claunia/flac
1
0
Fork 0
mirror of https://github.com/claunia/flac.git synced 2025-12-16 18:54:26 +00:00
Code Issues Packages Projects Releases Wiki Activity

fixes for new seeking algorithm

Browse Source
This commit is contained in:
Josh Coalson
2006-11-08 17:07:58 +00:00
parent 1d42ba6423
commit 8295fd03b6
1 changed files with 33 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

64
src/libFLAC/stream_decoder.c
View File

@@ -2928,17 +2928,23 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
FLAC__int64 pos = -1;
int i;
unsigned approx_bytes_per_frame;
FLAC__bool needs_seek = true, first_seek = true;
FLAC__bool first_seek = true;
const FLAC__uint64 total_samples = FLAC__stream_decoder_get_total_samples(decoder);
const unsigned min_blocksize = decoder->private_->stream_info.data.stream_info.min_blocksize;
const unsigned max_blocksize = decoder->private_->stream_info.data.stream_info.max_blocksize;
const unsigned max_framesize = decoder->private_->stream_info.data.stream_info.max_framesize;
const unsigned min_framesize = decoder->private_->stream_info.data.stream_info.min_framesize;
/* take these from the current frame in case they've changed mid-stream */
const unsigned channels = FLAC__stream_decoder_get_channels(decoder);
const unsigned bps = FLAC__stream_decoder_get_bits_per_sample(decoder);
unsigned channels = FLAC__stream_decoder_get_channels(decoder);
unsigned bps = FLAC__stream_decoder_get_bits_per_sample(decoder);
const FLAC__StreamMetadata_SeekTable *seek_table = decoder->private_->has_seek_table? &decoder->private_->seek_table.data.seek_table : 0;
/* use values from stream info if we didn't decode a frame */
if(channels == 0)
channels = decoder->private_->stream_info.data.stream_info.channels;
if(bps == 0)
bps = decoder->private_->stream_info.data.stream_info.bits_per_sample;
/* we are just guessing here */
if(max_framesize > 0)
approx_bytes_per_frame = (max_framesize + min_framesize) / 2 + 1;
@@ -2966,6 +2972,8 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
lower_bound_sample = 0;
upper_bound = stream_length;
upper_bound_sample = total_samples > 0 ? total_samples : target_sample;
if(upper_bound_sample == 0)
upper_bound_sample = 1;
/*
* Now we refine the bounds if we have a seektable with
@@ -3001,33 +3009,31 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
return false;
}
if(needs_seek) {
#ifndef FLAC__INTEGER_ONLY_LIBRARY
#if defined _MSC_VER || defined __MINGW32__
/* with VC++ you have to spoon feed it the casting */
pos = (FLAC__int64)lower_bound + (FLAC__int64)((FLAC__double)(FLAC__int64)(target_sample - lower_bound_sample) / (FLAC__double)(FLAC__int64)(upper_bound_sample - lower_bound_sample) * (FLAC__double)(FLAC__int64)(upper_bound - lower_bound)) - approx_bytes_per_frame;
/* with VC++ you have to spoon feed it the casting */
pos = (FLAC__int64)lower_bound + (FLAC__int64)((FLAC__double)(FLAC__int64)(target_sample - lower_bound_sample) / (FLAC__double)(FLAC__int64)(upper_bound_sample - lower_bound_sample) * (FLAC__double)(FLAC__int64)(upper_bound - lower_bound)) - approx_bytes_per_frame;
#else
pos = (FLAC__int64)lower_bound + (FLAC__int64)((FLAC__double)(target_sample - lower_bound_sample) / (FLAC__double)(upper_bound_sample - lower_bound_sample) * (FLAC__double)(upper_bound - lower_bound)) - approx_bytes_per_frame;
pos = (FLAC__int64)lower_bound + (FLAC__int64)((FLAC__double)(target_sample - lower_bound_sample) / (FLAC__double)(upper_bound_sample - lower_bound_sample) * (FLAC__double)(upper_bound - lower_bound)) - approx_bytes_per_frame;
#endif
#else
/* a little less accurate: */
if (upper_bound - lower_bound < 0xffffffff)
pos = (FLAC__int64)lower_bound + (FLAC__int64)(((target_sample - lower_bound_sample) * (upper_bound - lower_bound)) / (upper_bound_sample - lower_bound_sample)) - approx_bytes_per_frame;
else /* @@@ WATCHOUT, ~2TB limit */
pos = (FLAC__int64)lower_bound + (FLAC__int64)((((target_sample - lower_bound_sample)>>8) * ((upper_bound - lower_bound)>>8)) / ((upper_bound_sample - lower_bound_sample)>>16)) - approx_bytes_per_frame;
/* a little less accurate: */
if(upper_bound - lower_bound < 0xffffffff)
pos = (FLAC__int64)lower_bound + (FLAC__int64)(((target_sample - lower_bound_sample) * (upper_bound - lower_bound)) / (upper_bound_sample - lower_bound_sample)) - approx_bytes_per_frame;
else /* @@@ WATCHOUT, ~2TB limit */
pos = (FLAC__int64)lower_bound + (FLAC__int64)((((target_sample - lower_bound_sample)>>8) * ((upper_bound - lower_bound)>>8)) / ((upper_bound_sample - lower_bound_sample)>>16)) - approx_bytes_per_frame;
#endif
if(pos >= (FLAC__int64)upper_bound)
pos = (FLAC__int64)upper_bound - 1;
if(pos < (FLAC__int64)lower_bound)
pos = (FLAC__int64)lower_bound;
if(decoder->private_->seek_callback(decoder, (FLAC__uint64)pos, decoder->private_->client_data) != FLAC__STREAM_DECODER_SEEK_STATUS_OK) {
decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
return false;
}
if(!FLAC__stream_decoder_flush(decoder)) {
/* above call sets the state for us */
return false;
}
if(pos >= (FLAC__int64)upper_bound)
pos = (FLAC__int64)upper_bound - 1;
if(pos < (FLAC__int64)lower_bound)
pos = (FLAC__int64)lower_bound;
if(decoder->private_->seek_callback(decoder, (FLAC__uint64)pos, decoder->private_->client_data) != FLAC__STREAM_DECODER_SEEK_STATUS_OK) {
decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
return false;
}
if(!FLAC__stream_decoder_flush(decoder)) {
/* above call sets the state for us */
return false;
}
/* Now we need to get a frame. First we need to reset our
* unparseable_frame_count; if we get too many unparseable
@@ -3053,7 +3059,7 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
this_frame_sample = decoder->private_->last_frame.header.number.sample_number;
if (!decoder->private_->samples_decoded || (this_frame_sample + decoder->private_->last_frame.header.blocksize >= upper_bound_sample && !first_seek)) {
if (pos == (FLAC__int64)lower_bound || !needs_seek) {
if (pos == (FLAC__int64)lower_bound) {
decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
return false;
}
@@ -3072,8 +3078,6 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
approx_bytes_per_frame = decoder->private_->last_frame.header.blocksize * channels * bps/8 + 64;
/* we need to narrow the search */
if(target_sample < this_frame_sample) {
upper_bound_sample = this_frame_sample + decoder->private_->last_frame.header.blocksize;
@@ -3081,19 +3085,17 @@ FLAC__bool seek_to_absolute_sample_(FLAC__StreamDecoder *decoder, FLAC__uint64 s
decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
return false;
}
approx_bytes_per_frame = 2 * (upper_bound - pos) / 3 + 16;
}
else {
/* target_sample >= this_frame_sample + this frame's blocksize */
/* we are close, continue in decoding next frames */
if(target_sample < this_frame_sample + 4 * decoder->private_->last_frame.header.blocksize)
needs_seek = false;
lower_bound_sample = this_frame_sample + decoder->private_->last_frame.header.blocksize;
if(!FLAC__stream_decoder_get_decode_position(decoder, &lower_bound)) {
decoder->protected_->state = FLAC__STREAM_DECODER_SEEK_ERROR;
return false;
}
approx_bytes_per_frame = 2 * (lower_bound - pos) / 3 + 16;
}
}