C++ DB_decoder_t::seek_sample方法代码示例

// prepare to decode the track, fill in mandatory plugin fields
// return -1 on failure
static int
example_init (DB_fileinfo_t *_info, DB_playItem_t *it) {
    example_info_t *info = (example_info_t *)_info;

    // take this parameters from your input file
    // we set constants for clarity sake
    _info->fmt.bps = 16;
    _info->fmt.channels = 2;
    _info->fmt.samplerate  = 44100;
    for (int i = 0; i < _info->fmt.channels; i++) {
        _info->fmt.channelmask |= 1 << i;
    }
    _info->readpos = 0;
    _info->plugin = &plugin;

    if (it->endsample > 0) {
        info->startsample = it->startsample;
        info->endsample = it->endsample;
        plugin.seek_sample (_info, 0);
    }
    else {
        info->startsample = 0;
        int TOTALSAMPLES = 1000; // calculate from file
        info->endsample = TOTALSAMPLES-1;
    }
    return 0;
}

static int
tta_init (DB_fileinfo_t *_info, DB_playItem_t *it) {
    tta_info_t *info = (tta_info_t *)_info;

    deadbeef->pl_lock ();
    const char *fname = deadbeef->pl_find_meta (it, ":URI")
    trace ("open_tta_file %s\n", fname);
    if (open_tta_file (fname, &info->tta, 0) != 0) {
        deadbeef->pl_unlock ();
        fprintf (stderr, "tta: failed to open %s\n", fname);
        return -1;
    }

    if (player_init (&info->tta) != 0) {
        deadbeef->pl_unlock ();
        fprintf (stderr, "tta: failed to init player for %s\n", fname);
        return -1;
    }
    deadbeef->pl_unlock ();

    _info->fmt.bps = info->tta.BPS;
    _info->fmt.channels = info->tta.NCH;
    _info->fmt.samplerate = info->tta.SAMPLERATE;
    for (int i = 0; i < _info->fmt.channels; i++) {
        _info->fmt.channelmask |= 1 << i;
    }
    _info->readpos = 0;
    _info->plugin = &plugin;

    int64_t endsample = deadbeef->pl_item_get_endsample (it);
    if (endsample > 0) {
        info->startsample = deadbeef->pl_item_get_startsample (it);
        info->endsample = endsample;
        plugin.seek_sample (_info, 0);
    }
    else {
        info->startsample = 0;
        info->endsample = (info->tta.DATALENGTH)-1;
    }
    trace ("open_tta_file %s success!\n", deadbeef->pl_find_meta (it, ":URI"));
    return 0;
}

//.........这里部分代码省略.........
            if (offs == -1) {
                trace ("aac stream not found\n");
                return -1;
            }
            if (offs > info->junk) {
                info->junk = offs;
            }
            if (info->junk >= 0) {
                deadbeef->fseek (info->file, info->junk, SEEK_SET);
            }
            else {
                deadbeef->rewind (info->file);
            }
            trace ("found aac stream (junk: %d, offs: %d)\n", info->junk, offs);
        }

        _info->fmt.channels = channels;
        _info->fmt.samplerate = samplerate;
    }
    else {
        // sync before attempting to init
        int samplerate, channels;
        float duration;
        int offs = parse_aac_stream (info->file, &samplerate, &channels, &duration, NULL);
        if (offs < 0) {
            trace ("aac: parse_aac_stream failed\n");
            return -1;
        }
        if (offs > info->junk) {
            info->junk = offs;
        }
        trace("parse_aac_stream returned %x\n", offs);
        deadbeef->pl_replace_meta (it, "!FILETYPE", "AAC");
    }

//    duration = (float)totalsamples / samplerate;
//    deadbeef->pl_set_item_duration (it, duration);

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

    if (!info->mp4file) {
        //trace ("NeAACDecGetCapabilities\n");
        //unsigned long caps = NeAACDecGetCapabilities();

        trace ("NeAACDecOpen\n");
        info->dec = NeAACDecOpen ();

        trace ("prepare for NeAACDecInit: fread %d from offs %lld\n", AAC_BUFFER_SIZE, deadbeef->ftell (info->file));
        info->remaining = deadbeef->fread (info->buffer, 1, AAC_BUFFER_SIZE, info->file);

        NeAACDecConfigurationPtr conf = NeAACDecGetCurrentConfiguration (info->dec);
//        conf->dontUpSampleImplicitSBR = 1;
        NeAACDecSetConfiguration (info->dec, conf);
        unsigned long srate;
        unsigned char ch;
        trace ("NeAACDecInit (%d bytes)\n", info->remaining);
        int consumed = NeAACDecInit (info->dec, info->buffer, info->remaining, &srate, &ch);
        trace ("NeAACDecInit returned samplerate=%d, channels=%d, consumed: %d\n", (int)srate, (int)ch, consumed);
        if (consumed < 0) {
            trace ("NeAACDecInit returned %d\n", consumed);
            return -1;
        }
        if (consumed > info->remaining) {
            trace ("NeAACDecInit consumed more than available! wtf?\n");
            return -1;
        }
        if (consumed == info->remaining) {
            info->remaining = 0;
        }
        else if (consumed > 0) {
            memmove (info->buffer, info->buffer + consumed, info->remaining - consumed);
            info->remaining -= consumed;
        }
        _info->fmt.channels = ch;
        _info->fmt.samplerate = srate;
    }

    if (!info->file->vfs->is_streaming ()) {
        if (it->endsample > 0) {
            info->startsample = it->startsample;
            info->endsample = it->endsample;
            plugin.seek_sample (_info, 0);
        }
        else {
            info->startsample = 0;
            info->endsample = totalsamples-1;
        }
    }
    trace ("totalsamples: %d, endsample: %d, samples-from-duration: %d\n", totalsamples-1, info->endsample, (int)deadbeef->pl_get_item_duration (it)*44100);

    for (int i = 0; i < _info->fmt.channels; i++) {
        _info->fmt.channelmask |= 1 << i;
    }
    info->noremap = 0;
    info->remap[0] = -1;
    trace ("init success\n");

    return 0;
}

static int
wv_init (DB_fileinfo_t *_info, DB_playItem_t *it) {
    wvctx_t *info = (wvctx_t *)_info;
    deadbeef->pl_lock ();
    info->file = deadbeef->fopen (deadbeef->pl_find_meta (it, ":URI"));
    deadbeef->pl_unlock ();
    if (!info->file) {
        return -1;
    }

#ifndef TINYWV
    deadbeef->pl_lock ();
    const char *uri = deadbeef->pl_find_meta (it, ":URI");
    char *c_fname = alloca (strlen (uri) + 2);
    if (c_fname) {
        strcpy (c_fname, uri);
        strcat (c_fname, "c");
        info->c_file = deadbeef->fopen (c_fname);
    }
    else {
        fprintf (stderr, "wavpack warning: failed to alloc memory for correction file name\n");
    }
    deadbeef->pl_unlock ();
#endif

    char error[80];
#ifdef TINYWV
    info->ctx = WavpackOpenFileInput (wv_read_stream, info->file, error);
#else
    info->ctx = WavpackOpenFileInputEx (&wsr, info->file, info->c_file, error, OPEN_NORMALIZE, 0);
#endif
    if (!info->ctx) {
        fprintf (stderr, "wavpack error: %s\n", error);
        return -1;
    }
    _info->plugin = &plugin;
    _info->fmt.bps = WavpackGetBytesPerSample (info->ctx) * 8;
    _info->fmt.channels = WavpackGetNumChannels (info->ctx);
    _info->fmt.samplerate = WavpackGetSampleRate (info->ctx);
    _info->fmt.is_float = (WavpackGetMode (info->ctx) & MODE_FLOAT) ? 1 : 0;

    // FIXME: streamer and maybe output plugins need to be fixed to support
    // arbitrary channelmask

    // _info->fmt.channelmask = WavpackGetChannelMask (info->ctx);

    for (int i = 0; i < _info->fmt.channels; i++) {
        _info->fmt.channelmask |= 1 << i;
    }
    _info->readpos = 0;
    if (it->endsample > 0) {
        info->startsample = it->startsample;
        info->endsample = it->endsample;
        if (plugin.seek_sample (_info, 0) < 0) {
            return -1;
        }
    }
    else {
        info->startsample = 0;
        info->endsample = WavpackGetNumSamples (info->ctx)-1;
    }
    return 0;
}

//.........这里部分代码省略.........
                trace ("aac stream not found\n");
                return -1;
            }
            if (offs > info->junk) {
                info->junk = offs;
            }
            if (info->junk >= 0) {
                deadbeef->fseek (info->file, info->junk, SEEK_SET);
            }
            else {
                deadbeef->rewind (info->file);
            }
            trace ("found aac stream (junk: %d, offs: %d)\n", info->junk, offs);

            _info->fmt.channels = channels;
            _info->fmt.samplerate = samplerate;
        }
    }
    else {
        // sync before attempting to init
        int samplerate, channels;
        float duration;
        int offs = parse_aac_stream (info->file, &samplerate, &channels, &duration, NULL);
        if (offs < 0) {
            trace ("aac: parse_aac_stream failed\n");
            return -1;
        }
        if (offs > info->junk) {
            info->junk = offs;
        }
        trace("parse_aac_stream returned %x\n", offs);
        deadbeef->pl_replace_meta (it, "!FILETYPE", "AAC");
    }

//    duration = (float)totalsamples / samplerate;
//    deadbeef->pl_set_item_duration (it, duration);

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

    if (!info->mp4) {
        trace ("NeAACDecOpen for raw stream\n");
        info->dec = NeAACDecOpen ();

        trace ("prepare for NeAACDecInit: fread %d from offs %lld\n", AAC_BUFFER_SIZE, deadbeef->ftell (info->file));
        info->remaining = deadbeef->fread (info->buffer, 1, AAC_BUFFER_SIZE, info->file);

        NeAACDecConfigurationPtr conf = NeAACDecGetCurrentConfiguration (info->dec);
//        conf->dontUpSampleImplicitSBR = 1;
        NeAACDecSetConfiguration (info->dec, conf);
        unsigned long srate;
        unsigned char ch;
        trace ("NeAACDecInit (%d bytes)\n", info->remaining);
        int consumed = NeAACDecInit (info->dec, info->buffer, info->remaining, &srate, &ch);
        trace ("NeAACDecInit returned samplerate=%d, channels=%d, consumed: %d\n", (int)srate, (int)ch, consumed);
        if (consumed < 0) {
            trace ("NeAACDecInit returned %d\n", consumed);
            return -1;
        }
        if (consumed > info->remaining) {
            trace ("NeAACDecInit consumed more than available! wtf?\n");
            return -1;
        }
        if (consumed == info->remaining) {
            info->remaining = 0;
        }
        else if (consumed > 0) {
            memmove (info->buffer, info->buffer + consumed, info->remaining - consumed);
            info->remaining -= consumed;
        }
        _info->fmt.channels = ch;
        _info->fmt.samplerate = srate;
    }

    if (!info->file->vfs->is_streaming ()) {
        if (it->endsample > 0) {
            info->startsample = it->startsample;
            info->endsample = it->endsample;
            plugin.seek_sample (_info, 0);
        }
        else {
            info->startsample = 0;
            info->endsample = totalsamples-1;
        }
    }
    if (_info->fmt.channels == 7) {
        _info->fmt.channels = 8;
    }

    trace ("totalsamples: %d, endsample: %d, samples-from-duration: %d, samplerate %d, channels %d\n", totalsamples-1, 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;
    info->remap[0] = -1;
    trace ("init success\n");

    return 0;
}

static int
sndfile_init (DB_fileinfo_t *_info, DB_playItem_t *it) {
    sndfile_info_t *info = (sndfile_info_t*)_info;

    SF_INFO inf;
    DB_FILE *fp = deadbeef->fopen (deadbeef->pl_find_meta (it, ":URI"));
    if (!fp) {
        trace ("sndfile: failed to open %s\n", deadbeef->pl_find_meta (it, ":URI"));
        return -1;
    }
    int fsize = deadbeef->fgetlength (fp);

    info->file = fp;
    info->ctx = sf_open_virtual (&vfs, SFM_READ, &inf, info);
    if (!info->ctx) {
        trace ("sndfile: %s: unsupported file format\n");
        return -1;
    }
    _info->plugin = &plugin;
    info->sf_format = inf.format&0x000f;

    switch (inf.format&0x000f) {
    case SF_FORMAT_PCM_S8:
    case SF_FORMAT_PCM_U8:
        _info->fmt.bps = 8;
        break;
    case SF_FORMAT_PCM_16:
        _info->fmt.bps = 16;
        break;
    case SF_FORMAT_PCM_24:
        _info->fmt.bps = 24;
        break;
    case SF_FORMAT_FLOAT:
        _info->fmt.is_float = 1;
    case SF_FORMAT_PCM_32:
        _info->fmt.bps = 32;
        break;
    default:
        info->read_as_short = 1;
        _info->fmt.bps = 16;
        trace ("[sndfile] unidentified input format: 0x%X\n", inf.format&0x000f);
        break;
    }

    _info->fmt.channels = inf.channels;
    _info->fmt.samplerate = inf.samplerate;

    int channel_map [inf.channels];
    int cmdres = sf_command (info->ctx, SFC_GET_CHANNEL_MAP_INFO, channel_map, sizeof (channel_map)) ;
    if (cmdres != SF_FALSE) {
        // channel map found, convert to channel mask
        _info->fmt.channelmask = wavex_gen_channel_mask (channel_map, inf.channels);
    }
    else {
        // channel map not found, generate from channel number
        for (int i = 0; i < inf.channels; i++) {
            _info->fmt.channelmask |= 1 << i;
        }
    }

    _info->readpos = 0;
    if (it->endsample > 0) {
        info->startsample = it->startsample;
        info->endsample = it->endsample;
        if (plugin.seek_sample (_info, 0) < 0) {
            return -1;
        }
    }
    else {
        info->startsample = 0;
        info->endsample = inf.frames-1;
    }
    // hack bitrate

    int totalsamples = inf.frames;
    float sec = (float)totalsamples / inf.samplerate;
    if (sec > 0) {
        info->bitrate = fsize / sec * 8 / 1000;
    }
    else {
        info->bitrate = -1;
    }

    return 0;
}