[Flac-dev] flac_read callback not called in Windows?

[Scott Waye]

Hi,

Not sure if this should be in the dev or users list, but here goes.

I am using the FLAC seekable stream decoder in my MACH3 laser games emulation
in MAME (www.boldtower.com/mach3).  The game has a soundtrack (originally on
a laser disk) which I have flac encoded and play back in the game.  I did the
implementation under Linux which works fine, the callbacks are easy to set up
and I've had no problems.   I believe the code is OK because of this. 

I am now trying to get it to work under Windows 2000 with Msys and gcc 3.2. 
Everything compiles and links OK, but when it runs neither my flac_read, or
flac_write callback get called even though I call :

res = FLAC__seekable_stream_decoder_process_single(flacDecoder);

Has anyone else experienced this?  What follows is the code I am using, my
program just sits looping in the while block in the flac_update function:



// callback for the stream
// we need to get length words from the flac decode into the buffer
static void flac_update(int param, INT16 *buffer, int length)
{
	FLAC__bool res = true;

	fprintf(stderr, "start flac_update...");
	//TODO: check for playing? probably a better way to stop the sound
	if(laserdisc_playing)
	{
		while(length && res)
		{
			// need to decode some more data
			if(!decoded_samples)
			{
//				fprintf(stderr, "start flac_seekable_decoder_process...");
				/*fprintf(stderr, "stat %d should be %d\n ",
FLAC__seekable_stream_decoder_get_state(flacDecoder),
						FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC);
						*/
				res = FLAC__seekable_stream_decoder_process_single(flacDecoder);
//				fprintf(stderr, "end flac_seekable_decoder_process\n");
			}

			while(decoded_samples && length)
			{
				*buffer++ = decoded_flac_channel[decode_buffer_pos++];
				length--;
				decoded_samples--;
			}
		}
	}
	else
	{
		/* clear the sound ? */
		memset(buffer, 0, length << 1);
	}
	fprintf(stderr, "end flac_update\n");
}

static FLAC__SeekableStreamDecoderReadStatus flac_read(const
FLAC__SeekableStreamDecoder *decoder,
	FLAC__byte buffer[], unsigned *bytes, void *client_data)
{
	fprintf(stderr, "flac_read start ...");
	*bytes = mame_fread(flacFile, buffer, *bytes);
	fprintf(stderr, "flac_read end %d\n ", *bytes);
	return FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_OK;
}

static FLAC__SeekableStreamDecoderSeekStatus flac_seek(const
FLAC__SeekableStreamDecoder *decoder,
	FLAC__uint64 absolute_byte_offset, void *client_data)
{
	mame_fseek(flacFile, absolute_byte_offset, SEEK_SET);
	return FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK;
}

static FLAC__SeekableStreamDecoderTellStatus flac_tell(const
FLAC__SeekableStreamDecoder *decoder,
	FLAC__uint64 *absolute_byte_offset, void *client_data)
{
	*absolute_byte_offset = mame_ftell(flacFile);
	return FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK;
}

static FLAC__SeekableStreamDecoderLengthStatus flac_length(const
FLAC__SeekableStreamDecoder *decoder,
	FLAC__uint64 *stream_length, void *client_data)
{
	*stream_length = mame_fsize(flacFile);
	return FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_OK;
}

static FLAC__bool flac_eof(const FLAC__SeekableStreamDecoder *decoder, void
*client_data)
{
	return(osd_feof(flacFile)); 
}

static FLAC__StreamDecoderWriteStatus flac_write(const
FLAC__SeekableStreamDecoder *decoder, 
	const FLAC__Frame *frame, const FLAC__int32  * const buffer[], void
*client_data)
{
	decode_flac_frame = frame;
	decoded_flac_channel = buffer[0];
	decoded_samples = frame->header.blocksize;
	decode_buffer_pos = 0;
	fprintf(stderr, "flac_write %d\n", decoded_samples);
	return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE; // or ABORT
}

static void flac_metadata(const FLAC__SeekableStreamDecoder *decoder, 
	const FLAC__StreamMetadata *metadata, void *client_data)
{
	
}

static void flac_error(const FLAC__SeekableStreamDecoder *decoder, 
	FLAC__StreamDecoderErrorStatus status, void *client_data)
{
	fprintf(stderr, "flac_error %d\n", status);
	logerror("flac decode error %d\n", status);
}

static void init_flac(void)
{
	fprintf(stderr, "init flac\n");
	sprintf(flacFilename, "%s.flac", Machine->gamedrv->name);
	flacFile = mame_fopen(Machine->gamedrv->name, flacFilename,
FILETYPE_LASERDISK_FLAC, 0);
	if(flacFile)
	{
		flacDecoder = FLAC__seekable_stream_decoder_new();
		fprintf(stderr, "got decoder\n");
		if(!FLAC__seekable_stream_decoder_set_read_callback(flacDecoder,
flac_read))			fprintf(stderr, "Could not set flac read cb\n");
		if(!FLAC__seekable_stream_decoder_set_seek_callback(flacDecoder,
flac_seek))
			fprintf(stderr, "Could not set flac seek cb\n");
		if(!FLAC__seekable_stream_decoder_set_tell_callback(flacDecoder,
flac_tell))
			fprintf(stderr, "Could not set flac tell cb\n");
		if(!FLAC__seekable_stream_decoder_set_length_callback(flacDecoder,
flac_length))
			fprintf(stderr, "Could not set flac length cb\n");
		fprintf(stderr, "set length decoder\n");
		if(!FLAC__seekable_stream_decoder_set_eof_callback(flacDecoder, flac_eof))
			fprintf(stderr, "Could not set flac eof cb\n");
		if(!FLAC__seekable_stream_decoder_set_write_callback(flacDecoder,
flac_write))
			fprintf(stderr, "Could not set flac write cb\n");
		if(!FLAC__seekable_stream_decoder_set_metadata_callback(flacDecoder,
flac_metadata))
			fprintf(stderr, "Could not set metadata cb\n");
		if(!FLAC__seekable_stream_decoder_set_error_callback(flacDecoder,
flac_error))
			fprintf(stderr, "Could not set flac error cb\n");
		fprintf(stderr, "set error decoder\n");
		if(FLAC__seekable_stream_decoder_init(flacDecoder) !=
FLAC__SEEKABLE_STREAM_DECODER_OK)
		{
			fprintf(stderr, "flac init failed\n");
			logerror("flac init failed\n");
		}
	}
	else
	{
		fprintf(stderr, "flac file %s not found\n", flacFilename);
	}
}