/* this is the codec entry point */
enum codec_status codec_start(struct codec_api* api)
{
struct codec_api* ci = api;
FLAC__SeekableStreamDecoder* flacDecoder;
FLAC__uint64 offset;
TEST_CODEC_API(ci);
#ifndef SIMULATOR
ci->memcpy(iramstart, iramcopy, iramend-iramstart);
#endif
ci->configure(CODEC_SET_FILEBUF_LIMIT, (int *)(1024*1024*10));
ci->configure(CODEC_SET_FILEBUF_WATERMARK, (int *)(1024*512));
ci->configure(CODEC_SET_FILEBUF_CHUNKSIZE, (int *)(1024*1024));
ci->configure(CODEC_DSP_ENABLE, (bool *)true);
ci->configure(DSP_DITHER, (bool *)false);
ci->configure(DSP_SET_STEREO_MODE, (int *)STEREO_INTERLEAVED);
ci->configure(DSP_SET_SAMPLE_DEPTH, (int *)(16));
next_track:
metadata_length = 0;
seek_table = NULL;
stream_info = NULL;
if (codec_init(api)) {
return CODEC_ERROR;
}
while (!ci->taginfo_ready)
ci->yield();
ci->configure(DSP_SET_FREQUENCY, (long *)(ci->id3->frequency));
codec_set_replaygain(ci->id3);
/* Create a decoder instance */
flacDecoder = FLAC__seekable_stream_decoder_new();
/* Set up the decoder and the callback functions - this must be done before init */
/* The following are required for stream_decoder and higher */
FLAC__seekable_stream_decoder_set_client_data(flacDecoder,ci);
FLAC__seekable_stream_decoder_set_write_callback(flacDecoder, flac_write_handler);
FLAC__seekable_stream_decoder_set_read_callback(flacDecoder, flac_read_handler);
FLAC__seekable_stream_decoder_set_metadata_callback(flacDecoder, flac_metadata_handler);
FLAC__seekable_stream_decoder_set_error_callback(flacDecoder, flac_error_handler);
FLAC__seekable_stream_decoder_set_metadata_respond_all(flacDecoder);
/* The following are only for the seekable_stream_decoder */
FLAC__seekable_stream_decoder_set_seek_callback(flacDecoder, flac_seek_handler);
FLAC__seekable_stream_decoder_set_tell_callback(flacDecoder, flac_tell_handler);
FLAC__seekable_stream_decoder_set_length_callback(flacDecoder, flac_length_handler);
FLAC__seekable_stream_decoder_set_eof_callback(flacDecoder, flac_eof_handler);
/* QUESTION: What do we do when the init fails? */
if (FLAC__seekable_stream_decoder_init(flacDecoder)) {
return CODEC_ERROR;
}
/* The first thing to do is to parse the metadata */
FLAC__seekable_stream_decoder_process_until_end_of_metadata(flacDecoder);
if (ci->id3->offset && stream_info) {
FLAC__uint64 sample;
sample = find_sample_number(ci, ci->id3->offset - metadata_length);
ci->advance_buffer(ci->id3->offset);
FLAC__seekable_stream_decoder_seek_absolute(flacDecoder, sample);
FLAC__seekable_stream_decoder_get_decode_position(flacDecoder, &offset);
ci->set_offset(offset);
samplesdone = (uint32_t)sample;
ci->set_elapsed(sample/(ci->id3->frequency/1000));
} else {
samplesdone = 0;
ci->set_elapsed(0);
}
/* The main decoder loop */
while (FLAC__seekable_stream_decoder_get_state(flacDecoder) != FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM) {
ci->yield();
if (ci->stop_codec || ci->reload_codec) {
break;
}
if (ci->seek_time) {
int sample_loc;
sample_loc = ci->seek_time/1000 * ci->id3->frequency;
if (FLAC__seekable_stream_decoder_seek_absolute(flacDecoder, sample_loc)) {
samplesdone = sample_loc;
ci->set_elapsed(samplesdone/(ci->id3->frequency/1000));
}
ci->seek_time = 0;
}
FLAC__seekable_stream_decoder_process_single(flacDecoder);
FLAC__seekable_stream_decoder_get_decode_position(flacDecoder, &offset);
ci->set_offset(offset);
}
/* Flush the libFLAC buffers */
FLAC__seekable_stream_decoder_finish(flacDecoder);
if (ci->request_next_track()) {
if (stream_info) {
FLAC__metadata_object_delete(stream_info);
}
if (seek_table) {
FLAC__metadata_object_delete(seek_table);
}
metadata_length = 0;
goto next_track;
}
return CODEC_OK;
}
FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 stream_length, FLAC__uint64 target_sample)
{
FLAC__uint64 first_frame_offset, lower_bound, upper_bound;
FLAC__int64 pos = -1, last_pos = -1;
int i, lower_seek_point = -1, upper_seek_point = -1;
unsigned approx_bytes_per_frame;
FLAC__uint64 last_frame_sample = FLAC__U64L(0xffffffffffffffff);
FLAC__bool needs_seek;
const FLAC__uint64 total_samples = decoder->private_->stream_info.total_samples;
const unsigned min_blocksize = decoder->private_->stream_info.min_blocksize;
const unsigned max_blocksize = decoder->private_->stream_info.max_blocksize;
const unsigned max_framesize = decoder->private_->stream_info.max_framesize;
const unsigned channels = FLAC__seekable_stream_decoder_get_channels(decoder);
const unsigned bps = FLAC__seekable_stream_decoder_get_bits_per_sample(decoder);
/* we are just guessing here, but we want to guess high, not low */
if(max_framesize > 0) {
approx_bytes_per_frame = max_framesize;
}
/*
* Check if it's a known fixed-blocksize stream. Note that though
* the spec doesn't allow zeroes in the STREAMINFO block, we may
* never get a STREAMINFO block when decoding so the value of
* min_blocksize might be zero.
*/
else if(min_blocksize == max_blocksize && min_blocksize > 0) {
/* note there are no () around 'bps/8' to keep precision up since it's an integer calulation */
approx_bytes_per_frame = min_blocksize * channels * bps/8 + 64;
}
else
approx_bytes_per_frame = 4608 * channels * bps/8 + 64;
/*
* The decode position is currently at the first frame since we
* rewound and processed metadata.
*/
if(!FLAC__seekable_stream_decoder_get_decode_position(decoder, &first_frame_offset)) {
decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
return false;
}
/*
* First, we set an upper and lower bound on where in the
* stream we will search. For now we assume the worst case
* scenario, which is our best guess at the beginning of
* the first and last frames.
*/
lower_bound = first_frame_offset;
/* calc the upper_bound, beyond which we never want to seek */
if(max_framesize > 0)
upper_bound = stream_length - (max_framesize + 128 + 2); /* 128 for a possible ID3V1 tag, 2 for indexing differences */
else
upper_bound = stream_length - ((channels * bps * FLAC__MAX_BLOCK_SIZE) / 8 + 128 + 2);
/*
* Now we refine the bounds if we have a seektable with
* suitable points. Note that according to the spec they
* must be ordered by ascending sample number.
*/
if(0 != decoder->private_->seek_table) {
/* find the closest seek point <= target_sample, if it exists */
for(i = (int)decoder->private_->seek_table->num_points - 1; i >= 0; i--) {
if(decoder->private_->seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER && decoder->private_->seek_table->points[i].sample_number <= target_sample)
break;
}
if(i >= 0) { /* i.e. we found a suitable seek point... */
lower_bound = first_frame_offset + decoder->private_->seek_table->points[i].stream_offset;
lower_seek_point = i;
}
/* find the closest seek point > target_sample, if it exists */
for(i = 0; i < (int)decoder->private_->seek_table->num_points; i++) {
if(decoder->private_->seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER && decoder->private_->seek_table->points[i].sample_number > target_sample)
break;
}
if(i < (int)decoder->private_->seek_table->num_points) { /* i.e. we found a suitable seek point... */
upper_bound = first_frame_offset + decoder->private_->seek_table->points[i].stream_offset;
upper_seek_point = i;
}
}
/*
* Now guess at where within those bounds our target
* sample will be.
*/
if(lower_seek_point >= 0) {
/* first see if our sample is within a few frames of the lower seekpoint */
if(decoder->private_->seek_table->points[lower_seek_point].sample_number <= target_sample && target_sample < decoder->private_->seek_table->points[lower_seek_point].sample_number + (decoder->private_->seek_table->points[lower_seek_point].frame_samples * 4)) {
pos = (FLAC__int64)lower_bound;
}
else if(upper_seek_point >= 0) {
const FLAC__uint64 target_offset = target_sample - decoder->private_->seek_table->points[lower_seek_point].sample_number;
const FLAC__uint64 range_samples = decoder->private_->seek_table->points[upper_seek_point].sample_number - decoder->private_->seek_table->points[lower_seek_point].sample_number;
const FLAC__uint64 range_bytes = upper_bound - lower_bound;
#if defined _MSC_VER || defined __MINGW32__
/* with VC++ you have to spoon feed it the casting */
pos = (FLAC__int64)lower_bound + (FLAC__int64)((double)(FLAC__int64)target_offset / (double)(FLAC__int64)range_samples * (double)(FLAC__int64)(range_bytes-1)) - approx_bytes_per_frame;
#else
pos = (FLAC__int64)lower_bound + (FLAC__int64)((double)target_offset / (double)range_samples * (double)(range_bytes-1)) - approx_bytes_per_frame;
#endif
}
}
/*
* If there's no seek table, we need to use the metadata (if we
* have it) and the filelength to estimate the position of the
* frame with the correct sample.
*/
if(pos < 0 && total_samples > 0) {
#if defined _MSC_VER || defined __MINGW32__
/* with VC++ you have to spoon feed it the casting */
pos = (FLAC__int64)first_frame_offset + (FLAC__int64)((double)(FLAC__int64)target_sample / (double)(FLAC__int64)total_samples * (double)(FLAC__int64)(stream_length-first_frame_offset-1)) - approx_bytes_per_frame;
#else
pos = (FLAC__int64)first_frame_offset + (FLAC__int64)((double)target_sample / (double)total_samples * (double)(stream_length-first_frame_offset-1)) - approx_bytes_per_frame;
#endif
}
/*
* If there's no seek table and total_samples is unknown, we
* don't even bother trying to figure out a target, we just use
* our current position.
*/
if(pos < 0) {
FLAC__uint64 upos;
if(decoder->private_->tell_callback(decoder, &upos, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK) {
decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
return false;
}
pos = (FLAC__int64)upos;
needs_seek = false;
}
else
needs_seek = true;
/* clip the position to the bounds, lower bound takes precedence */
if(pos >= (FLAC__int64)upper_bound) {
pos = (FLAC__int64)upper_bound-1;
needs_seek = true;
}
if(pos < (FLAC__int64)lower_bound) {
pos = (FLAC__int64)lower_bound;
needs_seek = true;
}
decoder->private_->target_sample = target_sample;
while(1) {
if(needs_seek) {
if(decoder->private_->seek_callback(decoder, (FLAC__uint64)pos, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK) {
decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
return false;
}
if(!FLAC__stream_decoder_flush(decoder->private_->stream_decoder)) {
decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_DECODER_ERROR;
return false;
}
}
/* Now we need to get a frame. It is possible for our seek
* to land in the middle of audio data that looks exactly like
* a frame header from a future version of an encoder. When
* that happens, FLAC__stream_decoder_process_single() will
* return false and the state will be
* FLAC__STREAM_DECODER_UNPARSEABLE_STREAM. But there is a
* remote possibility that it is properly synced at such a
* "future-codec frame", so to make sure, we wait to see
* several "unparseable" errors in a row before bailing out.
*/
{
unsigned unparseable_count;
FLAC__bool got_a_frame = false;
for (unparseable_count = 0; !got_a_frame && unparseable_count < 10; unparseable_count++) {
if(FLAC__stream_decoder_process_single(decoder->private_->stream_decoder))
got_a_frame = true;
else if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_UNPARSEABLE_STREAM)
/* try again. we don't want to flush the decoder since that clears the bitbuffer */
decoder->private_->stream_decoder->protected_->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
else /* it's a real error */
break;
}
if (!got_a_frame) {
decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
return false;
}
}
/* our write callback will change the state when it gets to the target frame */
if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING) {
break;
}
else { /* we need to narrow the search */
const FLAC__uint64 this_frame_sample = decoder->private_->last_frame.header.number.sample_number;
FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
if(this_frame_sample == last_frame_sample && pos < last_pos) {
/* our last move backwards wasn't big enough, double it */
pos -= (last_pos - pos);
needs_seek = true;
}
else {
if(target_sample < this_frame_sample) {
last_pos = pos;
approx_bytes_per_frame = decoder->private_->last_frame.header.blocksize * channels * bps/8 + 64;
pos -= approx_bytes_per_frame;
needs_seek = true;
}
else { /* target_sample >= this_frame_sample + this frame's blocksize */
FLAC__uint64 upos;
if(decoder->private_->tell_callback(decoder, &upos, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK) {
decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
return false;
}
last_pos = pos;
pos = (FLAC__int64)upos;
pos -= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder);
needs_seek = false;
/*
* if we haven't hit the target frame yet and our position hasn't changed,
* it means we're at the end of the stream and the seek target does not exist.
*/
if(last_pos == pos) {
decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
return false;
}
}
}
if(pos < (FLAC__int64)lower_bound)
pos = (FLAC__int64)lower_bound;
last_frame_sample = this_frame_sample;
}
}
return true;
}
FLAC_API FLAC__bool FLAC__file_decoder_get_decode_position(const FLAC__FileDecoder *decoder, FLAC__uint64 *position)
{
FLAC__ASSERT(0 != decoder);
FLAC__ASSERT(0 != decoder->private_);
return FLAC__seekable_stream_decoder_get_decode_position(decoder->private_->seekable_stream_decoder, position);
}
