Method DecodeNextFrame

src/decoder/plugins/MadDecoderPlugin.cxx:348–390

}

MadDecoderAction
MadDecoder::DecodeNextFrame(bool skip, Tag *tag) noexcept
{
	if ((stream.buffer == nullptr || stream.error == MAD_ERROR_BUFLEN) &&
	    !FillBuffer())
		return MadDecoderAction::BREAK;

	if (mad_header_decode(&frame.header, &stream)) {
		if (stream.error == MAD_ERROR_BUFLEN)
			return MadDecoderAction::CONT;

		if (stream.error == MAD_ERROR_LOSTSYNC && stream.this_frame) {
			signed long tagsize = id3_tag_query(stream.this_frame,
							    stream.bufend -
							    stream.this_frame);

			if (tagsize > 0) {
				ParseId3((size_t)tagsize, tag);
				return MadDecoderAction::CONT;
			}
		}

		return RecoverFrameError(stream);
	}

	enum mad_layer new_layer = frame.header.layer;
	if (layer == (mad_layer)0) {
		if (new_layer != MAD_LAYER_II && new_layer != MAD_LAYER_III) {
			/* Only layer 2 and 3 have been tested to work */
			return MadDecoderAction::SKIP;
		}

		layer = new_layer;
	} else if (new_layer != layer) {
		/* Don't decode frames with a different layer than the first */
		return MadDecoderAction::SKIP;
	}

	if (!skip && mad_frame_decode(&frame, &stream))
		return RecoverFrameError(stream);

	return MadDecoderAction::OK;
}

/* xing stuff stolen from alsaplayer, and heavily modified by jat */
static constexpr unsigned XI_MAGIC = (('X' << 8) | 'i');