/*
    DeaDBeeF -- the music player
    Copyright (C) 2009-2016 Oleksiy Yakovenko and other contributors

    This software is provided 'as-is', without any express or implied
    warranty.  In no event will the authors be held liable for any damages
    arising from the use of this software.

    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute it
    freely, subject to the following restrictions:

    1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.

    2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.

    3. This notice may not be removed or altered from any source distribution.
*/

#include <string.h>
#include <stdio.h>
#include <unistd.h>
#ifdef HAVE_CONFIG_H
#include "../../config.h"
#endif
#include <stdlib.h>
#include <math.h>
#include "../../deadbeef.h"
#include "../../strdupa.h"
#include "aac_parser.h"
#include "aac_decoder_faad2.h"

#include "../../shared/mp4tagutil.h"

#define min(x,y) ((x)<(y)?(x):(y))
#define max(x,y) ((x)>(y)?(x):(y))

#define trace(...) { deadbeef->log_detailed (&plugin.decoder.plugin, 0, __VA_ARGS__); }

static ddb_decoder2_t plugin;
DB_functions_t *deadbeef;

#define AAC_MAX_PACKET_SIZE 768*8 // setting max input packet size, to have some headroom

#define MP4FILE mp4ff_t *
#define MP4FILE_CB mp4ff_callback_t

#define RAW_AAC_PROBE_SIZE 100

// aac channel mapping
// 0: Defined in AOT Specifc Config
// 1: 1 channel: front-center
// 2: 2 channels: front-left, front-right
// 3: 3 channels: front-center, front-left, front-right
// 4: 4 channels: front-center, front-left, front-right, back-center
// 5: 5 channels: front-center, front-left, front-right, back-left, back-right
// 6: 6 channels: front-center, front-left, front-right, back-left, back-right, LFE-channel
// 7: 8 channels: front-center, front-left, front-right, side-left, side-right, back-left, back-right, LFE-channel
// 8-15: Reserved

// aac channels
#define FRONT_CHANNEL_CENTER (1)
#define FRONT_CHANNEL_LEFT   (2)
#define FRONT_CHANNEL_RIGHT  (3)
#define SIDE_CHANNEL_LEFT    (4)
#define SIDE_CHANNEL_RIGHT   (5)
#define BACK_CHANNEL_LEFT    (6)
#define BACK_CHANNEL_RIGHT   (7)
#define BACK_CHANNEL_CENTER  (8)
#define LFE_CHANNEL          (9)
#define UNKNOWN_CHANNEL      (0)


typedef struct {
    DB_fileinfo_t info;
    aacDecoderHandle_t *dec;
    aacDecoderFrameInfo_t frame_info;
    DB_FILE *file;

    mp4p_file_callbacks_t mp4reader;
    mp4p_atom_t *mp4file;
    mp4p_atom_t *trak;
    uint64_t mp4samples;
    uint32_t aac_samplerate;

    int mp4sample;
    int mp4framesize;
    int64_t skipsamples;
    int64_t startsample;
    int64_t endsample;
    int64_t currentsample;

    // buffer with input packet data
    uint8_t buffer[AAC_MAX_PACKET_SIZE];
    int remaining;

    // buffer with decoded samples
    uint8_t *out_buffer;
    size_t out_buffer_size;
    int out_remaining;
    int num_errors;
    char *samplebuffer;
    int remap[10];
    int noremap;
    int eof;
    int junk;
} aac_info_t;

static int
aac_seek_sample (DB_fileinfo_t *_info, int sample);

// allocate codec control structure
static DB_fileinfo_t *
aac_open (uint32_t hints) {
    aac_info_t *info = calloc (1, sizeof (aac_info_t));
    return (DB_fileinfo_t *)info;
}

static int64_t
parse_aac_stream(DB_FILE *fp, int *psamplerate, int *pchannels, float *pduration, int64_t *ptotalsamples)
{
    size_t framepos = deadbeef->ftell (fp);
    int64_t firstframepos = -1;
    int64_t fsize = -1;
    int offs = 0;

    if (!fp->vfs->is_streaming ()) {
        fsize = deadbeef->fgetlength (fp) - deadbeef->ftell(fp);
    }

    uint8_t buf[ADTS_HEADER_SIZE*8];

    int nsamples = 0;
    int stream_sr = 0;
    int stream_ch = 0;

    int bufsize = 0;

    int frame = 0;
    int scanframes = 1000;
    if (fp->vfs->is_streaming ()) {
        scanframes = 1;
    }

    do {
        int size = sizeof (buf) - bufsize;
        if (deadbeef->fread (buf + bufsize, 1, size, fp) != size) {
            break;
        }
        bufsize = sizeof (buf);

        int channels, samplerate, bitrate, samples;
        size = aac_sync (buf, &channels, &samplerate, &bitrate, &samples);
        if (size == 0) {
            memmove (buf, buf+1, sizeof (buf)-1);
            bufsize--;
            framepos++;
            continue;
        }
        else {
            frame++;
            nsamples += samples;
            if (!stream_sr) {
                stream_sr = samplerate;
            }
            if (!stream_ch) {
                stream_ch = channels;
            }
            if (firstframepos == -1) {
                firstframepos = framepos;
            }
//            if (fp->vfs->streaming) {
//                *psamplerate = stream_sr;
//                *pchannels = stream_ch;
//            }
            framepos += size;
            if (deadbeef->fseek (fp, size-(int)sizeof(buf), SEEK_CUR) == -1) {
                break;
            }
            bufsize = 0;
        }
    } while (ptotalsamples || frame < scanframes);

    if (!frame || !stream_sr || !nsamples) {
        return -1;
    }

    *psamplerate = stream_sr;

    *pchannels = stream_ch;

    if (ptotalsamples) {
        *ptotalsamples = nsamples;
        *pduration = nsamples / (float)stream_sr;
    }
    else {
        int64_t pos = deadbeef->ftell (fp);
        int totalsamples = (double)fsize / (pos-offs) * nsamples;
        *pduration = totalsamples / (float)stream_sr;
    }

    if (*psamplerate <= 24000) {
        *psamplerate *= 2;
        if (ptotalsamples) {
            *ptotalsamples *= 2;
        }
    }
    return firstframepos;
}

// returns -1 for error, 0 for aac
static int
aac_probe (DB_FILE *fp, float *duration, int *samplerate, int *channels, int64_t *totalsamples) {
    deadbeef->rewind (fp);
    if (!fp->vfs->is_streaming ()) {
        int skip = deadbeef->junk_get_leading_size (fp);
        if (skip >= 0) {
            deadbeef->fseek (fp, skip, SEEK_CUR);
        }
    }

    if (parse_aac_stream (fp, samplerate, channels, duration, totalsamples) == -1) {
        return -1;
    }
    return 0;
}

static int
aac_init (DB_fileinfo_t *_info, DB_playItem_t *it) {
    aac_info_t *info = (aac_info_t *)_info;

    deadbeef->pl_lock ();
    const char *uri = strdupa (deadbeef->pl_find_meta (it, ":URI"));
    deadbeef->pl_unlock ();
    info->file = deadbeef->fopen (uri);
    if (!info->file) {
        return -1;
    }

    // probe
    if (!info->file->vfs->is_streaming ()) {
        info->junk = deadbeef->junk_get_leading_size (info->file);
        if (info->junk >= 0) {
            deadbeef->fseek (info->file, info->junk, SEEK_SET);
        }
        else {
            info->junk = 0;
        }
    }
    else {
        deadbeef->fset_track (info->file, it);
    }

    info->mp4reader.ptrhandle = info->file;
    mp4_init_ddb_file_callbacks (&info->mp4reader);
    info->mp4file = mp4p_open(&info->mp4reader);

    int64_t totalsamples = -1;
    float duration = -1;
    mp4p_mp4a_t *aac = NULL;

    if (info->mp4file) {
        info->trak = mp4p_atom_find (info->mp4file, "moov/trak");
        while (info->trak) {
            mp4p_atom_t *aac_atom = mp4p_atom_find (info->trak, "trak/mdia/minf/stbl/stsd/mp4a");
            if (aac_atom) {
                aac = aac_atom->data;
                info->aac_samplerate = aac->sample_rate;
                break;
            }
            info->trak = info->trak->next;
        }

        if (!aac) {
            if (info->mp4file) {
                mp4p_atom_free_list (info->mp4file);
                info->mp4file = NULL;
            }
        }
    }

    if (aac) {
        mp4p_atom_t *stts_atom = mp4p_atom_find(info->trak, "trak/mdia/minf/stbl/stts");

        uint64_t total_sample_duration = mp4p_stts_total_sample_duration (stts_atom);
        mp4p_atom_t *stsz_atom = mp4p_atom_find(info->trak, "trak/mdia/minf/stbl/stsz");
        mp4p_stsz_t *stsz = stsz_atom->data;

        // init mp4 decoding
        info->mp4samples = stsz->number_of_entries;
        info->dec = aacDecoderOpenFAAD2();
        unsigned samplerate;
        unsigned channels;

        mp4p_atom_t *esds_atom = mp4p_atom_find (info->trak, "trak/mdia/minf/stbl/stsd/mp4a/esds");
        if (!esds_atom) {
            return -1;
        }
        mp4p_esds_t *esds = esds_atom->data;

        uint8_t *asc = (uint8_t *)esds->asc;
        if (aacDecoderInit(info->dec, asc, esds->asc_size, &samplerate, &channels) < 0) {
            return -1;
        }
        totalsamples = total_sample_duration * samplerate / info->aac_samplerate;
        duration = total_sample_duration / (float)info->aac_samplerate;

        _info->fmt.samplerate = samplerate;
        _info->fmt.channels = channels;
    }
    else if (info->mp4file) {
        return -1; // mp4 but not aac
    }
    else {
        int samplerate = -1;
        int channels = -1;
        int64_t offs;
        if (!info->file->vfs->is_streaming ()) {
            if (info->junk >= 0) {
                deadbeef->fseek (info->file, info->junk, SEEK_SET);
            }
            else {
                deadbeef->rewind (info->file);
            }
            offs = parse_aac_stream (info->file, &samplerate, &channels, &duration, &totalsamples);
        }
        else {
            offs = parse_aac_stream (info->file, &samplerate, &channels, &duration, NULL);
        }
        if (offs == -1) {
            return -1;
        }
        if (offs > info->junk) {
            info->junk = (int)offs;
        }
        if (!info->file->vfs->is_streaming ()) {
            if (info->junk >= 0) {
                deadbeef->fseek (info->file, info->junk, SEEK_SET);
            }
            else {
                deadbeef->rewind (info->file);
            }
        }
        if (info->file->vfs->is_streaming ()) {
            deadbeef->pl_replace_meta (it, "!FILETYPE", "AAC");
        }

        off_t fileOffs = deadbeef->ftell (info->file);
        uint8_t asc[RAW_AAC_PROBE_SIZE];
        size_t nb = deadbeef->fread (asc, 1, sizeof (asc), info->file);
        if (nb != sizeof (asc)) {
            return -1;
        }
        deadbeef->fseek (info->file, fileOffs, SEEK_SET);
        unsigned usamplerate;
        unsigned uchannels;

        info->dec = aacDecoderOpenFAAD2();
        if (aacDecoderInitRaw(info->dec, asc, sizeof (asc), &usamplerate, &uchannels) < 0) {
            return -1;
        }
        _info->fmt.samplerate = usamplerate;
        _info->fmt.channels = uchannels;
    }

    _info->fmt.bps = 16;
    _info->plugin = &plugin.decoder;

    if (!info->file->vfs->is_streaming ()) {
        int64_t endsample = deadbeef->pl_item_get_endsample(it);
        if (endsample > 0) {
            info->startsample = deadbeef->pl_item_get_startsample(it);
            info->endsample = endsample;
            aac_seek_sample (_info, 0);
        }
        else {
            info->startsample = 0;
            info->endsample = (int)totalsamples-1;
        }
    }
    if (_info->fmt.channels == 7) {
        _info->fmt.channels = 8;
    }

    char s[100];
    deadbeef->pl_replace_meta (it, ":BPS", "16");
    snprintf (s, sizeof (s), "%d", _info->fmt.channels);
    deadbeef->pl_replace_meta (it, ":CHANNELS", s);
    snprintf (s, sizeof (s), "%d", _info->fmt.samplerate);
    deadbeef->pl_replace_meta (it, ":SAMPLERATE", s);

    trace ("totalsamples: %d, endsample: %d, samples-from-duration: %d, samplerate %d, channels %d\n", (int)totalsamples, (int)info->endsample, (int)deadbeef->pl_get_item_duration (it)*44100, _info->fmt.samplerate, _info->fmt.channels);

    for (int i = 0; i < _info->fmt.channels; i++) {
        _info->fmt.channelmask |= 1 << i;
    }
    info->noremap = 0;
    for (int i = 0; i < sizeof (info->remap) / sizeof (int); i++) {
        info->remap[i] = -1;
    }

    return 0;
}

static void
aac_free (DB_fileinfo_t *_info) {
    aac_info_t *info = (aac_info_t *)_info;
    if (info) {
        if (info->file) {
            deadbeef->fclose (info->file);
        }
        if (info->mp4file) {
            mp4p_atom_free_list (info->mp4file);
        }
        if (info->dec) {
            aacDecoderClose (info->dec);
        }
        free (info->out_buffer);
        free (info);
    }
}

static int
aac_read (DB_fileinfo_t *_info, char *bytes, int size) {
    aac_info_t *info = (aac_info_t *)_info;
    if (info->eof) {
        return 0;
    }

    int samplesize = _info->fmt.channels * _info->fmt.bps / 8;
    if (!info->file->vfs->is_streaming ()) {
        if (info->currentsample + size / samplesize > info->endsample) {
            size = (int)(info->endsample - info->currentsample + 1) * samplesize;
            if (size <= 0) {
                return 0;
            }
        }
    }

    int initsize = size;

    size_t bitrate_bytes = 0;
    size_t bitrate_samples = 0;

    while (size > 0) {
        // skip decoded samples
        if (info->skipsamples > 0 && info->out_remaining > 0) {
            int64_t skip = min (info->out_remaining, info->skipsamples);
            if (skip < info->out_remaining) {
                memmove (info->out_buffer, info->out_buffer + skip * samplesize, (info->out_remaining - skip) * samplesize);
            }
            info->out_remaining -= skip;
            info->skipsamples -= skip;
        }

        // consume decoded samples
        if (info->out_remaining > 0) {
            int n = size / samplesize;
            n = min (info->out_remaining, n);

            uint8_t *src = info->out_buffer;
            if (info->noremap) {
                memcpy (bytes, src, n * samplesize);
                bytes += n * samplesize;
                src += n * samplesize;
            }
            else {
                int i, j;
                if (info->remap[0] == -1) {
                    // build remap mtx
                    // FIXME: should build channelmask 1st; then remap based on channelmask
                    for (i = 0; i < _info->fmt.channels; i++) {
                        switch (info->frame_info.channel_position[i]) {
                        case FRONT_CHANNEL_CENTER:
                            trace ("FC->%d %d\n", i, 2);
                            info->remap[2] = i;
                            break;
                        case FRONT_CHANNEL_LEFT:
                            trace ("FL->%d %d\n", i, 0);
                            info->remap[0] = i;
                            break;
                        case FRONT_CHANNEL_RIGHT:
                            trace ("FR->%d %d\n", i, 1);
                            info->remap[1] = i;
                            break;
                        case SIDE_CHANNEL_LEFT:
                            trace ("SL->%d %d\n", i, 6);
                            info->remap[6] = i;
                            break;
                        case SIDE_CHANNEL_RIGHT:
                            trace ("SR->%d %d\n", i, 7);
                            info->remap[7] = i;
                            break;
                        case BACK_CHANNEL_LEFT:
                            trace ("RL->%d %d\n", i, 4);
                            info->remap[4] = i;
                            break;
                        case BACK_CHANNEL_RIGHT:
                            trace ("RR->%d %d\n", i, 5);
                            info->remap[5] = i;
                            break;
                        case BACK_CHANNEL_CENTER:
                            trace ("BC->%d %d\n", i, 8);
                            info->remap[8] = i;
                            break;
                        case LFE_CHANNEL:
                            trace ("LFE->%d %d\n", i, 3);
                            info->remap[3] = i;
                            break;
                        default:
                            trace ("aac: unknown ch(%d)->%d\n", info->frame_info.channel_position[i], i);
                            break;
                        }
                    }
                    for (i = 0; i < _info->fmt.channels; i++) {
                        trace ("%d ", info->remap[i]);
                    }
                    trace ("\n");
                    if (info->remap[0] == -1) {
                        info->remap[0] = 0;
                    }
                    if ((_info->fmt.channels == 1 && info->remap[0] == FRONT_CHANNEL_CENTER)
                        || (_info->fmt.channels == 2 && info->remap[0] == FRONT_CHANNEL_LEFT && info->remap[1] == FRONT_CHANNEL_RIGHT)) {
                        info->noremap = 1;
                    }
                }

                for (i = 0; i < n; i++) {
                    for (j = 0; j < _info->fmt.channels; j++) {
                        if (info->remap[j] == -1) {
                            ((int16_t *)bytes)[j] = 0;
                        }
                        else {
                            ((int16_t *)bytes)[j] = ((int16_t *)src)[info->remap[j]];
                        }
                    }
                    src += samplesize;
                    bytes += samplesize;
                }
            }
            size -= n * samplesize;

            if (n == info->out_remaining) {
                info->out_remaining = 0;
            }
            else {
                memmove (info->out_buffer, src, (info->out_remaining - n) * samplesize);
                info->out_remaining -= n;
            }
            continue;
        }

        uint8_t *samples = NULL;

        if (info->mp4file) {
            if (info->mp4sample >= info->mp4samples) {
                break;
            }

            mp4p_atom_t *stbl_atom = mp4p_atom_find(info->trak, "trak/mdia/minf/stbl");
            uint64_t offs = mp4p_sample_offset (stbl_atom, info->mp4sample);
            unsigned int size = mp4p_sample_size (stbl_atom, info->mp4sample);
//            printf ("%08X %d\n", (int)offs, size);

            uint8_t *mp4packet = malloc (size);
            deadbeef->fseek (info->file, offs+info->junk, SEEK_SET);
            if (size != deadbeef->fread (mp4packet, 1, size, info->file)) {
                trace ("aac: failed to read sample\n");
                info->eof = 1;
                break;
            }
            info->mp4sample++;

            samples = aacDecoderDecodeFrame (info->dec, &info->frame_info, mp4packet, size);

            free (mp4packet);
            mp4packet = NULL;

            if (!samples) {
                trace ("aac: ascDecoderDecodeFrame returned NULL\n");
                break;
            }

            bitrate_bytes += info->frame_info.bytesconsumed;
            bitrate_samples += info->frame_info.samples / info->frame_info.channels;
        }
        else {
            if (info->remaining < AAC_MAX_PACKET_SIZE) {
                trace ("fread from offs %lld\n", deadbeef->ftell (info->file));
                size_t res = deadbeef->fread (info->buffer + info->remaining, 1, AAC_MAX_PACKET_SIZE-info->remaining, info->file);
                info->remaining += res;
                trace ("remain: %d\n", info->remaining);
                if (!info->remaining) {
                    break;
                }
            }
            trace ("NeAACDecDecode %d bytes\n", info->remaining)
            samples = aacDecoderDecodeFrame (info->dec, &info->frame_info, info->buffer, info->remaining);
            bitrate_bytes += info->frame_info.bytesconsumed;
            bitrate_samples += info->frame_info.channels > 0 ? info->frame_info.samples / info->frame_info.channels : 0;
            trace ("samples =%p\n", samples);
            if (!samples) {
//                trace ("NeAACDecDecode failed with error %s (%d), consumed=%d\n", NeAACDecGetErrorMessage(info->frame_info.error), (int)info->frame_info.error, (int)info->frame_info.bytesconsumed);
                if (info->num_errors > 10) {
                    trace ("NeAACDecDecode failed %d times, interrupting\n", info->num_errors);
                    break;
                }
                info->num_errors++;
                info->remaining = 0;
                continue;
            }
            info->num_errors=0;
            unsigned long consumed = info->frame_info.bytesconsumed;
            if (consumed > info->remaining) {
                trace ("NeAACDecDecode consumed more than available! wtf?\n");
                break;
            }
            if (consumed == info->remaining) {
                info->remaining = 0;
            }
            else if (consumed > 0) {
                memmove (info->buffer, info->buffer + consumed, info->remaining - consumed);
                info->remaining -= consumed;
            }
        }

        if (info->frame_info.samples > 0) {
            if (info->out_buffer_size < info->frame_info.samples * 2) {
                info->out_buffer_size = info->frame_info.samples * 2;
                info->out_buffer = realloc (info->out_buffer, info->out_buffer_size);
            }
            memcpy (info->out_buffer, samples, info->frame_info.samples * 2);
            info->out_remaining = (int)(info->frame_info.samples / info->frame_info.channels);
        }
    }

    info->currentsample += (initsize-size) / samplesize;
    long bitrate = 0;
    if (bitrate_samples > 0) {
        bitrate = bitrate_bytes * 8 * _info->fmt.samplerate / bitrate_samples / 1000;
    }
    deadbeef->streamer_set_bitrate ((int)bitrate);

    return initsize-size;
}

// returns -1 on error, skipsamples on success
int64_t
seek_raw_aac (aac_info_t *info, int64_t sample) {
    uint8_t buf[ADTS_HEADER_SIZE*8];

    int bufsize = 0;

    int frame = 0;

    int frame_samples = 0;
    int curr_sample = 0;

    do {
        curr_sample += frame_samples;
        int size = sizeof (buf) - bufsize;
        if (deadbeef->fread (buf + bufsize, 1, size, info->file) != size) {
            break;
        }
        bufsize = sizeof (buf);

        int channels, samplerate, bitrate;
        size = aac_sync (buf, &channels, &samplerate, &bitrate, &frame_samples);
        if (size == 0) {
            memmove (buf, buf+1, sizeof (buf)-1);
            bufsize--;
            continue;
        }
        else {
            frame++;
            if (deadbeef->fseek (info->file, size-(int)sizeof(buf), SEEK_CUR) == -1) {
                break;
            }
            bufsize = 0;
        }
        if (samplerate <= 24000) {
            frame_samples *= 2;
        }
    } while (curr_sample + frame_samples < sample);

    if (curr_sample + frame_samples < sample) {
        return -1;
    }

    return sample - curr_sample;
}

static int
aac_seek_sample64 (DB_fileinfo_t *_info, int64_t sample) {
    aac_info_t *info = (aac_info_t *)_info;

    sample += info->startsample;

    if (info->mp4file) {
        mp4p_atom_t *stts_atom = mp4p_atom_find(info->trak, "trak/mdia/minf/stbl/stts");

        uint64_t seeksample = (int)(sample * info->aac_samplerate / _info->fmt.samplerate);

        uint64_t startsample = 0;
        info->mp4sample = mp4p_stts_mp4sample_containing_sample(stts_atom, seeksample, &startsample);

        startsample = startsample * _info->fmt.samplerate / info->aac_samplerate;
        info->skipsamples = sample - startsample;
    }
    else {
        int skip = deadbeef->junk_get_leading_size (info->file);
        if (skip >= 0) {
            deadbeef->fseek (info->file, skip, SEEK_SET);
        }
        else {
            deadbeef->fseek (info->file, 0, SEEK_SET);
        }

        int64_t res = seek_raw_aac (info, sample);
        if (res < 0) {
            return -1;
        }
        info->skipsamples = res;
    }
    info->remaining = 0;
    info->out_remaining = 0;
    info->currentsample = sample;
    _info->readpos = (float)(info->currentsample - info->startsample) / _info->fmt.samplerate;

    return 0;
}

static int
aac_seek_sample (DB_fileinfo_t *_info, int sample) {
    return aac_seek_sample64(_info, sample);
}

static int
aac_seek (DB_fileinfo_t *_info, float t) {
    return aac_seek_sample64 (_info, (float)((double)t * (int64_t)_info->fmt.samplerate));
}

typedef struct {
    char *title;
    int64_t startsample;
    int64_t endsample;
} aac_chapter_t;

static aac_chapter_t *
aac_load_itunes_chapters (aac_info_t *info, mp4p_chap_t *chap, /* out */ int *num_chapters, int samplerate) {
    *num_chapters = 0;

    mp4p_atom_t *mp4 = info->mp4file;

    for (int i = 0; i < chap->number_of_entries; i++)
    {
        mp4p_atom_t *text_atom = NULL;
        mp4p_atom_t *trak_atom = mp4p_atom_find(mp4, "moov/trak");
        while (trak_atom) {
            text_atom = NULL;
            if (!mp4p_atom_type_compare(trak_atom, "trak") && mp4p_trak_has_chapters(trak_atom)) {
                text_atom = mp4p_atom_find(trak_atom, "trak/mdia/minf/stbl/stsd/text");
                mp4p_atom_t *tkhd_atom = mp4p_atom_find(trak_atom, "trak/tkhd");
                if (text_atom && tkhd_atom) {
                    mp4p_tkhd_t *tkhd = tkhd_atom->data;
                    if (tkhd->track_id == chap->entries[i]) {
                        break;
                    }
                }
            }
            trak_atom = trak_atom->next;
        }

        if (!text_atom) {
            continue;
        }

        mp4p_atom_t *stts_atom = mp4p_atom_find(trak_atom, "trak/mdia/minf/stbl/stts");
        mp4p_atom_t *mdhd_atom = mp4p_atom_find(trak_atom, "trak/mdia/mdhd");
        mp4p_atom_t *stbl_atom = mp4p_atom_find(trak_atom, "trak/mdia/minf/stbl");
        mp4p_atom_t *stsz_atom = mp4p_atom_find(stbl_atom, "stbl/stsz");
        if (stts_atom == NULL || mdhd_atom == NULL || stbl_atom == NULL || stsz_atom == NULL) {
            return NULL;
        }

        mp4p_mdhd_t *mdhd = mdhd_atom->data;
        mp4p_stsz_t *stsz = stsz_atom->data;

        if (mdhd->time_scale == 0) {
            return NULL;
        }

        aac_chapter_t *chapters = calloc (stsz->number_of_entries, sizeof (aac_chapter_t));
        *num_chapters = 0;

        int64_t curr_sample = 0;
        for (int sample = 0; sample < stsz->number_of_entries; sample++)
        {
            unsigned char *buffer = NULL;

            uint64_t offs = mp4p_sample_offset (stbl_atom, sample);
            uint32_t size = mp4p_sample_size (stbl_atom, sample);

            buffer = malloc (size);
            deadbeef->fseek (info->file, offs+info->junk, SEEK_SET);
            if (size != deadbeef->fread (buffer, 1, size, info->file)) {
                free (buffer);
                continue;
            }
            int len = (buffer[0] << 8) | buffer[1];
            len = min (len, size - 2);
            if (len > 0) {
                chapters[*num_chapters].title = strndup ((const char *)&buffer[2], len);
            }
            chapters[*num_chapters].startsample = (int)curr_sample;
            uint64_t samplecount = mp4p_stts_sample_duration(stts_atom, sample) / mdhd->time_scale * samplerate;
            curr_sample += samplecount;
            chapters[*num_chapters].endsample = (int)curr_sample - 1;
            free (buffer);
            (*num_chapters)++;
        }
        return chapters;
    }
    return NULL;
}

static DB_playItem_t *
aac_insert_with_chapters (ddb_playlist_t *plt, DB_playItem_t *after, DB_playItem_t *origin, aac_chapter_t *chapters, int num_chapters, int64_t totalsamples, int samplerate) {
    deadbeef->pl_lock ();
    DB_playItem_t *ins = after;
    for (int i = 0; i < num_chapters; i++) {
        const char *uri = deadbeef->pl_find_meta_raw (origin, ":URI");
        const char *dec = deadbeef->pl_find_meta_raw (origin, ":DECODER");
        const char *ftype= "MP4 AAC";//pl_find_meta_raw (origin, ":FILETYPE");

        DB_playItem_t *it = deadbeef->pl_item_alloc_init (uri, dec);
        deadbeef->pl_set_meta_int (it, ":TRACKNUM", i);
        deadbeef->pl_set_meta_int (it, "TRACK", i);
        // poor-man utf8 check
        if (!chapters[i].title || deadbeef->junk_detect_charset (chapters[i].title)) {
            char s[1000];
            snprintf (s, sizeof (s), "chapter %d", i+1);
            deadbeef->pl_add_meta (it, "title", s);
        }
        else {
            deadbeef->pl_add_meta (it, "title", chapters[i].title);
        }
        deadbeef->pl_item_set_startsample (it, chapters[i].startsample);
        deadbeef->pl_item_set_endsample (it, chapters[i].endsample);
        deadbeef->pl_replace_meta (it, ":FILETYPE", ftype);
        float duration = (float)(chapters[i].endsample - chapters[i].startsample + 1) / samplerate;
        deadbeef->plt_set_item_duration (plt, it, duration);
        after = deadbeef->plt_insert_item (plt, after, it);
        deadbeef->pl_item_unref (it);
    }
    deadbeef->pl_item_ref (after);
    
    DB_playItem_t *first = deadbeef->pl_get_next (ins, PL_MAIN);
    
    if (!first) {
        first = deadbeef->plt_get_first (plt, PL_MAIN);
    }

    if (!first) {
        deadbeef->pl_unlock ();
        return NULL;
    }
    // copy metadata from embedded tags
    uint32_t f = deadbeef->pl_get_item_flags (origin);
    f |= DDB_IS_SUBTRACK;
    deadbeef->pl_set_item_flags (origin, f);
    deadbeef->pl_items_copy_junk (origin, first, after);
    deadbeef->pl_item_unref (first);

    deadbeef->pl_unlock ();
    return after;
}


static int
_mp4_insert(DB_playItem_t **after, const char *fname, DB_FILE *fp, ddb_playlist_t *plt) {
    mp4p_atom_t *mp4 = NULL;
    aac_info_t info = {0};
    info.junk = deadbeef->junk_get_leading_size (fp);
    if (info.junk >= 0) {
        deadbeef->fseek (fp, info.junk, SEEK_SET);
    }
    else {
        info.junk = 0;
    }

    info.file = fp;
    info.mp4reader.ptrhandle = fp;
    mp4_init_ddb_file_callbacks (&info.mp4reader);
    mp4 = info.mp4file = mp4p_open(&info.mp4reader);

    if (!mp4) {
        return -1; // not mp4
    }
    const char *ftype = NULL;
    float duration = -1;

    info.trak = mp4p_atom_find (info.mp4file, "moov/trak");
    mp4p_mp4a_t *aac = NULL;
    while (info.trak) {
        if (mp4p_trak_playable(info.trak)) {
            mp4p_atom_t *aac_atom = mp4p_atom_find (info.trak, "trak/mdia/minf/stbl/stsd/mp4a");
            if (aac_atom) {
                aac = aac_atom->data;
                if (aac->sample_rate != 0) {
                    info.aac_samplerate = aac->sample_rate;
                    break;
                }
                else {
                    aac = NULL;
                }
            }
        }
        info.trak = info.trak->next;
    }
    if (!aac) {
        mp4p_atom_free_list(info.mp4file);
        return 1; // mp4 without aac
    }

    // get audio format: samplerate, bps, channels
    mp4p_atom_t *esds_atom = mp4p_atom_find (info.trak, "trak/mdia/minf/stbl/stsd/mp4a/esds");
    if (!esds_atom) {
        mp4p_atom_free_list(info.mp4file);
        return 1;
    }
    mp4p_esds_t *esds = esds_atom->data;

    info.dec = aacDecoderOpenFAAD2();
    unsigned samplerate;
    unsigned channels;
    uint8_t *asc = (uint8_t *)esds->asc;
    if (aacDecoderInit(info.dec, asc, esds->asc_size, &samplerate, &channels) < 0) {
        mp4p_atom_free_list(info.mp4file);
        aacDecoderClose(info.dec);
        return 1;
    }
    info.info.fmt.samplerate = samplerate;
    info.info.fmt.channels = channels;

    int64_t totalsamples = 0;

    mp4p_atom_t *stts_atom = mp4p_atom_find(info.trak, "trak/mdia/minf/stbl/stts");

    uint64_t total_sample_duration = mp4p_stts_total_sample_duration (stts_atom);
    totalsamples = total_sample_duration * samplerate / info.aac_samplerate;
    duration = total_sample_duration / (float)info.aac_samplerate;

    DB_playItem_t *it = deadbeef->pl_item_alloc_init (fname, plugin.decoder.plugin.id);
    ftype = "MP4 AAC";
    deadbeef->pl_add_meta (it, ":FILETYPE", ftype);
    deadbeef->plt_set_item_duration (plt, it, duration);

    deadbeef->rewind (fp);
    (void)deadbeef->junk_apev2_read (it, fp);
    (void)deadbeef->junk_id3v2_read (it, fp);
    (void)deadbeef->junk_id3v1_read (it, fp);

    int64_t fsize = deadbeef->fgetlength (fp);

    char s[100];
    snprintf (s, sizeof (s), "%lld", fsize);
    deadbeef->pl_add_meta (it, ":FILE_SIZE", s);
    deadbeef->pl_add_meta (it, ":BPS", "16");
    snprintf (s, sizeof (s), "%d", channels);
    deadbeef->pl_add_meta (it, ":CHANNELS", s);
    snprintf (s, sizeof (s), "%d", info.info.fmt.samplerate);
    deadbeef->pl_add_meta (it, ":SAMPLERATE", s);
    int br = (int)roundf(fsize / duration * 8 / 1000);
    snprintf (s, sizeof (s), "%d", br);
    deadbeef->pl_add_meta (it, ":BITRATE", s);

    int num_chapters = 0;
    aac_chapter_t *chapters = NULL;

    mp4p_atom_t *chap_atom = mp4p_atom_find(info.trak, "trak/tref/chap");
    if (chap_atom) {
        mp4p_chap_t *chap = chap_atom->data;
        if (chap->number_of_entries > 0) {
            chapters = aac_load_itunes_chapters (&info, chap, &num_chapters, info.info.fmt.samplerate);
        }
    }

    // embedded chapters
    deadbeef->pl_lock (); // FIXME: the lock can be eliminated, if subtracks are first appended "locally", and only appended to the real playlist at the end
    if (chapters && num_chapters > 0) {
        DB_playItem_t *cue = aac_insert_with_chapters (plt, *after, it, chapters, num_chapters, totalsamples, info.info.fmt.samplerate);
        for (int n = 0; n < num_chapters; n++) {
            if (chapters[n].title) {
                free (chapters[n].title);
            }
        }
        free (chapters);
        chapters = NULL;
        if (cue) {
            mp4p_atom_free_list(info.mp4file);
            deadbeef->pl_item_unref (it);
            deadbeef->pl_item_unref (cue);
            deadbeef->pl_unlock ();
            *after = cue;
            return 0;
        }
    }
    free (chapters);
    chapters = NULL;
    deadbeef->pl_unlock ();

    // embedded cue
    const char *cuesheet = deadbeef->pl_find_meta (it, "cuesheet");
    DB_playItem_t *cue = NULL;

    if (cuesheet) {
        cue = deadbeef->plt_insert_cue_from_buffer (plt, *after, it, (const uint8_t *)cuesheet, (int)strlen (cuesheet), (int)totalsamples, info.info.fmt.samplerate);
        if (cue) {
            mp4p_atom_free_list(info.mp4file);
            deadbeef->pl_item_unref (it);
            deadbeef->pl_item_unref (cue);
            *after = cue;
            return 0;
        }
    }

    cue  = deadbeef->plt_insert_cue (plt, *after, it, (int)totalsamples, info.info.fmt.samplerate);
    if (cue) {
        deadbeef->pl_item_unref (it);
        deadbeef->pl_item_unref (cue);
        *after = cue;
        return 0;
    }

    mp4_load_tags (info.mp4file, it);

    *after = deadbeef->plt_insert_item (plt, *after, it);
    deadbeef->pl_item_unref (it);

    mp4p_atom_free_list(info.mp4file);
    return 0;
}

static DB_playItem_t *
aac_insert (ddb_playlist_t *plt, DB_playItem_t *after, const char *fname) {
    DB_FILE *fp = deadbeef->fopen (fname);
    if (!fp) {
        return NULL;
    }
    if (!fp->vfs->is_streaming ()) {
        int res = _mp4_insert(&after, fname, fp, plt);
        if (res == 0) {
            deadbeef->fclose (fp);
            return after;
        }
        else if (res > 0) { // mp4 but not aac
            deadbeef->fclose (fp);
            return NULL;
        }
    }

    // If mp4 is not detected, try raw aac
    const char *ftype = "RAW AAC";
    int samplerate = 0;
    int channels = 0;
    float duration = -1;
    int64_t totalsamples = 0;
    int res = aac_probe (fp, &duration, &samplerate, &channels, &totalsamples);
    if (res == -1) {
        deadbeef->fclose (fp);
        return NULL;
    }
    DB_playItem_t *it = deadbeef->pl_item_alloc_init (fname, plugin.decoder.plugin.id);
    deadbeef->pl_add_meta (it, ":FILETYPE", ftype);
    deadbeef->plt_set_item_duration (plt, it, duration);

    // read tags
    (void)deadbeef->junk_apev2_read (it, fp);
    (void)deadbeef->junk_id3v2_read (it, fp);
    (void)deadbeef->junk_id3v1_read (it, fp);

    int64_t fsize = deadbeef->fgetlength (fp);

    deadbeef->fclose (fp);

    if (duration > 0) {
        char s[100];
        snprintf (s, sizeof (s), "%lld", fsize);
        deadbeef->pl_add_meta (it, ":FILE_SIZE", s);
        deadbeef->pl_add_meta (it, ":BPS", "16");
        snprintf (s, sizeof (s), "%d", channels);
        deadbeef->pl_add_meta (it, ":CHANNELS", s);
        snprintf (s, sizeof (s), "%d", samplerate);
        deadbeef->pl_add_meta (it, ":SAMPLERATE", s);
        int br = (int)roundf(fsize / duration * 8 / 1000);
        snprintf (s, sizeof (s), "%d", br);
        deadbeef->pl_add_meta (it, ":BITRATE", s);
        // embedded cue
        deadbeef->pl_lock ();
        const char *cuesheet = deadbeef->pl_find_meta (it, "cuesheet");
        DB_playItem_t *cue = NULL;

        if (cuesheet) {
            cue = deadbeef->plt_insert_cue_from_buffer (plt, after, it, (uint8_t *)cuesheet, (int)strlen (cuesheet), (int)totalsamples, samplerate);
            if (cue) {
                deadbeef->pl_item_unref (it);
                deadbeef->pl_item_unref (cue);
                deadbeef->pl_unlock ();
                return cue;
            }
        }
        deadbeef->pl_unlock ();

        cue  = deadbeef->plt_insert_cue (plt, after, it, (int)totalsamples, samplerate);
        if (cue) {
            deadbeef->pl_item_unref (it);
            deadbeef->pl_item_unref (cue);
            return cue;
        }
    }

    after = deadbeef->plt_insert_item (plt, after, it);
    deadbeef->pl_item_unref (it);

    return after;
}

static const char * exts[] = { "aac", "mp4", "m4a", "m4b", NULL };

// define plugin interface
static ddb_decoder2_t plugin = {
    .decoder.plugin.api_vmajor = 1,
    .decoder.plugin.api_vminor = 0,
    .decoder.plugin.version_major = 2,
    .decoder.plugin.version_minor = 0,
//    .decoder.plugin.flags = DDB_PLUGIN_FLAG_LOGGING|DDB_PLUGIN_FLAG_IMPLEMENTS_DECODER2,
    .decoder.plugin.flags = DDB_PLUGIN_FLAG_IMPLEMENTS_DECODER2,
    .decoder.plugin.type = DB_PLUGIN_DECODER,
    .decoder.plugin.id = "aac",
    .decoder.plugin.name = "AAC player",
    .decoder.plugin.descr = "plays aac files, supports raw aac files, as well as mp4 container",
    .decoder.plugin.copyright =
        "AAC DeaDBeeF Player Plugin\n"
        "Copyright (c) 2009-2020 Oleksiy Yakovenko <waker@users.sourceforge.net>\n"
        "\n"
        "This software is provided 'as-is', without any express or implied\n"
        "warranty.  In no event will the authors be held liable for any damages\n"
        "arising from the use of this software.\n"
        "\n"
        "Permission is granted to anyone to use this software for any purpose,\n"
        "including commercial applications, and to alter it and redistribute it\n"
        "freely, subject to the following restrictions:\n"
        "\n"
        "1. The origin of this software must not be misrepresented; you must not\n"
        " claim that you wrote the original software. If you use this software\n"
        " in a product, an acknowledgment in the product documentation would be\n"
        " appreciated but is not required.\n"
        "\n"
        "2. Altered source versions must be plainly marked as such, and must not be\n"
        " misrepresented as being the original software.\n"
        "\n"
        "3. This notice may not be removed or altered from any source distribution.\n"
        "\n"
        "\n"
        "libfaad2 Copyright (c) Nero AG, www.nero.com\n"
        "\n"
        "This program is free software; you can redistribute it and/or\n"
        "modify it under the terms of the GNU General Public License\n"
        "as published by the Free Software Foundation; either version 2\n"
        "of the License, or (at your option) any later version.\n"
        "\n"
        "This program is distributed in the hope that it will be useful,\n"
        "but WITHOUT ANY WARRANTY; without even the implied warranty of\n"
        "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n"
        "GNU General Public License for more details.\n"
        "\n"
        "You should have received a copy of the GNU General Public License\n"
        "along with this program; if not, write to the Free Software\n"
        "Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.\n"
    ,
    .decoder.plugin.website = "http://deadbeef.sf.net",
    .decoder.open = aac_open,
    .decoder.init = aac_init,
    .decoder.free = aac_free,
    .decoder.read = aac_read,
    .decoder.seek = aac_seek,
    .decoder.seek_sample = aac_seek_sample,
    .decoder.insert = aac_insert,
    .decoder.read_metadata = mp4_read_metadata,
    .decoder.write_metadata = mp4_write_metadata,
    .decoder.exts = exts,
    .seek_sample64 = aac_seek_sample64,
};

DB_plugin_t *
aac_load (DB_functions_t *api) {
    deadbeef = api;
    return DB_PLUGIN (&plugin);
}
