seekable_stream_decoder.c

wince下著名的视频播放器源码

/* libFLAC - Free Lossless Audio Codec library
 * Copyright (C) 2000,2001,2002,2003,2004,2005  Josh Coalson
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h> /* for calloc() */
#include <string.h> /* for memcpy()/memcmp() */
#include "FLAC/assert.h"
#include "protected/seekable_stream_decoder.h"
#include "protected/stream_decoder.h"
#include "private/float.h" /* for FLAC__double */
#include "private/md5.h"

/* adjust for compilers that can't understand using LLU suffix for uint64_t literals */
#ifdef _MSC_VER
#define FLAC__U64L(x) x
#else
#define FLAC__U64L(x) x##LLU
#endif

/***********************************************************************
 *
 * Private class method prototypes
 *
 ***********************************************************************/

static void set_defaults_(FLAC__SeekableStreamDecoder *decoder);
static FLAC__StreamDecoderReadStatus read_callback_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data);
static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
static FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 stream_length, FLAC__uint64 target_sample);

/***********************************************************************
 *
 * Private class data
 *
 ***********************************************************************/

typedef struct FLAC__SeekableStreamDecoderPrivate {
	FLAC__SeekableStreamDecoderReadCallback read_callback;
	FLAC__SeekableStreamDecoderSeekCallback seek_callback;
	FLAC__SeekableStreamDecoderTellCallback tell_callback;
	FLAC__SeekableStreamDecoderLengthCallback length_callback;
	FLAC__SeekableStreamDecoderEofCallback eof_callback;
	FLAC__SeekableStreamDecoderWriteCallback write_callback;
	FLAC__SeekableStreamDecoderMetadataCallback metadata_callback;
	FLAC__SeekableStreamDecoderErrorCallback error_callback;
	void *client_data;
	FLAC__StreamDecoder *stream_decoder;
	FLAC__bool do_md5_checking; /* initially gets protected_->md5_checking but is turned off after a seek */
	struct FLAC__MD5Context md5context;
	FLAC__byte stored_md5sum[16]; /* this is what is stored in the metadata */
	FLAC__byte computed_md5sum[16]; /* this is the sum we computed from the decoded data */
	/* the rest of these are only used for seeking: */
	FLAC__StreamMetadata_StreamInfo stream_info; /* we keep this around so we can figure out how to seek quickly */
	const FLAC__StreamMetadata_SeekTable *seek_table; /* we hold a pointer to the stream decoder's seek table for the same reason */
	/* Since we always want to see the STREAMINFO and SEEK_TABLE blocks at this level, we need some extra flags to keep track of whether they should be passed on up through the metadata_callback */
	FLAC__bool ignore_stream_info_block;
	FLAC__bool ignore_seek_table_block;
	FLAC__Frame last_frame; /* holds the info of the last frame we seeked to */
	FLAC__uint64 target_sample;
} FLAC__SeekableStreamDecoderPrivate;

/***********************************************************************
 *
 * Public static class data
 *
 ***********************************************************************/

FLAC_API const char * const FLAC__SeekableStreamDecoderStateString[] = {
	"FLAC__SEEKABLE_STREAM_DECODER_OK",
	"FLAC__SEEKABLE_STREAM_DECODER_SEEKING",
	"FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM",
	"FLAC__SEEKABLE_STREAM_DECODER_MEMORY_ALLOCATION_ERROR",
	"FLAC__SEEKABLE_STREAM_DECODER_STREAM_DECODER_ERROR",
	"FLAC__SEEKABLE_STREAM_DECODER_READ_ERROR",
	"FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR",
	"FLAC__SEEKABLE_STREAM_DECODER_ALREADY_INITIALIZED",
	"FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK",
	"FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED"
};

FLAC_API const char * const FLAC__SeekableStreamDecoderReadStatusString[] = {
	"FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_OK",
	"FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_ERROR"
};

FLAC_API const char * const FLAC__SeekableStreamDecoderSeekStatusString[] = {
	"FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK",
	"FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_ERROR"
};

FLAC_API const char * const FLAC__SeekableStreamDecoderTellStatusString[] = {
	"FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK",
	"FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_ERROR"
};

FLAC_API const char * const FLAC__SeekableStreamDecoderLengthStatusString[] = {
	"FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_OK",
	"FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_ERROR"
};


/***********************************************************************
 *
 * Class constructor/destructor
 *
 ***********************************************************************/

FLAC_API FLAC__SeekableStreamDecoder *FLAC__seekable_stream_decoder_new()
{
	FLAC__SeekableStreamDecoder *decoder;

	FLAC__ASSERT(sizeof(int) >= 4); /* we want to die right away if this is not true */

	decoder = (FLAC__SeekableStreamDecoder*)calloc(1, sizeof(FLAC__SeekableStreamDecoder));
	if(decoder == 0) {
		return 0;
	}

	decoder->protected_ = (FLAC__SeekableStreamDecoderProtected*)calloc(1, sizeof(FLAC__SeekableStreamDecoderProtected));
	if(decoder->protected_ == 0) {
		free(decoder);
		return 0;
	}

	decoder->private_ = (FLAC__SeekableStreamDecoderPrivate*)calloc(1, sizeof(FLAC__SeekableStreamDecoderPrivate));
	if(decoder->private_ == 0) {
		free(decoder->protected_);
		free(decoder);
		return 0;
	}

	decoder->private_->stream_decoder = FLAC__stream_decoder_new();
	if(0 == decoder->private_->stream_decoder) {
		free(decoder->private_);
		free(decoder->protected_);
		free(decoder);
		return 0;
	}

	set_defaults_(decoder);

	decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED;

	return decoder;
}

FLAC_API void FLAC__seekable_stream_decoder_delete(FLAC__SeekableStreamDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->protected_);
	FLAC__ASSERT(0 != decoder->private_);
	FLAC__ASSERT(0 != decoder->private_->stream_decoder);

	(void)FLAC__seekable_stream_decoder_finish(decoder);

	FLAC__stream_decoder_delete(decoder->private_->stream_decoder);

	free(decoder->private_);
	free(decoder->protected_);
	free(decoder);
}

/***********************************************************************
 *
 * Public class methods
 *
 ***********************************************************************/

FLAC_API FLAC__SeekableStreamDecoderState FLAC__seekable_stream_decoder_init(FLAC__SeekableStreamDecoder *decoder)
{
	FLAC__ASSERT(0 != decoder);

	if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
		return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_ALREADY_INITIALIZED;

	if(0 == decoder->private_->read_callback || 0 == decoder->private_->seek_callback || 0 == decoder->private_->tell_callback || 0 == decoder->private_->length_callback || 0 == decoder->private_->eof_callback)
		return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK;

	if(0 == decoder->private_->write_callback || 0 == decoder->private_->metadata_callback || 0 == decoder->private_->error_callback)
		return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK;

	decoder->private_->seek_table = 0;

	decoder->private_->do_md5_checking = decoder->protected_->md5_checking;

	/* We initialize the FLAC__MD5Context even though we may never use it.  This
	 * is because md5 checking may be turned on to start and then turned off if
	 * a seek occurs.  So we always init the context here and finalize it in
	 * FLAC__seekable_stream_decoder_finish() to make sure things are always
	 * cleaned up properly.
	 */
	FLAC__MD5Init(&decoder->private_->md5context);

	FLAC__stream_decoder_set_read_callback(decoder->private_->stream_decoder, read_callback_);
	FLAC__stream_decoder_set_write_callback(decoder->private_->stream_decoder, write_callback_);
	FLAC__stream_decoder_set_metadata_callback(decoder->private_->stream_decoder, metadata_callback_);
	FLAC__stream_decoder_set_error_callback(decoder->private_->stream_decoder, error_callback_);
	FLAC__stream_decoder_set_client_data(decoder->private_->stream_decoder, decoder);

	/* We always want to see these blocks.  Whether or not we pass them up
	 * through the metadata callback will be determined by flags set in our
	 * implementation of ..._set_metadata_respond/ignore...()
	 */
	FLAC__stream_decoder_set_metadata_respond(decoder->private_->stream_decoder, FLAC__METADATA_TYPE_STREAMINFO);
	FLAC__stream_decoder_set_metadata_respond(decoder->private_->stream_decoder, FLAC__METADATA_TYPE_SEEKTABLE);

	if(FLAC__stream_decoder_init(decoder->private_->stream_decoder) != FLAC__STREAM_DECODER_SEARCH_FOR_METADATA)
		return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_DECODER_ERROR;

	return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_OK;
}

FLAC_API FLAC__bool FLAC__seekable_stream_decoder_finish(FLAC__SeekableStreamDecoder *decoder)
{
	FLAC__bool md5_failed = false;

	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->private_);
	FLAC__ASSERT(0 != decoder->protected_);

	if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
		return true;

	FLAC__ASSERT(0 != decoder->private_->stream_decoder);

	/* see the comment in FLAC__seekable_stream_decoder_init() as to why we
	 * always call FLAC__MD5Final()
	 */
	FLAC__MD5Final(decoder->private_->computed_md5sum, &decoder->private_->md5context);

	FLAC__stream_decoder_finish(decoder->private_->stream_decoder);

	if(decoder->private_->do_md5_checking) {
		if(memcmp(decoder->private_->stored_md5sum, decoder->private_->computed_md5sum, 16))
			md5_failed = true;
	}

	set_defaults_(decoder);

	decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED;

	return !md5_failed;
}

FLAC_API FLAC__bool FLAC__seekable_stream_decoder_set_md5_checking(FLAC__SeekableStreamDecoder *decoder, FLAC__bool value)
{
	FLAC__ASSERT(0 != decoder);
	FLAC__ASSERT(0 != decoder->protected_);