vgmstream/src/coding/at3plus_decoder.c

#include "coding.h"
#include "../util.h"

#ifdef VGM_USE_MAIATRAC3PLUS
#include "maiatrac3plus.h"

struct maiatrac3plus_codec_data {
    sample_t* buffer;
    int channels;
    int samples_discard;
    void* handle;
};


maiatrac3plus_codec_data *init_at3plus() {

    maiatrac3plus_codec_data *data = malloc(sizeof(maiatrac3plus_codec_data));
    data->buffer = 0;
    data->samples_discard = 0;
    data->handle = Atrac3plusDecoder_openContext();
    if (!data->handle) goto fail;

    return data;

fail:
    return NULL;
}

void decode_at3plus(VGMSTREAM * vgmstream, sample * outbuf, int channelspacing, int32_t samples_to_do, int channel) {
    VGMSTREAMCHANNEL *ch = &vgmstream->ch[0];
    maiatrac3plus_codec_data *data = vgmstream->codec_data;
    int i;

	int first_sample = vgmstream->samples_into_block % 2048;

	if (0 == channel && (0 == first_sample || data->samples_discard == first_sample))
    {
        uint8_t code_buffer[0x8000];
		int blocks_to_decode = 1;
		int max_blocks_to_decode = (ch->offset - ch->channel_start_offset) / vgmstream->interleave_block_size + 1;
		if (data->samples_discard) blocks_to_decode = 8;
		if (blocks_to_decode > max_blocks_to_decode) blocks_to_decode = max_blocks_to_decode;
		while (blocks_to_decode--) {
			ch->streamfile->read(ch->streamfile, code_buffer, ch->offset - blocks_to_decode * vgmstream->interleave_block_size, vgmstream->interleave_block_size);
			Atrac3plusDecoder_decodeFrame(data->handle, code_buffer, vgmstream->interleave_block_size, &data->channels, (void**)&data->buffer);
		}
		data->samples_discard = 0;
    }

    for (i = 0; i < samples_to_do; i++) {
        outbuf[i*channelspacing] = data->buffer[(first_sample+i)*data->channels+channel];
    }

	if (0 == channel && 2048 == first_sample + samples_to_do) {
		ch->offset += vgmstream->interleave_block_size;
	}
}


void reset_at3plus(VGMSTREAM *vgmstream) {
    maiatrac3plus_codec_data *data = vgmstream->codec_data;
    if (!data) return;

    if (data->handle)
        Atrac3plusDecoder_closeContext(data->handle);
    data->handle = Atrac3plusDecoder_openContext();
    data->samples_discard = 0;
}

void seek_at3plus(VGMSTREAM *vgmstream, int32_t num_sample) {
    int blocks_to_skip = num_sample / 2048;
    int samples_to_discard = num_sample % 2048;
    maiatrac3plus_codec_data *data = (maiatrac3plus_codec_data *)(vgmstream->codec_data);
    if (!data) return;

    vgmstream->loop_ch[0].offset =
        vgmstream->loop_ch[0].channel_start_offset +
        vgmstream->interleave_block_size * blocks_to_skip;
    data->samples_discard = samples_to_discard;
}

void free_at3plus(maiatrac3plus_codec_data *data) {
    if (data) {
        if (data->handle) Atrac3plusDecoder_closeContext(data->handle);
        free(data);
    }
}

#endif