Function wavpack_decode

src/decoder/plugins/WavpackDecoderPlugin.cxx:170–230

* This does the main decoding thing. * Requires an already opened WavpackContext. */

 * Requires an already opened WavpackContext.
 */
static void
wavpack_decode(DecoderClient &client, WavpackContext *wpc, bool can_seek)
{
	const auto audio_format = CheckAudioFormat(wpc);

	auto *format_samples = format_samples_nop;
	if (audio_format.format == SampleFormat::DSD)
		format_samples = format_samples_int<uint8_t>;
	else if (audio_format.format != SampleFormat::FLOAT) {
		switch (WavpackGetBytesPerSample(wpc)) {
		case 1:
			format_samples = format_samples_int<int8_t>;
			break;

		case 2:
			format_samples = format_samples_int<int16_t>;
			break;
		}
	}

	client.Ready(audio_format, can_seek, GetDuration(wpc));

	const std::size_t output_frame_size = audio_format.GetFrameSize();

	/* wavpack gives us all kind of samples in a 32-bit space */
	int32_t buffer[1024];
	const uint32_t max_frames = std::size(buffer) / audio_format.channels;

	DecoderCommand cmd = client.GetCommand();
	while (cmd != DecoderCommand::STOP) {
		if (cmd == DecoderCommand::SEEK) {
			if (can_seek) {
				auto where = client.GetSeekFrame();
				if (!WavpackSeekSample64(wpc, where)) {
					/* seek errors are fatal */
					client.SeekError();
					break;
				}

				client.CommandFinished();
			} else {
				client.SeekError();
			}
		}

		uint32_t n_frames = WavpackUnpackSamples(wpc, buffer,
							 max_frames);
		if (n_frames == 0)
			break;

		int bitrate = lround(WavpackGetInstantBitrate(wpc) / 1000);
		format_samples(buffer, n_frames * audio_format.channels);

		cmd = client.SubmitAudio(nullptr,
					 {
						 (const std::byte *)buffer,
						 n_frames * output_frame_size,
					 },