/* in_flac - Winamp2 FLAC input plugin
* Copyright (C) 2000,2001,2002 Josh Coalson
*
+ * dithering routine derived from (other GPLed source):
+ * mad - MPEG audio decoder
+ * Copyright (C) 2000-2001 Robert Leslie
+ *
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
#include "in2.h"
#include "FLAC/all.h"
+
+#define MAX_SUPPORTED_CHANNELS 2
+
typedef struct {
FLAC__byte raw[128];
char title[31];
int decode_pos_ms_; /* current decoding position, in milliseconds */
int paused_; /* are we paused? */
int seek_needed_; /* if != -1, it is the point that the decode thread should seek to, in ms. */
-FLAC__int16 reservoir_[FLAC__MAX_BLOCK_SIZE * 2 * 2]; /* *2 for max channels, another *2 for overflow */
-char sample_buffer_[576 * 2 * (16/8) * 2]; /* 2 for max channels, (16/8) for max bytes per sample, and 2 for who knows what */
-unsigned samples_in_reservoir_;
+FLAC__int32 reservoir_[FLAC__MAX_BLOCK_SIZE * 2/*for overflow*/ * MAX_SUPPORTED_CHANNELS];
+char sample_buffer_[576 * MAX_SUPPORTED_CHANNELS * (24/8) * 2]; /* (24/8) for max bytes per sample, and 2 for who knows what */
+unsigned wide_samples_in_reservoir_;
static file_info_struct file_info_;
static FLAC__FileDecoder *decoder_;
DWORD WINAPI __stdcall DecodeThread(void *b); /* the decode thread procedure */
+
+/* 32-bit pseudo-random number generator */
+static inline FLAC__uint32 prng(FLAC__uint32 state)
+{
+ return (state * 0x0019660dL + 0x3c6ef35fL) & 0xffffffffL;
+}
+
+/* dither routine derived from MAD winamp plugin */
+
+typedef struct {
+ FLAC__int32 error[3];
+ FLAC__int32 random;
+} dither_state;
+
+static inline FLAC__int32 linear_dither(unsigned source_bps, unsigned target_bps, FLAC__int32 sample, dither_state *dither, const FLAC__int32 MIN, const FLAC__int32 MAX)
+{
+ unsigned scalebits;
+ FLAC__int32 output, mask, random;
+
+ FLAC__ASSERT(source_bps < 32);
+ FLAC__ASSERT(target_bps <= 24);
+ FLAC__ASSERT(target_bps <= source_bps);
+
+ /* noise shape */
+ sample += dither->error[0] - dither->error[1] + dither->error[2];
+
+ dither->error[2] = dither->error[1];
+ dither->error[1] = dither->error[0] / 2;
+
+ /* bias */
+ output = sample + (1L << (source_bps - target_bps - 1));
+
+ scalebits = source_bps - target_bps;
+ mask = (1L << scalebits) - 1;
+
+ /* dither */
+ random = (FLAC__int32)prng(dither->random);
+ output += (random & mask) - (dither->random & mask);
+
+ dither->random = random;
+
+ /* clip */
+ if(output > MAX) {
+ output = MAX;
+
+ if(sample > MAX)
+ sample = MAX;
+ }
+ else if(output < MIN) {
+ output = MIN;
+
+ if(sample < MIN)
+ sample = MIN;
+ }
+
+ /* quantize */
+ output &= ~mask;
+
+ /* error feedback */
+ dither->error[0] = sample - output;
+
+ /* scale */
+ return output >> scalebits;
+}
+
+static unsigned pack_pcm(FLAC__byte *data, FLAC__int32 *input, unsigned wide_samples, unsigned channels, unsigned source_bps, unsigned target_bps)
+{
+ static dither_state dither[MAX_SUPPORTED_CHANNELS];
+ FLAC__byte * const start = data;
+ FLAC__int32 sample;
+ const unsigned bytes_per_sample = target_bps / 8;
+ const unsigned samples = wide_samples * channels;
+
+ FLAC__ASSERT(MAX_SUPPORTED_CHANNELS == 2);
+ FLAC__ASSERT(channels > 0 && channels <= MAX_SUPPORTED_CHANNELS);
+ FLAC__ASSERT(source_bps < 32);
+ FLAC__ASSERT(target_bps <= 24);
+ FLAC__ASSERT(target_bps <= source_bps);
+ FLAC__ASSERT(source_bps & 7 == 0);
+ FLAC__ASSERT(target_bps & 7 == 0);
+
+ if(source_bps != target_bps) {
+ const FLAC__int32 MIN = source_bps == -(1L << source_bps);
+ const FLAC__int32 MAX = ~MIN; /*(1L << (source_bps-1)) - 1 */
+ const unsigned dither_twiggle = channels - 1;
+ unsigned dither_source = 0;
+
+ while(samples--) {
+ sample = linear_dither(source_bps, target_bps, *input++, &dither[dither_source], MIN, MAX);
+ dither_source ^= dither_twiggle;
+
+ switch(target_bps) {
+ case 8:
+ data[0] = sample ^ 0x80;
+ break;
+ case 24:
+ data[2] = sample >> 16;
+ /* fall through */
+ case 16:
+ data[1] = sample >> 8;
+ data[0] = sample >> 0;
+ }
+
+ data += bytes_per_sample;
+ }
+ }
+ else {
+ while(samples--) {
+ sample = *input++;
+
+ switch(target_bps) {
+ case 8:
+ data[0] = sample ^ 0x80;
+ break;
+ case 24:
+ data[2] = sample >> 16;
+ /* fall through */
+ case 16:
+ data[1] = sample >> 8;
+ data[0] = sample >> 0;
+ }
+
+ data += bytes_per_sample;
+ }
+ }
+
+ return data - start;
+}
+
+#if 0
+@@@@ incorporate this
+static void do_vis(char *data, int nch, int resolution, int position)
+{
+ static char vis_buffer[PCM_CHUNK * 2];
+ char *ptr;
+ int size, count;
+
+ /*
+ * Winamp visuals may have problems accepting sample sizes larger than
+ * 16 bits, so we reduce the sample size here if necessary.
+ */
+
+ switch(resolution) {
+ case 32:
+ case 24:
+ size = resolution / 8;
+ count = PCM_CHUNK * nch;
+
+ ptr = vis_buffer;
+ while(count--) {
+ data += size;
+ *ptr++ = data[-1] ^ 0x80;
+ }
+
+ data = vis_buffer;
+ resolution = 8;
+
+ /* fall through */
+ case 16:
+ case 8:
+ default:
+ module.SAAddPCMData(data, nch, resolution, position);
+ module.VSAAddPCMData(data, nch, resolution, position);
+ }
+}
+#endif
+
void config(HWND hwndParent)
{
MessageBox(hwndParent, "No configuration.", "Configuration", MB_OK);
paused_ = 0;
decode_pos_ms_ = 0;
seek_needed_ = -1;
- samples_in_reservoir_ = 0;
+ wide_samples_in_reservoir_ = 0;
maxlatency = mod_.outMod->Open(file_info_.sample_rate, file_info_.channels, file_info_.bits_per_sample, -1, -1);
- if (maxlatency < 0) { /* error opening device */
+ if(maxlatency < 0) { /* error opening device */
return 1;
}
void stop()
{
- if (thread_handle != INVALID_HANDLE_VALUE) {
+ if(thread_handle != INVALID_HANDLE_VALUE) {
killDecodeThread = 1;
- if (WaitForSingleObject(thread_handle, INFINITE) == WAIT_TIMEOUT) {
+ if(WaitForSingleObject(thread_handle, INFINITE) == WAIT_TIMEOUT) {
MessageBox(mod_.hMainWindow, "error asking thread to die!\n", "error killing decode thread", 0);
TerminateThread(thread_handle, 0);
}
if(0 == filename || filename[0] == '\0') {
filename = lastfn_;
- if (length_in_msec) {
+ if(length_in_msec) {
*length_in_msec = getlength();
length_in_msec = 0; /* force skip in following code */
}
{
int done = 0;
- while (! *((int *)b) ) {
+ while(! *((int *)b) ) {
unsigned channels = file_info_.channels;
unsigned bits_per_sample = file_info_.bits_per_sample;
unsigned bytes_per_sample = (bits_per_sample+7)/8;
unsigned sample_rate = file_info_.sample_rate;
- if (seek_needed_ != -1) {
+ if(seek_needed_ != -1) {
const double distance = (double)seek_needed_ / (double)getlength();
unsigned target_sample = (unsigned)(distance * (double)file_info_.total_samples);
if(FLAC__file_decoder_seek_absolute(decoder_, (FLAC__uint64)target_sample)) {
mod_.outMod->Flush(decode_pos_ms_);
}
}
- if (done) {
- if (!mod_.outMod->IsPlaying()) {
+ if(done) {
+ if(!mod_.outMod->IsPlaying()) {
PostMessage(mod_.hMainWindow, WM_WA_MPEG_EOF, 0, 0);
return 0;
}
Sleep(10);
}
- else if (mod_.outMod->CanWrite() >= ((int)(576*channels*bytes_per_sample) << (mod_.dsp_isactive()?1:0))) {
- while(samples_in_reservoir_ < 576) {
+ else if(mod_.outMod->CanWrite() >= ((int)(576*channels*bytes_per_sample) << (mod_.dsp_isactive()?1:0))) {
+ while(wide_samples_in_reservoir_ < 576) {
if(FLAC__file_decoder_get_state(decoder_) == FLAC__FILE_DECODER_END_OF_FILE) {
done = 1;
break;
}
}
- if (samples_in_reservoir_ == 0) {
+ if(wide_samples_in_reservoir_ == 0) {
done = 1;
}
else {
- unsigned i, n = min(samples_in_reservoir_, 576), delta;
- int bytes;
- signed short *ssbuffer = (signed short *)sample_buffer_;
-
- for(i = 0; i < n*channels; i++)
- ssbuffer[i] = reservoir_[i];
- delta = i;
- for( ; i < samples_in_reservoir_ * channels; i++)
+ const unsigned target_bps = 16;
+ const unsigned n = min(wide_samples_in_reservoir_, 576);
+ const unsigned delta = n * channels;
+ int bytes = (int)pack_pcm(sample_buffer_, reservoir_, n, channels, bits_per_sample, target_bps);
+ unsigned i;
+
+ for(i = delta; i < wide_samples_in_reservoir_ * channels; i++)
reservoir_[i-delta] = reservoir_[i];
- samples_in_reservoir_ -= n;
+ wide_samples_in_reservoir_ -= n;
- mod_.SAAddPCMData((char *)sample_buffer_, channels, bits_per_sample, decode_pos_ms_);
- mod_.VSAAddPCMData((char *)sample_buffer_, channels, bits_per_sample, decode_pos_ms_);
+ mod_.SAAddPCMData((char *)sample_buffer_, channels, target_bps, decode_pos_ms_);
+ mod_.VSAAddPCMData((char *)sample_buffer_, channels, target_bps, decode_pos_ms_);
decode_pos_ms_ += (n*1000 + sample_rate/2)/sample_rate;
- if (mod_.dsp_isactive())
- bytes = mod_.dsp_dosamples((short *)sample_buffer_, n, bits_per_sample, channels, sample_rate) * (channels*bytes_per_sample);
- else
- bytes = n * channels * bytes_per_sample;
+ if(mod_.dsp_isactive())
+ bytes = mod_.dsp_dosamples((short *)sample_buffer_, n, target_bps, channels, sample_rate) * (channels*target_bps/8);
mod_.outMod->Write(sample_buffer_, bytes);
}
}
{
file_info_struct *file_info_ = (file_info_struct *)client_data;
const unsigned bps = file_info_->bits_per_sample, channels = file_info_->channels, wide_samples = frame->header.blocksize;
- unsigned wide_sample, sample, channel;
+ unsigned wide_sample, offset_sample, channel;
(void)decoder;
if(file_info_->abort_flag)
return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
- for(sample = samples_in_reservoir_ * channels, wide_sample = 0; wide_sample < wide_samples; wide_sample++)
- for(channel = 0; channel < channels; channel++, sample++)
- reservoir_[sample] = (FLAC__int16)buffer[channel][wide_sample];
+ for(offset_sample = wide_samples_in_reservoir_ * channels, wide_sample = 0; wide_sample < wide_samples; wide_sample++)
+ for(channel = 0; channel < channels; channel++, offset_sample++)
+ reservoir_[offset_sample] = buffer[channel][wide_sample];
- samples_in_reservoir_ += wide_samples;
+ wide_samples_in_reservoir_ += wide_samples;
return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
}