From f40bfc9267b13b54e6379dfe7539447662879d24 Mon Sep 17 00:00:00 2001 From: Sean Bartell Date: Sat, 25 Jun 2011 21:32:25 -0400 Subject: Add codecs to librbcodec. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97 Reviewed-on: http://gerrit.rockbox.org/137 Reviewed-by: Nils Wallménius Tested-by: Nils Wallménius --- lib/rbcodec/codecs/libgme/blip_buffer.c | 225 ++++++++++++++++++++++++++++++++ 1 file changed, 225 insertions(+) create mode 100644 lib/rbcodec/codecs/libgme/blip_buffer.c (limited to 'lib/rbcodec/codecs/libgme/blip_buffer.c') diff --git a/lib/rbcodec/codecs/libgme/blip_buffer.c b/lib/rbcodec/codecs/libgme/blip_buffer.c new file mode 100644 index 0000000000..ba0a6558d2 --- /dev/null +++ b/lib/rbcodec/codecs/libgme/blip_buffer.c @@ -0,0 +1,225 @@ +// Blip_Buffer 0.4.1. http://www.slack.net/~ant/ + +#include "blip_buffer.h" + +#include +#include +#include +#include + +/* Copyright (C) 2003-2006 Shay Green. This module is free software; you +can redistribute it and/or modify it under the terms of the GNU Lesser +General Public License as published by the Free Software Foundation; either +version 2.1 of the License, or (at your option) any later version. This +module 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 Lesser General Public License for more +details. You should have received a copy of the GNU Lesser General Public +License along with this module; if not, write to the Free Software Foundation, +Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ + +#include "blargg_source.h" + +void Blip_init( struct Blip_Buffer* this ) +{ + this->factor_ = UINT_MAX/2 + 1;; + this->buffer_center_ = NULL; + this->buffer_size_ = 0; + this->sample_rate_ = 0; + this->bass_shift_ = 0; + this->clock_rate_ = 0; + this->bass_freq_ = 16; + this->length_ = 0; + + // assumptions code makes about implementation-defined features + #ifndef NDEBUG + // right shift of negative value preserves sign + buf_t_ i = -0x7FFFFFFE; + assert( (i >> 1) == -0x3FFFFFFF ); + + // casting to short truncates to 16 bits and sign-extends + i = 0x18000; + assert( (short) i == -0x8000 ); + #endif + + Blip_clear( this ); +} + +void Blip_clear( struct Blip_Buffer* this ) +{ + bool const entire_buffer = true; + + this->offset_ = 0; + this->reader_accum_ = 0; + this->modified = false; + + if ( this->buffer_ ) + { + int count = (entire_buffer ? this->buffer_size_ : Blip_samples_avail( this )); + memset( this->buffer_, 0, (count + blip_buffer_extra_) * sizeof (delta_t) ); + } +} + +blargg_err_t Blip_set_sample_rate( struct Blip_Buffer* this, int new_rate, int msec ) +{ + // Limit to maximum size that resampled time can represent + int max_size = (((blip_resampled_time_t) -1) >> BLIP_BUFFER_ACCURACY) - + blip_buffer_extra_ - 64; // TODO: -64 isn't needed + int new_size = (new_rate * (msec + 1) + 999) / 1000; + if ( new_size > max_size ) + new_size = max_size; + + // Resize buffer + if ( this->buffer_size_ != new_size ) { + this->buffer_center_ = this->buffer_ + BLIP_MAX_QUALITY/2; + this->buffer_size_ = new_size; + } + + // update things based on the sample rate + this->sample_rate_ = new_rate; + this->length_ = new_size * 1000 / new_rate - 1; + if ( this->clock_rate_ ) + Blip_set_clock_rate( this, this->clock_rate_ ); + Blip_bass_freq( this, this->bass_freq_ ); + + Blip_clear( this ); + + return 0; // success +} + +blip_resampled_time_t Blip_clock_rate_factor( struct Blip_Buffer* this, int rate ) +{ + int factor = (int) ( this->sample_rate_ * (1LL << BLIP_BUFFER_ACCURACY) / rate); + assert( factor > 0 || !this->sample_rate_ ); // fails if clock/output ratio is too large + return (blip_resampled_time_t) factor; +} + +void Blip_bass_freq( struct Blip_Buffer* this, int freq ) +{ + this->bass_freq_ = freq; + int shift = 31; + if ( freq > 0 && this->sample_rate_ ) + { + shift = 13; + int f = (freq << 16) / this->sample_rate_; + while ( (f >>= 1) && --shift ) { } + } + this->bass_shift_ = shift; +} + +void Blip_end_frame( struct Blip_Buffer* this, blip_time_t t ) +{ + this->offset_ += t * this->factor_; + assert( Blip_samples_avail( this ) <= (int) this->buffer_size_ ); // time outside buffer length +} + +int Blip_count_samples( struct Blip_Buffer* this, blip_time_t t ) +{ + blip_resampled_time_t last_sample = Blip_resampled_time( this, t ) >> BLIP_BUFFER_ACCURACY; + blip_resampled_time_t first_sample = this->offset_ >> BLIP_BUFFER_ACCURACY; + return (int) (last_sample - first_sample); +} + +blip_time_t Blip_count_clocks( struct Blip_Buffer* this, int count ) +{ + if ( count > this->buffer_size_ ) + count = this->buffer_size_; + blip_resampled_time_t time = (blip_resampled_time_t) count << BLIP_BUFFER_ACCURACY; + return (blip_time_t) ((time - this->offset_ + this->factor_ - 1) / this->factor_); +} + +void Blip_remove_samples( struct Blip_Buffer* this, int count ) +{ + if ( count ) + { + Blip_remove_silence( this, count ); + + // copy remaining samples to beginning and clear old samples + int remain = Blip_samples_avail( this ) + blip_buffer_extra_; + memmove( this->buffer_, this->buffer_ + count, remain * sizeof *this->buffer_ ); + memset( this->buffer_ + remain, 0, count * sizeof *this->buffer_ ); + } +} + +int Blip_read_samples( struct Blip_Buffer* this, blip_sample_t out_ [], int max_samples, bool stereo ) +{ + int count = Blip_samples_avail( this ); + if ( count > max_samples ) + count = max_samples; + + if ( count ) + { + int const bass = this->bass_shift_; + delta_t const* reader = this->buffer_ + count; + int reader_sum = this->reader_accum_; + + blip_sample_t* BLARGG_RESTRICT out = out_ + count; + if ( stereo ) + out += count; + int offset = -count; + + if ( !stereo ) + { + do + { + int s = reader_sum >> delta_bits; + + reader_sum -= reader_sum >> bass; + reader_sum += reader [offset]; + + BLIP_CLAMP( s, s ); + out [offset] = (blip_sample_t) s; + } + while ( ++offset ); + } + else + { + do + { + int s = reader_sum >> delta_bits; + + reader_sum -= reader_sum >> bass; + reader_sum += reader [offset]; + + BLIP_CLAMP( s, s ); + out [offset * 2] = (blip_sample_t) s; + } + while ( ++offset ); + } + + this->reader_accum_ = reader_sum; + + Blip_remove_samples( this, count ); + } + return count; +} + +void Blip_mix_samples( struct Blip_Buffer* this, blip_sample_t const in [], int count ) +{ + delta_t* out = this->buffer_center_ + (this->offset_ >> BLIP_BUFFER_ACCURACY); + + int const sample_shift = blip_sample_bits - 16; + int prev = 0; + while ( --count >= 0 ) + { + int s = *in++ << sample_shift; + *out += s - prev; + prev = s; + ++out; + } + *out -= prev; +} + +// Blip_Synth + +void volume_unit( struct Blip_Synth* this, int new_unit ) +{ + this->delta_factor = (int) (new_unit * (1LL << blip_sample_bits) / FP_ONE_VOLUME); +} + +void Synth_init( struct Blip_Synth* this ) +{ + this->buf = 0; + this->last_amp = 0; + this->delta_factor = 0; +} -- cgit v1.2.3