mpd/src/inputPlugins/mpc_plugin.c

/* the Music Player Daemon (MPD)
 * (c)2003-2005 by Warren Dukes (shank@mercury.chem.pitt.edu)
 * This project's homepage is: http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "../inputPlugin.h"

#ifdef HAVE_MUSEPACK

#include "../utils.h"
#include "../audio.h"
#include "../log.h"
#include "../pcm_utils.h"
#include "../inputStream.h"
#include "../outputBuffer.h"
#include "../replayGain.h"

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <musepack/musepack.h>
#include <errno.h>

typedef struct _MpcCallbackData {
        InputStream * inStream;
        DecoderControl * dc;
} MpcCallbackData;

mpc_int32_t mpc_read_cb(void * vdata, void * ptr, mpc_int32_t size) {
	mpc_int32_t ret = 0;
        MpcCallbackData * data = (MpcCallbackData *)vdata;

        while(1) {
	        ret = readFromInputStream(data->inStream, ptr, 1, size);
                if(ret == 0 && !inputStreamAtEOF(data->inStream) && 
                                !data->dc->stop) 
                {
                        my_usleep(10000);
                }
                else break;
        }

	return ret;
}

static mpc_bool_t mpc_seek_cb(void * vdata, mpc_int32_t offset) {
        MpcCallbackData * data = (MpcCallbackData *)vdata;

	return seekInputStream(data->inStream , offset, SEEK_SET) < 0 ? 0 : 1;
}

mpc_int32_t mpc_tell_cb(void * vdata) {
        MpcCallbackData * data = (MpcCallbackData *)vdata;

	return (long)(data->inStream->offset);
}

mpc_bool_t mpc_canseek_cb(void * vdata) {
        MpcCallbackData * data = (MpcCallbackData *)vdata;

	return data->inStream->seekable;
}

mpc_int32_t mpc_getsize_cb(void * vdata) {
        MpcCallbackData * data = (MpcCallbackData *)vdata;

	return data->inStream->size;
}

inline mpd_sint16 convertSample(MPC_SAMPLE_FORMAT sample) {
	/* only doing 16-bit audio for now */
	mpd_sint32 val;

        const int clip_min = -1 << (16 - 1);
        const int clip_max = (1 << (16 - 1)) - 1;
	
#ifdef MPC_FIXED_POINT
	const int shift = 16 - MPC_FIXED_POINT_SCALE_SHIFT;

	if( ssample > 0 ) {
		sample <<= shift;
	}
	else if ( shift < 0 ) {
		sample >>= -shift;
	}
	val = sample;
#else
	const int float_scale = 1 << (16 - 1);

	val = sample * float_scale;
#endif

	if( val < clip_min) val = clip_min;
	else if ( val > clip_max ) val = clip_max;

	return val;
}

int mpc_decode(OutputBuffer * cb, DecoderControl * dc, InputStream * inStream)
{
	mpc_decoder decoder;
	mpc_reader reader;
	mpc_streaminfo info;

	MpcCallbackData data;

	MPC_SAMPLE_FORMAT sample_buffer[MPC_DECODER_BUFFER_LENGTH];

	int eof = 0;
	long ret;
#define MPC_CHUNK_SIZE 4096
	char chunk[MPC_CHUNK_SIZE];
	int chunkpos = 0;
	long bitRate = 0;
	mpd_sint16 * s16 = (mpd_sint16 *) chunk;
	unsigned long samplePos = 0;
	mpc_uint32_t vbrUpdateAcc;
	mpc_uint32_t vbrUpdateBits;
	float time;
	int i;
	ReplayGainInfo * replayGainInfo = NULL;

        data.inStream = inStream;
        data.dc = dc;

	reader.read = mpc_read_cb;
	reader.seek = mpc_seek_cb;
	reader.tell = mpc_tell_cb;
	reader.get_size = mpc_getsize_cb;
	reader.canseek = mpc_canseek_cb;
	reader.data = &data;

	mpc_streaminfo_init(&info);
	
	if((ret = mpc_streaminfo_read(&info, &reader)) != ERROR_CODE_OK) {
		closeInputStream(inStream);
		if(!dc->stop) {
		        ERROR("Not a valid musepack stream");
			return -1;
                }
                else {
                        dc->state = DECODE_STATE_STOP;
                        dc->stop = 0;
                }
                return 0;
	}

	mpc_decoder_setup(&decoder, &reader);

	if(!mpc_decoder_initialize(&decoder, &info)) {
		closeInputStream(inStream);
		if(!dc->stop) {
		        ERROR("Not a valid musepack stream");
                }
                else {
                        dc->state = DECODE_STATE_STOP;
                        dc->stop = 0;
                }
	}
	
	dc->totalTime = mpc_streaminfo_get_length(&info);

	dc->audioFormat.bits = 16;
	dc->audioFormat.channels = info.channels;
	dc->audioFormat.sampleRate = info.sample_freq;
	
	getOutputAudioFormat(&(dc->audioFormat), &(cb->audioFormat));

	replayGainInfo = newReplayGainInfo();
	replayGainInfo->albumGain = info.gain_album;
	replayGainInfo->albumPeak = info.peak_album;
	replayGainInfo->trackGain = info.gain_title;
	replayGainInfo->trackPeak = info.peak_title;

	dc->state = DECODE_STATE_DECODE;

	while(!eof) {
		if(dc->seek) {
			samplePos = dc->seekWhere * dc->audioFormat.sampleRate;
			if(mpc_decoder_seek_sample(&decoder, samplePos)) {
                                clearOutputBuffer(cb);
			        chunkpos = 0;
                        }
                        else dc->seekError = 1;
			dc->seek = 0;
		}

		ret = mpc_decoder_decode(&decoder, sample_buffer,
				         &vbrUpdateAcc, &vbrUpdateBits);

		if(ret <= 0 || dc->stop ) {
			eof = 1;
			break;
		}

		samplePos += ret;

		/* ret is in samples, and we have stereo */
		ret *= 2;

		for(i = 0; i < ret; i++) {
			/* 16 bit audio again */
			*s16 = convertSample(sample_buffer[i]);
			chunkpos += 2;
			s16++;

		       	if(chunkpos >= MPC_CHUNK_SIZE) {
                                time = ((float)samplePos) /
				       dc->audioFormat.sampleRate;

				bitRate = vbrUpdateBits * 
					  dc->audioFormat.sampleRate / 
					  (MPC_CHUNK_SIZE);
				
				sendDataToOutputBuffer(cb, inStream, dc, 
						inStream->seekable,  
                                        	chunk, chunkpos, 
						time,
						bitRate,
						replayGainInfo);

				chunkpos = 0;
				s16 = (mpd_sint16 *)chunk;
				if(dc->stop) {
					eof = 1;
					break;
				}
			}
		}
	}

	if(!dc->stop && chunkpos > 0) {
                time = ((float)samplePos) / dc->audioFormat.sampleRate;

		bitRate = vbrUpdateBits * dc->audioFormat.sampleRate /
			  chunkpos;

		sendDataToOutputBuffer(cb, NULL, dc, inStream->seekable,
				       chunk, chunkpos, time, bitRate, 
				       replayGainInfo);
	}

	closeInputStream(inStream);

	flushOutputBuffer(cb);

	freeReplayGainInfo(replayGainInfo);

	if(dc->stop) {
		dc->state = DECODE_STATE_STOP;
		dc->stop = 0;
	}
	else {
		dc->state = DECODE_STATE_STOP;
	}

	return 0;
}

MpdTag * mpcTagDup(char * file) {
	MpdTag * ret = NULL;
	FILE * fp;

	fp = fopen(file,"r"); 
	if(!fp) return NULL;

	/* get tag info here */

	if(!ret) ret = newMpdTag();
	ret->time = 0;

	return ret;	
}

char * mpcSuffixes[] = {"mpc", NULL};
char * mpcMimeTypes[] = {NULL};

InputPlugin mpcPlugin =
{
        "mpc",
	NULL,
	NULL,
        mpc_decode,
        NULL,
        mpcTagDup,
        INPUT_PLUGIN_STREAM_URL | INPUT_PLUGIN_STREAM_FILE,
        mpcSuffixes,
        mpcMimeTypes
};

#else

InputPlugin mpcPlugin = 
{
	NULL,
	NULL,
	NULL,
        NULL,
        NULL,
        NULL,
        0,
        NULL,
        NULL
};

#endif