path: root/src/dabplus-enc.cpp

/* ------------------------------------------------------------------
 * Copyright (C) 2011 Martin Storsjo
 * Copyright (C) 2013,2014,2015 Matthias P. Braendli
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 * -------------------------------------------------------------------
 */

#include "config.h"
#include "AlsaInput.h"
#include "FileInput.h"
#include "JackInput.h"
#include "VLCInput.h"
#include "SampleQueue.h"
#include "zmq.hpp"

extern "C" {
#include "encryption.h"
#include "utils.h"
#include "wavreader.h"
}

#include <vector>
#include <string>
#include <getopt.h>
#include <cstdio>
#include <stdint.h>
#include <time.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>

#include "libAACenc/include/aacenc_lib.h"

extern "C" {
#include <fec.h>
}

using namespace std;

void usage(const char* name) {
    fprintf(stderr,
    "dabplus-enc %s is a HE-AACv2 encoder for DAB+\n"
    "based on fdk-aac-dabplus that can read from"
    "JACK, ALSA or a file source\n"
    "and encode to a ZeroMQ output for ODR-DabMux.\n"
    "(Experimental!)It can also use libvlc as an input.\n"
    "\n"
    "The -D option enables experimental sound card clock drift compensation.\n"
    "A consumer sound card has a clock that is always a bit imprecise, and\n"
    "would drift off after some time. ODR-DabMux cannot handle such drift\n"
    "because it would have to throw away or insert a full DAB+ superframe,\n"
    "which would create audible artifacts. This drift compensation can\n"
    "make sure that the encoding rate is correct by inserting or deleting\n"
    "audio samples. It can be used for both ALSA and VLC inputs.\n"
    "\n"
    "When this option is enabled, you will see U and O printed in the\n"
    "console. These correspond to audio underruns and overruns caused\n"
    "by sound card clock drift. When sparse, they should not create audible\n"
    "artifacts.\n"
    "\n"
    "This encoder includes PAD (DLS and MOT Slideshow) support by\n"
    "http://rd.csp.it to be used with mot-encoder\n"
    "\nUsage:\n"
    "%s (-i file|-d alsa_device) [OPTION...]\n",
#if defined(GITVERSION)
    GITVERSION
#else
    PACKAGE_VERSION
#endif
    , name);
    fprintf(stderr,
    "   For the alsa input:\n"
    "     -d, --device=alsa_device             Set ALSA input device (default: \"default\").\n"
    "   For the file input:\n"
    "     -i, --input=FILENAME                 Input filename (default: stdin).\n"
    "     -f, --format={ wav, raw }            Set input file format (default: wav).\n"
    "         --fifo-silence                   Input file is fifo and encoder generates silence when fifo is empty. Ignore EOF.\n"
    "   For the JACK input:\n"
#if HAVE_JACK
    "     -j, --jack=name                      Enable JACK input, and define our name\n"
#else
    "     The JACK input was disabled at compile-time\n"
#endif
    "   For the VLC input:\n"
#if HAVE_VLC
    "     -v, --vlc-uri=uri                    Enable VLC input and use the URI given as source\n"
    "     -C, --vlc-cache=ms                   Enable VLC network cache\n"
    "     -g, --vlc-gain=db                    Enable VLC gain control, default 0\n"
    "     -V                                   Increase the VLC verbosity by one (can be given \n"
    "                                          multiple times)\n"
    "     -w, --write-icy-text=filename        Write the ICY Text into the file, so that mot-encoder can read it.\n"
#else
    "     The VLC input was disabled at compile-time\n"
#endif
    "   Drift compensation\n"
    "     -D, --drift-comp                     Enable ALSA/VLC sound card drift compensation.\n"
    "   Encoder parameters:\n"
    "     -b, --bitrate={ 8, 16, ..., 192 }    Output bitrate in kbps. Must be a multiple of 8.\n"
    "     -A, --no-afterburner                 Disable AAC encoder quality increaser.\n"
    "     -c, --channels={ 1, 2 }              Nb of input channels (default: 2).\n"
    "     -r, --rate={ 32000, 48000 }          Input sample rate (default: 48000).\n"
    "         --aaclc                          Force the usage of AAC-LC (no SBR, no PS)\n"
    "         --sbr                            Force the usage of SBR\n"
    "         --ps                             Force the usage of PS\n"
    "   Output and pad parameters:\n"
    "     -o, --output=URI                     Output ZMQ uri. (e.g. 'tcp://localhost:9000')\n"
    "                                     -or- Output file uri. (e.g. 'file.dabp')\n"
    "                                     -or- a single dash '-' to denote stdout\n"
    "                                          If more than one ZMQ output is given, the socket\n"
    "                                          will be connected to all listed endpoints.\n"
    "     -k, --secret-key=FILE                Enable ZMQ encryption with the given secret key.\n"
    "     -p, --pad=BYTES                      Set PAD size in bytes.\n"
    "     -P, --pad-fifo=FILENAME              Set PAD data input fifo name"
    "                                          (default: /tmp/pad.fifo).\n"
    "     -l, --level                          Show peak audio level indication.\n"
    "     -s, --silence=TIMEOUT                Abort encoding after TIMEOUT seconds of silence.\n"
    "\n"
    "Only the tcp:// zeromq transport has been tested until now,\n"
    " but epgm:// and pgm:// are also accepted\n"
    );

}

int prepare_aac_encoder(
        HANDLE_AACENCODER *encoder,
        int subchannel_index,
        int channels,
        int sample_rate,
        int afterburner,
        int *aot)
{
    CHANNEL_MODE mode;
    switch (channels) {
        case 1: mode = MODE_1; break;
        case 2: mode = MODE_2; break;
        default:
                fprintf(stderr, "Unsupported channels number %d\n", channels);
                return 1;
    }


    if (aacEncOpen(encoder, 0x01|0x02|0x04, channels) != AACENC_OK) {
        fprintf(stderr, "Unable to open encoder\n");
        return 1;
    }

    if (*aot == AOT_NONE) {

        if(channels == 2 && subchannel_index <= 6) {
            *aot = AOT_DABPLUS_PS;
        }
        else if((channels == 1 && subchannel_index <= 8) || subchannel_index <= 10) {
            *aot = AOT_DABPLUS_SBR;
        }
        else {
            *aot = AOT_DABPLUS_AAC_LC;
        }
    }

    fprintf(stderr, "Using %d subchannels. AAC type: %s%s%s. channels=%d, sample_rate=%d\n",
            subchannel_index,
            *aot == AOT_DABPLUS_PS ? "HE-AAC v2" : "",
            *aot == AOT_DABPLUS_SBR ? "HE-AAC" : "",
            *aot == AOT_DABPLUS_AAC_LC ? "AAC-LC" : "",
            channels, sample_rate);

    if (aacEncoder_SetParam(*encoder, AACENC_AOT, *aot) != AACENC_OK) {
        fprintf(stderr, "Unable to set the AOT\n");
        return 1;
    }
    if (aacEncoder_SetParam(*encoder, AACENC_SAMPLERATE, sample_rate) != AACENC_OK) {
        fprintf(stderr, "Unable to set the sample rate\n");
        return 1;
    }
    if (aacEncoder_SetParam(*encoder, AACENC_CHANNELMODE, mode) != AACENC_OK) {
        fprintf(stderr, "Unable to set the channel mode\n");
        return 1;
    }
    if (aacEncoder_SetParam(*encoder, AACENC_CHANNELORDER, 1) != AACENC_OK) {
        fprintf(stderr, "Unable to set the wav channel order\n");
        return 1;
    }
    if (aacEncoder_SetParam(*encoder, AACENC_GRANULE_LENGTH, 960) != AACENC_OK) {
        fprintf(stderr, "Unable to set the granule length\n");
        return 1;
    }
    if (aacEncoder_SetParam(*encoder, AACENC_TRANSMUX, TT_DABPLUS) != AACENC_OK) {
        fprintf(stderr, "Unable to set the RAW transmux\n");
        return 1;
    }

    /*if (aacEncoder_SetParam(*encoder, AACENC_BITRATEMODE, AACENC_BR_MODE_SFR)
     * != AACENC_OK) {
        fprintf(stderr, "Unable to set the bitrate mode\n");
        return 1;
    }*/


    fprintf(stderr, "AAC bitrate set to: %d\n", subchannel_index*8000);
    if (aacEncoder_SetParam(*encoder, AACENC_BITRATE, subchannel_index*8000) != AACENC_OK) {
        fprintf(stderr, "Unable to set the bitrate\n");
        return 1;
    }
    if (aacEncoder_SetParam(*encoder, AACENC_AFTERBURNER, afterburner) != AACENC_OK) {
        fprintf(stderr, "Unable to set the afterburner mode\n");
        return 1;
    }
    if (!afterburner) {
        fprintf(stderr, "Warning: Afterburned disabled!\n");
    }
    if (aacEncEncode(*encoder, NULL, NULL, NULL, NULL) != AACENC_OK) {
        fprintf(stderr, "Unable to initialize the encoder\n");
        return 1;
    }
    return 0;
}

#define no_argument 0
#define required_argument 1
#define optional_argument 2

#define STATUS_PAD_INSERTED 0x1
#define STATUS_OVERRUN 0x2
#define STATUS_UNDERRUN 0x4

int main(int argc, char *argv[])
{
    int subchannel_index = 8; //64kbps subchannel
    int ch=0;

    // For the ALSA input
    const char *alsa_device = NULL;

    // For the file input
    const char *infile = NULL;
    int raw_input = 0;

    // For the VLC input
    std::string vlc_uri = "";
    std::string vlc_icytext_file = "";
    std::string vlc_gain = "";
    std::string vlc_cache = "";
    unsigned verbosity = 0;

    // For the file output
    FILE *out_fh = NULL;

    const char *jack_name = NULL;

    std::vector<std::string> output_uris;

    int sample_rate=48000, channels=2;
    void *rs_handler = NULL;
    bool afterburner = true;
    bool inFifoSilence = false;
    bool drift_compensation = false;
    AACENC_InfoStruct info = { 0 };
    int aot = AOT_NONE;

    /* Keep track of peaks */
    int peak_left  = 0;
    int peak_right = 0;

    /* On silence, die after the silence_timeout expires */
    bool die_on_silence = false;
    int silence_timeout = 0;
    int measured_silence_ms = 0;

    /* For MOT Slideshow and DLS insertion */
    const char* pad_fifo = "/tmp/pad.fifo";
    int pad_fd;
    int padlen = 0;

    /* Encoder status, see the above STATUS macros */
    int status = 0;

    /* Whether to show the 'sox'-like measurement */
    int show_level = 0;

    /* Data for ZMQ CURVE authentication */
    char* keyfile = NULL;
    char secretkey[CURVE_KEYLEN+1];

    const struct option longopts[] = {
        {"bitrate",        required_argument,  0, 'b'},
        {"channels",       required_argument,  0, 'c'},
        {"device",         required_argument,  0, 'd'},
        {"format",         required_argument,  0, 'f'},
        {"input",          required_argument,  0, 'i'},
        {"jack",           required_argument,  0, 'j'},
        {"output",         required_argument,  0, 'o'},
        {"pad",            required_argument,  0, 'p'},
        {"pad-fifo",       required_argument,  0, 'P'},
        {"rate",           required_argument,  0, 'r'},
        {"secret-key",     required_argument,  0, 'k'},
        {"silence",        required_argument,  0, 's'},
        {"vlc-cache",      required_argument,  0, 'C'},
        {"vlc-gain",       required_argument,  0, 'g'},
        {"vlc-uri",        required_argument,  0, 'v'},
        {"write-icy-text", required_argument,  0, 'w'},
        {"aaclc",          no_argument,        0,  0 },
        {"afterburner",    no_argument,        0, 'a'},
        {"drift-comp",     no_argument,        0, 'D'},
        {"fifo-silence",   no_argument,        0,  3 },
        {"help",           no_argument,        0, 'h'},
        {"level",          no_argument,        0, 'l'},
        {"no-afterburner", no_argument,        0, 'A'},
        {"ps",             no_argument,        0,  2 },
        {"sbr",            no_argument,        0,  1 },
        {"verbosity",      no_argument,        0, 'V'},
        {0, 0, 0, 0},
    };

    fprintf(stderr,
            "Welcome to %s %s, compiled at %s, %s",
            PACKAGE_NAME,
#if defined(GITVERSION)
            GITVERSION,
#else
            PACKAGE_VERSION,
#endif
            __DATE__, __TIME__);
    fprintf(stderr, "\n");
    fprintf(stderr, "  http://opendigitalradio.org\n\n");


    if (argc < 2) {
        usage(argv[0]);
        return 1;
    }

    int index;
    while(ch != -1) {
        ch = getopt_long(argc, argv, "aAhDlVb:c:f:i:j:k:o:r:d:p:P:s:v:w:g:C:", longopts, &index);
        switch (ch) {
        case 0: // AAC-LC
            aot = AOT_DABPLUS_AAC_LC;
            break;
        case 1: // SBR
            aot = AOT_DABPLUS_SBR;
            break;
        case 2: // PS
            aot = AOT_DABPLUS_PS;
            break;
        case 3: // FIFO SILENCE
            inFifoSilence = true;
            break;
        case 'a':
            fprintf(stderr, "Warning, -a option does not exist anymore!\n");
            break;
        case 'A':
            afterburner = false;
            break;
        case 'b':
            subchannel_index = atoi(optarg) / 8;
            break;
        case 'c':
            channels = atoi(optarg);
            break;
        case 'd':
            alsa_device = optarg;
            break;
        case 'D':
            drift_compensation = true;
            break;
        case 'f':
            if(strcmp(optarg, "raw")==0) {
                raw_input = 1;
            } else if(strcmp(optarg, "wav")!=0)
                usage(argv[0]);
            break;
        case 'i':
            infile = optarg;
            break;
        case 'j':
#if HAVE_JACK
            jack_name = optarg;
#else
            fprintf(stderr, "JACK disabled at compile time!\n");
            return 1;
#endif
            break;
        case 'k':
            keyfile = optarg;
            break;
        case 'l':
            show_level = 1;
            break;
        case 'o':
            output_uris.push_back(optarg);
            break;
        case 'p':
            padlen = atoi(optarg);
            break;
        case 'P':
            pad_fifo = optarg;
            break;
        case 'r':
            sample_rate = atoi(optarg);
            break;
        case 's':
            silence_timeout = atoi(optarg);
            if (silence_timeout > 0 && silence_timeout < 3600*24*30) {
                die_on_silence = true;
            }
            else {
                fprintf(stderr, "Invalid silence timeout (%d) given!\n", silence_timeout);
                return 1;
            }

            break;
#ifdef HAVE_VLC
        case 'v':
            vlc_uri = optarg;
            break;
        case 'w':
            vlc_icytext_file = optarg;
            break;
        case 'g':
            vlc_gain = optarg;
            break;
        case 'C':
            vlc_cache = optarg;
            break;
#else
        case 'v':
        case 'w':
            fprintf(stderr, "VLC input not enabled at compile time!\n");
            return 1;
#endif
        case 'V':
            verbosity++;
            break;
        case '?':
        case 'h':
            usage(argv[0]);
            return 1;
        }
    }

    int num_inputs = 0;
    if (alsa_device) num_inputs++;
    if (infile) num_inputs++;
    if (jack_name) num_inputs++;
    if (vlc_uri != "") num_inputs++;

    if (num_inputs > 1) {
        fprintf(stderr, "You must define only one possible input, not several!\n");
        return 1;
    }

    if (subchannel_index < 1 || subchannel_index > 24) {
        fprintf(stderr, "Bad subchannel index: %d, must be between 1 and 24. Try other bitrate.\n",
                subchannel_index);
        return 1;
    }

    if ( ! (sample_rate == 32000 || sample_rate == 48000)) {
        fprintf(stderr, "Invalid sample rate. Possible values are: 32000, 48000.\n");
        return 1;
    }

    if (padlen < 0) {
        fprintf(stderr, "Invalid PAD length specified\n");
        return 1;
    }

    zmq::context_t zmq_ctx;
    zmq::socket_t zmq_sock(zmq_ctx, ZMQ_PUB);

    if (not output_uris.empty()) {
        for (auto uri : output_uris) {
            if (uri == "-") {
                if (out_fh != NULL) {
                    fprintf(stderr, "You can't write to more than one file!\n");
                    return 1;
                }
                out_fh = stdout;
            }
            else if ((uri.compare(0, 6, "tcp://") == 0) ||
                    (uri.compare(0, 6, "pgm://") == 0) ||
                    (uri.compare(0, 7, "epgm://") == 0)) {
                if (keyfile) {
                    fprintf(stderr, "Enabling encryption\n");

                    int rc = readkey(keyfile, secretkey);
                    if (rc) {
                        fprintf(stderr, "Error reading secret key\n");
                        return 2;
                    }

                    const int yes = 1;
                    zmq_sock.setsockopt(ZMQ_CURVE_SERVER,
                            &yes, sizeof(yes));

                    zmq_sock.setsockopt(ZMQ_CURVE_SECRETKEY,
                            secretkey, CURVE_KEYLEN);
                }
                zmq_sock.connect(uri.c_str());
            }
            else { // We assume it's a file name
                if (out_fh != NULL) {
                    fprintf(stderr, "You can't write to more than one file!\n");
                    return 1;
                }

                out_fh = fopen(uri.c_str(), "wb");

                if (!out_fh) {
                    fprintf(stderr, "Can't open output file!\n");
                    return 1;
                }
            }
        }
    }
    else {
        fprintf(stderr, "No output URI defined\n");
        return 1;
    }

    if (padlen != 0) {
        int flags;
        if (mkfifo(pad_fifo, S_IWUSR | S_IRUSR | S_IRGRP | S_IROTH) != 0) {
            if (errno != EEXIST) {
                fprintf(stderr, "Can't create pad file: %d!\n", errno);
                return 1;
            }
        }
        pad_fd = open(pad_fifo, O_RDONLY | O_NONBLOCK);
        if (pad_fd == -1) {
            fprintf(stderr, "Can't open pad file!\n");
            return 1;
        }
        flags = fcntl(pad_fd, F_GETFL, 0);
        if (fcntl(pad_fd, F_SETFL, flags | O_NONBLOCK)) {
            fprintf(stderr, "Can't set non-blocking mode in pad file!\n");
            return 1;
        }
    }


    HANDLE_AACENCODER encoder;

    if (prepare_aac_encoder(&encoder, subchannel_index, channels,
                sample_rate, afterburner, &aot) != 0) {
        fprintf(stderr, "Encoder preparation failed\n");
        return 1;
    }

    /* We assume that we need to call the encoder
     * enc_calls_per_output before it gives us one encoded audio
     * frame. This information is used when the alsa drift compensation
     * is active
     */
    const int enc_calls_per_output =
        (aot == AOT_DABPLUS_AAC_LC) ? sample_rate / 8000 : sample_rate / 16000;


    if (aacEncInfo(encoder, &info) != AACENC_OK) {
        fprintf(stderr, "Unable to get the encoder info\n");
        return 1;
    }

    // Each DAB+ frame will need input_size audio bytes
    const int input_size = channels * BYTES_PER_SAMPLE * info.frameLength;
    fprintf(stderr, "DAB+ Encoding: framelen=%d (%dB)\n",
            info.frameLength,
            input_size);

    uint8_t input_buf[input_size];

    int max_size = 4*input_size + NUM_SAMPLES_PER_CALL;

    SampleQueue<uint8_t> queue(BYTES_PER_SAMPLE, channels, max_size);

    /* symsize=8, gfpoly=0x11d, fcr=0, prim=1, nroots=10, pad=135 */
    rs_handler = init_rs_char(8, 0x11d, 0, 1, 10, 135);
    if (rs_handler == NULL) {
        perror("init_rs_char failed");
        return 1;
    }

    /* No input defined ? default to alsa "default" */
    if (!alsa_device) {
        alsa_device = "default";
    }

    // We'll use one of the tree possible inputs
    AlsaInputThreaded alsa_in_threaded(alsa_device, channels, sample_rate, queue);
    AlsaInputDirect   alsa_in_direct(alsa_device, channels, sample_rate);
    FileInput         file_in(infile, raw_input, sample_rate);
#if HAVE_JACK
    JackInput         jack_in(jack_name, channels, sample_rate, queue);
#endif
#if HAVE_VLC
    VLCInputDirect    vlc_in_direct(vlc_uri, sample_rate, channels, verbosity, vlc_gain, vlc_cache);
    VLCInputThreaded  vlc_in_threaded(vlc_uri, sample_rate, channels, verbosity, vlc_gain, vlc_cache, queue);
#endif

    if (infile) {
        if (file_in.prepare() != 0) {
            fprintf(stderr, "File input preparation failed\n");
            return 1;
        }
    }
#if HAVE_JACK
    else if (jack_name) {
        if (jack_in.prepare() != 0) {
            fprintf(stderr, "JACK preparation failed\n");
            return 1;
        }
    }
#endif
#if HAVE_VLC
    else if (vlc_uri != "") {
        if (drift_compensation) {
            if (vlc_in_threaded.prepare() != 0) {
                fprintf(stderr, "VLC with drift compensation: preparation failed\n");
                return 1;
            }

            fprintf(stderr, "Start VLC thread\n");
            vlc_in_threaded.start();
        }
        else {
            if (vlc_in_direct.prepare() != 0) {
                fprintf(stderr, "VLC preparation failed\n");
                return 1;
            }
        }
    }
#endif
    else if (drift_compensation) {
        if (alsa_in_threaded.prepare() != 0) {
            fprintf(stderr, "Alsa with drift compensation: preparation failed\n");
            return 1;
        }

        fprintf(stderr, "Start ALSA capture thread\n");
        alsa_in_threaded.start();
    }
    else {
        if (alsa_in_direct.prepare() != 0) {
            fprintf(stderr, "Alsa preparation failed\n");
            return 1;
        }
    }

    int outbuf_size = subchannel_index*120;
    uint8_t zmqframebuf[ZMQ_HEADER_SIZE + 24*120];
    zmq_frame_header_t *zmq_frame_header = (zmq_frame_header_t*)zmqframebuf;

    uint8_t outbuf[24*120];

    unsigned char pad_buf[padlen + 1];

    if(outbuf_size % 5 != 0) {
        fprintf(stderr, "(outbuf_size mod 5) = %d\n", outbuf_size % 5);
    }

    fprintf(stderr, "Starting encoding\n");

    int retval = 0;
    int send_error_count = 0;
    struct timespec tp_next;
    clock_gettime(CLOCK_MONOTONIC, &tp_next);

    int calls = 0; // for checking
    while (1) {
        int in_identifier[] = {IN_AUDIO_DATA, IN_ANCILLRY_DATA};
        int out_identifier = OUT_BITSTREAM_DATA;

        AACENC_BufDesc in_buf = { 0 }, out_buf = { 0 };
        AACENC_InArgs in_args = { 0 };
        AACENC_OutArgs out_args = { 0 };
        void *in_ptr[2], *out_ptr;
        int in_size[2], in_elem_size[2];
        int out_size, out_elem_size;


        // -------------- wait the right amount of time
        if (drift_compensation || jack_name) {
            struct timespec tp_now;
            clock_gettime(CLOCK_MONOTONIC, &tp_now);

            unsigned long time_now  = (1000000000ul * tp_now.tv_sec) +
                tp_now.tv_nsec;
            unsigned long time_next = (1000000000ul * tp_next.tv_sec) +
                tp_next.tv_nsec;

            const unsigned long dabplus_superframe_nsec = 120000000ul;

            const unsigned long wait_time =
                dabplus_superframe_nsec / enc_calls_per_output;

            unsigned long waiting = wait_time - (time_now - time_next);
            if ((time_now - time_next) < wait_time) {
                //printf("Sleep %zuus\n", waiting / 1000);
                usleep(waiting / 1000);
            }

            // Move our time_counter into the future, for
            // the next frame.
            tp_next.tv_nsec += wait_time;
            if (tp_next.tv_nsec >  1000000000L) {
                tp_next.tv_nsec -= 1000000000L;
                tp_next.tv_sec  += 1;
            }
        }

        // --------------- Read data from the PAD fifo
        int ret;
        if (padlen != 0) {
            ret = read(pad_fd, pad_buf, padlen + 1);
        }
        else {
            ret = 0;
        }


        if(ret < 0 && errno == EAGAIN) {
            // If this condition passes, there is no data to be read
            in_buf.numBufs = 1;    // Samples;
        }
        else if(ret >= 0) {
            // Otherwise, you're good to go and buffer should contain "count" bytes.
            in_buf.numBufs = 2;    // Samples + Data;
            if (ret > 0)
                status |= STATUS_PAD_INSERTED;
        }
        else {
            // Some other error occurred during read.
            fprintf(stderr, "Unable to read from PAD!\n");
                        break;
        }

        // -------------- Read Data
        memset(outbuf, 0x00, outbuf_size);
        memset(input_buf, 0x00, input_size);

        ssize_t read;
        if (infile) {
            read = file_in.read(input_buf, input_size);
            if (read < 0) {
                break;
            }
            else if (read != input_size) {
                if (inFifoSilence && file_in.eof()) {
                    memset(input_buf, 0, input_size);
                    read = input_size;
                    usleep((long)input_size * 1000000 /
                            (BYTES_PER_SAMPLE * channels * sample_rate));
                }
                else {
                    fprintf(stderr, "Short file read !\n");
                    break;
                }
            }
        }
#if HAVE_VLC
        else if (not vlc_uri.empty()) {
            VLCInput* vlc_in = nullptr;

            if (drift_compensation) {
                vlc_in = &vlc_in_threaded;

                if (drift_compensation && vlc_in_threaded.fault_detected()) {
                    fprintf(stderr, "Detected fault in VLC input!\n");
                    retval = 5;
                    break;
                }

                size_t overruns;
                read = queue.pop(input_buf, input_size, &overruns); // returns bytes

                if (read != input_size) {
                    status |= STATUS_UNDERRUN;
                }

                if (overruns) {
                    status |= STATUS_OVERRUN;
                }
            }
            else {
                vlc_in = &vlc_in_direct;

                read = vlc_in_direct.read(input_buf, input_size);
                if (read < 0) {
                    fprintf(stderr, "Detected fault in VLC input!\n");
                    break;
                }
                else if (read != input_size) {
                    fprintf(stderr, "Short VLC read !\n");
                    break;
                }
            }

            if (not vlc_icytext_file.empty()) {
                vlc_in->write_icy_text(vlc_icytext_file);
            }
        }
#endif
        else if (drift_compensation || jack_name) {
            if (drift_compensation && alsa_in_threaded.fault_detected()) {
                fprintf(stderr, "Detected fault in alsa input!\n");
                retval = 5;
                break;
            }

            size_t overruns;
            read = queue.pop(input_buf, input_size, &overruns); // returns bytes

            if (read != input_size) {
                status |= STATUS_UNDERRUN;
            }

            if (overruns) {
                status |= STATUS_OVERRUN;
            }
        }
        else {
            read = alsa_in_direct.read(input_buf, input_size);
            if (read < 0) {
                break;
            }
            else if (read != input_size) {
                fprintf(stderr, "Short alsa read !\n");
            }
        }

        for (int i = 0; i < read; i+=4) {
            int16_t l = input_buf[i] | (input_buf[i+1] << 8);
            int16_t r = input_buf[i+2] | (input_buf[i+3] << 8);
            peak_left  = MAX(peak_left,  l);
            peak_right = MAX(peak_right, r);
        }

        /* Silence detection */
        if (die_on_silence && MAX(peak_left, peak_right) == 0) {
            const unsigned int dabplus_superframe_msec = 120ul;
            const unsigned int frame_time_msec =
                dabplus_superframe_msec / enc_calls_per_output;

            measured_silence_ms += frame_time_msec;

            if (measured_silence_ms > 1000*silence_timeout) {
                fprintf(stderr, "Silence detected for %d seconds, aborting.\n",
                        silence_timeout);
                retval = 2;
                break;
            }
        }
        else {
            measured_silence_ms = 0;
        }

        // -------------- AAC Encoding

        int calculated_padlen = ret > 0 ? pad_buf[padlen] : 0;


        in_ptr[0] = input_buf;
        in_ptr[1] = pad_buf + (padlen - calculated_padlen); // offset due to unused PAD bytes
        in_size[0] = read;
        in_size[1] = calculated_padlen;
        in_elem_size[0] = BYTES_PER_SAMPLE;
        in_elem_size[1] = sizeof(uint8_t);
        in_args.numInSamples = input_size/BYTES_PER_SAMPLE;
        in_args.numAncBytes = calculated_padlen;

        in_buf.bufs = (void**)&in_ptr;
        in_buf.bufferIdentifiers = in_identifier;
        in_buf.bufSizes = in_size;
        in_buf.bufElSizes = in_elem_size;

        out_ptr = outbuf;
        out_size = sizeof(outbuf);
        out_elem_size = 1;
        out_buf.numBufs = 1;
        out_buf.bufs = &out_ptr;
        out_buf.bufferIdentifiers = &out_identifier;
        out_buf.bufSizes = &out_size;
        out_buf.bufElSizes = &out_elem_size;

        AACENC_ERROR err;
        if ((err = aacEncEncode(encoder, &in_buf, &out_buf, &in_args, &out_args))
                != AACENC_OK) {
            if (err == AACENC_ENCODE_EOF) {
                fprintf(stderr, "encoder error: EOF reached\n");
                break;
            }
            fprintf(stderr, "Encoding failed (%d)\n", err);
            retval = 3;
            break;
        }
        calls++;

        /* Check if the encoder has generated output data */
        if (out_args.numOutBytes != 0)
        {
            // Our timing code depends on this
            if (calls != enc_calls_per_output) {
                fprintf(stderr, "INTERNAL ERROR! calls=%d"
                        ", expected %d\n",
                        calls, enc_calls_per_output);
            }
            calls = 0;

            // ----------- RS encoding
            int row, col;
            unsigned char buf_to_rs_enc[110];
            unsigned char rs_enc[10];
            for(row=0; row < subchannel_index; row++) {
                for(col=0;col < 110; col++) {
                    buf_to_rs_enc[col] = outbuf[subchannel_index * col + row];
                }

                encode_rs_char(rs_handler, buf_to_rs_enc, rs_enc);

                for(col=110; col<120; col++) {
                    outbuf[subchannel_index * col + row] = rs_enc[col-110];
                    assert(subchannel_index * col + row < outbuf_size);
                }
            }

            if (out_fh) {
                fwrite(outbuf, 1, outbuf_size, out_fh);
            }
            else {
                // ------------ ZeroMQ transmit
                try {
                    zmq_frame_header->version = 1;
                    zmq_frame_header->encoder = ZMQ_ENCODER_FDK;
                    zmq_frame_header->datasize = outbuf_size;
                    zmq_frame_header->audiolevel_left = peak_left;
                    zmq_frame_header->audiolevel_right = peak_right;

                    assert(ZMQ_FRAME_SIZE(zmq_frame_header) <= NUMOF(zmqframebuf));

                    memcpy(ZMQ_FRAME_DATA(zmq_frame_header),
                            outbuf, outbuf_size);

                    zmq_sock.send(zmqframebuf, ZMQ_FRAME_SIZE(zmq_frame_header),
                            ZMQ_DONTWAIT);
                }
                catch (zmq::error_t& e) {
                    fprintf(stderr, "ZeroMQ send error !\n");
                    send_error_count ++;
                }

                if (send_error_count > 10)
                {
                    fprintf(stderr, "ZeroMQ send failed ten times, aborting!\n");
                    retval = 4;
                    break;
                }
            }

            if (show_level) {
                if (channels == 1) {
                    fprintf(stderr, "\rIn: [%-6s] %1s %1s %1s",
                            level(1, MAX(peak_right, peak_left)),
                            status & STATUS_PAD_INSERTED ? "P" : " ",
                            status & STATUS_UNDERRUN ? "U" : " ",
                            status & STATUS_OVERRUN ? "O" : " ");
                }
                else if (channels == 2) {
                    fprintf(stderr, "\rIn: [%6s|%-6s] %1s %1s %1s",
                            level(0, peak_left),
                            level(1, peak_right),
                            status & STATUS_PAD_INSERTED ? "P" : " ",
                            status & STATUS_UNDERRUN ? "U" : " ",
                            status & STATUS_OVERRUN ? "O" : " ");
                }

                peak_right = 0;
                peak_left = 0;
            }
            else {
                if (status & STATUS_OVERRUN) {
                    fprintf(stderr, "O");
                }

                if (status & STATUS_UNDERRUN) {
                    fprintf(stderr, "U");
                }

            }

            status = 0;
        }

        fflush(stdout);
    }
    fprintf(stderr, "\n");

    if (out_fh) {
        fclose(out_fh);
    }

    zmq_sock.close();
    free_rs_char(rs_handler);

    aacEncClose(&encoder);

    return retval;
}