config(0),
+ m_initialised(false)
+{
+ m_decoder = NULL;
+}
+
+FaadDecoder::FaadDecoder(string filename, bool ps_flag, bool aac_channel_mode,
+ bool dac_rate, bool sbr_flag, int mpeg_surround_config) :
+ m_filename(filename),
+ m_ps_flag(ps_flag),
+ m_aac_channel_mode(aac_channel_mode),
+ m_dac_rate(dac_rate),
+ m_sbr_flag(sbr_flag),
+ m_mpeg_surround_config(mpeg_surround_config),
+ m_initialised(false)
+{
+
+ m_decoder = NeAACDecOpen();
+
+ m_fd = fopen(m_filename.c_str(), "w");
+
+#if 0
+ NeAACDecConfigurationPtr config;
+
+ config = NeAACDecGetCurrentConfiguration(m_decoder);
+ if (def_srate)
+ config->defSampleRate = def_srate;
+ config->defObjectType = object_type;
+ config->outputFormat = outputFormat;
+ config->downMatrix = downMatrix;
+ config->useOldADTSFormat = old_format;
+ //config->dontUpSampleImplicitSBR = 1;
+ NeAACDecSetConfiguration(m_decoder, config);
+#endif
+}
+
+size_t FaadDecoder::Decode(vector<vector<uint8_t> > aus)
+{
+ if (!m_decoder) {
+ return 2;
+ }
+
+ /* ADTS header creation taken from SDR-J */
+ adts_fixed_header fh;
+ adts_variable_header vh;
+
+ fh.syncword = 0xfff;
+ fh.id = 0;
+ fh.layer = 0;
+ fh.protection_absent = 1;
+ fh.profile_objecttype = 0; // aac main - 1
+ fh.private_bit = 0; // ignored when decoding
+ fh.original_copy = 0;
+ fh.home = 0;
+ vh.copyright_id_bit = 0;
+ vh.copyright_id_start = 0;
+ vh.adts_buffer_fullness = 1999; // ? according to OpenDab
+ vh.no_raw_data_blocks = 0;
+
+ uint8_t d_header[10];
+ d_header[0] = fh.syncword >> 4;
+ d_header[1] = (fh.syncword & 0xf) << 4;
+ d_header[1] |= fh.id << 3;
+ d_header[1] |= fh.layer << 1;
+ d_header[1] |= fh.protection_absent;
+ d_header[2] = fh.profile_objecttype << 6;
+ // sampling frequency index filled in dynamically
+ d_header[2] |= fh.private_bit << 1;
+ // channel configuration filled in dynamically
+ d_header[3] = fh.original_copy << 5;
+ d_header[3] |= fh.home << 4;
+ d_header[3] |= vh.copyright_id_bit << 3;
+ d_header[3] |= vh.copyright_id_start << 2;
+ // framelength filled in dynamically
+ d_header[4] = 0;
+ d_header[5] = vh.adts_buffer_fullness >> 6;
+ d_header[6] = (vh.adts_buffer_fullness & 0x3f) << 2;
+ d_header[6] |= vh.no_raw_data_blocks;
+
+ if (!m_dac_rate && m_sbr_flag) fh.sampling_freq_idx = 8;
+ // AAC core sampling rate 16 kHz
+ else if (m_dac_rate && m_sbr_flag) fh.sampling_freq_idx = 6;
+ // AAC core sampling rate 24 kHz
+ else if (m_dac_rate && !m_sbr_flag) fh.sampling_freq_idx = 5;
+ // AAC core sampling rate 32 kHz
+ else if (m_dac_rate && !m_sbr_flag) fh.sampling_freq_idx = 3;
+ // AAC core sampling rate 48 kHz
+
+ setBits (&d_header[2], fh.sampling_freq_idx, 2, 4);
+
+ if (m_mpeg_surround_config == 0) {
+ if (m_sbr_flag && !m_aac_channel_mode && m_ps_flag)
+ fh.channel_conf = 2;
+ else
+ fh.channel_conf = 1 << (m_aac_channel_mode ? 1 : 0);
+ }
+ else if (m_mpeg_surround_config == 1) {
+ fh.channel_conf = 6;
+ }
+ else {
+ printf("Unrecognized mpeg surround config (ignored)\n");
+ return 1;
+ }
+
+ setBits (&d_header[2], fh.channel_conf, 7, 3);
+
+
+ for (size_t au_ix = 0; au_ix < aus.size(); au_ix++) {
+
+ vector<uint8_t>& au = aus[au_ix];
+
+ uint8_t helpBuffer[960];
+ memset(helpBuffer, 0, sizeof(helpBuffer));
+
+ // Set length in header
+ vh.aac_frame_length = au.size();
+ setBits(&d_header[3], vh.aac_frame_length, 6, 13);
+
+ memcpy(helpBuffer, d_header, 7 * sizeof(uint8_t));
+ memcpy(&helpBuffer[7],
+ &au[0], vh.aac_frame_length * sizeof (uint8_t));
+
+
+
+ long unsigned samplerate;
+ unsigned char channels;
+ NeAACDecFrameInfo hInfo;
+ int16_t* outBuffer;
+
+ if (!m_initialised) {
+ int len;
+
+ if ((len = NeAACDecInit(m_decoder, helpBuffer,
+ vh.aac_frame_length, &samplerate, &channels)) < 0)
+ {
+ /* If some error initializing occured, skip the file */
+ printf("Error initializing decoder library (%d).\n",
+ len);
+ NeAACDecClose(m_decoder);
+ return 1;
+ }
+
+ m_initialised = true;
+
+ outBuffer = (int16_t *)NeAACDecDecode(
+ m_decoder, &hInfo,
+ helpBuffer + len, vh.aac_frame_length - len );
+ }
+ else {
+ outBuffer = (int16_t *)NeAACDecDecode(
+ m_decoder, &hInfo,
+ helpBuffer, vh.aac_frame_length );
+ }
+
+ int sample_rate = hInfo.samplerate;
+ size_t samples = hInfo.samples;
+
+ printf("bytes consumed %d\n", (int)(hInfo.bytesconsumed));
+ printf("samplerate = %d, samples = %zu, channels = %d,"
+ " error = %d, sbr = %d\n", sample_rate, samples,
+ hInfo.channels, hInfo.error, hInfo.sbr);
+ printf("header = %d\n", hInfo.header_type);
+
+ //channels = hInfo.channels;
+ if (hInfo.error != 0) {
+ printf("FAAD Warning: %s\n",
+ faacDecGetErrorMessage(hInfo.error));
+ return 1;
+ }
+
+ if (channels == 2) {
+ fwrite(outBuffer, 1, samples, m_fd);
+ }
+ else {
+ if (channels == 1) {
+ int16_t *buffer = (int16_t *)alloca (2 * samples);
+ int16_t i;
+ for (i = 0; i < samples; i ++) {
+ buffer [2 * i] = ((int16_t *)outBuffer) [i];
+ buffer [2 * i + 1] = buffer [2 * i];
+ }
+ fwrite(outBuffer, 2, samples, m_fd);
+ }
+ else {
+ printf("Cannot handle these channels\n");
+ }
+ }
+
+ }
+ return 0;
+}
+
+
+FaadDecoder::~FaadDecoder()
+{
+ if (m_decoder) {
+ NeAACDecClose(m_decoder);
+
+ fclose(m_fd);
+ }
+}
+
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