Method copy_buffer

src/main/java/mp3/BitStream.java:899–995

copy data out of the internal MP3 bit buffer into a user supplied unsigned char buffer. mp3data=0 indicates data in buffer is an id3tags and VBR tags mp3data=1 data is real mp3 frame data.

(final LameInternalFlags gfc,
			final byte[] buffer, final int bufferPos, final int size,
			final int mp3data)

	 * </PRE>
	 */
	public final int copy_buffer(final LameInternalFlags gfc,
			final byte[] buffer, final int bufferPos, final int size,
			final int mp3data) {
		final int minimum = bufByteIdx + 1;
		if (minimum <= 0)
			return 0;
		if (size != 0 && minimum > size) {
			/* buffer is too small */
			return -1;
		}
		System.arraycopy(buf, 0, buffer, bufferPos, minimum);
		bufByteIdx = -1;
		bufBitIdx = 0;

		if (mp3data != 0) {
			int[] crc = new int[1];
			crc[0] = gfc.nMusicCRC;
			vbr.updateMusicCRC(crc, buffer, bufferPos, minimum);
			gfc.nMusicCRC = crc[0];

			/**
			 * sum number of bytes belonging to the mp3 stream this info will be
			 * written into the Xing/LAME header for seeking
			 */
			if (minimum > 0) {
				gfc.VBR_seek_table.nBytesWritten += minimum;
			}

			if (gfc.decode_on_the_fly) { /* decode the frame */
				float pcm_buf[][] = new float[2][1152];
				int mp3_in = minimum;
				int samples_out = -1;
				int i;

				/* re-synthesis to pcm. Repeat until we get a samples_out=0 */
				while (samples_out != 0) {

					samples_out = mpg.hip_decode1_unclipped(gfc.hip, buffer,
							bufferPos, mp3_in, pcm_buf[0], pcm_buf[1]);
					/*
					 * samples_out = 0: need more data to decode samples_out =
					 * -1: error. Lets assume 0 pcm output samples_out = number
					 * of samples output
					 */

					/*
					 * set the lenght of the mp3 input buffer to zero, so that
					 * in the next iteration of the loop we will be querying
					 * mpglib about buffered data
					 */
					mp3_in = 0;

					if (samples_out == -1) {
						/*
						 * error decoding. Not fatal, but might screw up the
						 * ReplayGain tag. What should we do? Ignore for now
						 */
						samples_out = 0;