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Basic decoding with edge effects

This commit is contained in:
Blue 2019-01-14 05:19:37 +03:00
parent aa8ac249a0
commit 1f40231b9b
6 changed files with 486 additions and 172 deletions
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4
CMakeLists.txt
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@ -1,8 +1,11 @@
cmake_minimum_required(VERSION 3.0)
set(EMO libmad.bc)
function(em_file name)
execute_process(COMMAND
emcc --bind
${CMAKE_SOURCE_DIR}/libmad.bc
${CMAKE_SOURCE_DIR}/decoder.cpp
${CMAKE_SOURCE_DIR}/${name}.cpp
-o ${CMAKE_BINARY_DIR}/${name}.js
-s WASM=0
@ -13,3 +16,4 @@ endfunction(em_file)
configure_file(index.html index.html)
em_file(wrapper)

362
decoder.cpp Normal file
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@ -0,0 +1,362 @@
#include "decoder.h"
#include <iostream>
Decoder::Decoder():
state(empty),
sampleRate(0),
channels(0),
cachedLength(0),
samplesPerFrame(0),
glue(new uint8_t[GLUE_LENGTH]),
lastSync(-1),
cached(false),
synth(),
stream(),
frame(),
context(0),
pending()
{
for (int i = 0; i < GLUE_LENGTH; ++i) {
glue[i] = 0;
}
mad_frame_init(&frame);
mad_stream_init(&stream);
mad_synth_init(&synth);
emscripten::val AudioContext = emscripten::val::global("AudioContext");
if (!AudioContext.as<bool>()) {
AudioContext = emscripten::val::global("webkitAudioContext");
}
context = AudioContext.new_();
}
Decoder::~Decoder()
{
context.call<void>("close");
mad_synth_finish(&synth);
mad_stream_finish(&stream);
mad_frame_finish(&frame);
delete[] glue;
}
void Decoder::addFragment(intptr_t bufferPtr, uint32_t length)
{
if (length < GLUE_LENGTH / 2) {
std::cout << "An attempt to add fragment smaller then half of the glue buffer, ignoring";
return;
}
std::cout << "Adding new fragment " << length << " bytes long" << std::endl;
uint8_t* buffer = (uint8_t(*))bufferPtr;
RawBuffer rb = {buffer, length, 0, 0};
pending.push_back(rb);
std::cout << "The state now is " << state << std::endl;
switch (state) {
case empty:
mad_stream_buffer(&stream, buffer, length);
for (int i = 0; i < GLUE_LENGTH/2; ++i) {
glue[i] = buffer[length - GLUE_LENGTH/2 + i];
}
state = onBufferHalf;
prepareNextBuffer();
break;
case onBufferHalf:
for (int i = 0; i < GLUE_LENGTH/2; ++i) {
glue[GLUE_LENGTH/2 + i] = buffer[i];
}
state = onBufferFull;
break;
case onBufferFull:
break;
case onGlueHalf:
for (int i = 0; i < GLUE_LENGTH/2; ++i) {
glue[GLUE_LENGTH/2 + i] = buffer[i];
}
state = onGlueFull;
cached = false;
prepareNextBuffer();
break;
case onGlueFull:
break;
}
}
emscripten::val Decoder::decode(uint32_t count)
{
emscripten::val ret = emscripten::val::undefined();
int available = framesLeft(count);
int success = 0;
if (available > 0) {
ret = context.call<emscripten::val>("createBuffer", channels, available * samplesPerFrame, sampleRate);
std::vector<emscripten::val> chans(channels, emscripten::val::undefined());
for (int i = 0; i < channels; ++i) {
chans[i] = ret.call<emscripten::val>("getChannelData", i);
}
for (int i = 0; success < available; ++i) {
int res = mad_frame_decode(&frame, &stream);
if (res == 0) {
lastSync = stream.bufend - stream.this_frame;
++success;
} else {
if (MAD_RECOVERABLE(stream.error)) {
std::cout << "Unexpected error during the decoding process: " << mad_stream_errorstr(&stream) << std::endl;
continue;
} else {
break;
}
}
mad_synth_frame(&synth, &frame);
for (int j = 0; j < samplesPerFrame; ++j) {
for (int k = 0; k < channels; ++k) {
float value = mad_f_todouble(synth.pcm.samples[k][j]);
chans[k].set(std::to_string(success * samplesPerFrame + j), emscripten::val(value));
}
}
}
cachedLength -= available;
std::cout << "Processed " << available << " frames, " << success << " successfully, last error " << mad_stream_errorstr(&stream) << std::endl;
if (cachedLength == 0) {
cached = false;
prepareNextBuffer();
}
}
return ret;
}
bool Decoder::hasMore() const
{
if (pending.size() == 1) {
return stream.error != MAD_ERROR_BUFLEN;
} else {
return true;
}
}
uint32_t Decoder::framesLeft(uint32_t max)
{
if (state == empty || state == onGlueHalf) {
cached = true;
return 0;
}
if (cached == false) {
mad_stream probe;
mad_header ph;
initializeProbe(probe);
mad_header_init(&ph);
while (cachedLength < max) {
if (mad_header_decode(&ph, &probe) == 0) {
if (sampleRate == 0) {
sampleRate = ph.samplerate;
channels = MAD_NCHANNELS(&ph);
samplesPerFrame = MAD_NSBSAMPLES(&ph) * 32; //not sure why 32, it's in libmad source
} else {
if (sampleRate != ph.samplerate || channels != MAD_NCHANNELS(&ph) || samplesPerFrame != MAD_NSBSAMPLES(&ph) * 32) {
break;
}
}
if (probe.next_frame > probe.this_frame) {
++cachedLength;
}
} else {
std::cout << "framesLeft::" << mad_stream_errorstr(&probe) << std::endl;
if (!MAD_RECOVERABLE(probe.error)) {
break;
}
}
}
mad_header_finish(&ph);
mad_stream_finish(&probe);
std::cout << cachedLength << " frames are available for decoding" << std::endl;
cached = true;
}
return std::min(cachedLength, max);
}
void Decoder::pullBuffer()
{
mad_header dummy;
mad_header_init(&dummy);
while(stream.error == 0 || MAD_RECOVERABLE(stream.error)) {
mad_header_decode(&dummy, &stream);
std::cout << "pullBuffer:: " << mad_stream_errorstr(&stream) << std::endl;
}
mad_header_finish(&dummy);
}
void Decoder::changeBuffer()
{
uint32_t left;
switch (state) {
case empty:
std::cout << "Wrong state on switchBuffer method - empty, aborting" << std::endl;
case onBufferHalf:
switchToGlue();
state = onGlueHalf;
break;
case onBufferFull:
switchToGlue();
state = onGlueFull;
break;
case onGlueHalf:
std::cout << "Wrong state on switchBuffer method - onGlueHalf, aborting" << std::endl;
break;
case onGlueFull:
std::cout << "Having another fragment " << pending[0].length << " bytes long" << std::endl;
left = (uint64_t)stream.bufend - (uint64_t)stream.next_frame;
// std::cout << "MD_LENGTH_BEFORE: " << stream.anc_bitlen << std::endl;
mad_stream_buffer(&stream, pending[0].ptr, pending[0].length);
//mad_stream_skip(&stream, left);
stream.error = MAD_ERROR_NONE;
if (lastSync != -1) {
if (lastSync > GLUE_LENGTH / 2) {
std::cout << "Error: bytes to read in the buffer are more then glue buffer can fit LASTSYNC (" << lastSync << ")" << std::endl;
throw 1;
}
uint64_t target = (uint64_t)stream.buffer + GLUE_LENGTH / 2 - lastSync;
while ((uint64_t)(stream.this_frame) < target) {
// std::cout << "pulling" << std::endl;
mad_frame_decode(&frame, &stream);
}
stream.error = MAD_ERROR_NONE;
// stream.this_frame = stream.buffer + GLUE_LENGTH / 2 - lastSync;
// stream.next_frame = stream.buffer + GLUE_LENGTH / 2 - left;
// stream.sync = 1;
lastSync = -1;
// mad_bitptr next_frame;
// mad_bit_init(&next_frame, stream.next_frame);
// stream.anc_ptr = stream.ptr;
// stream.anc_bitlen = mad_bit_length(&stream.ptr, &next_frame);
// mad_bit_finish(&next_frame);
//
// std::cout << ", MD_LENGTH_AFTER: " << stream.anc_bitlen << std::endl;
}
for (int i = 0; i < GLUE_LENGTH/2; ++i) {
glue[i] = pending[0].ptr[pending[0].length - GLUE_LENGTH/2 + i];
}
state = onBufferHalf;
if (pending.size() > 1) {
for (int i = 0; i < GLUE_LENGTH/2; ++i) {
glue[GLUE_LENGTH/2 + i] = pending[1].ptr[i];
}
state = onBufferFull;
}
}
cached = false;
}
void Decoder::prepareNextBuffer()
{
bool shift;
do {
shift = false;
framesLeft();
if (cachedLength == 0 && state != empty && state != onGlueHalf) {
pullBuffer();
changeBuffer();
shift = true;
}
} while (shift);
}
void Decoder::initializeProbe(mad_stream& probe)
{
mad_stream_init(&probe);
probe.buffer = stream.buffer;
probe.bufend = stream.bufend;
probe.skiplen = stream.skiplen;
probe.sync = stream.sync;
probe.freerate = stream.freerate;
probe.this_frame = stream.this_frame;
probe.next_frame = stream.next_frame;
probe.ptr.byte = stream.ptr.byte;
probe.ptr.cache = stream.ptr.cache;
probe.ptr.cache = stream.ptr.cache;
probe.anc_ptr.byte = stream.anc_ptr.byte;
probe.anc_ptr.cache = stream.anc_ptr.cache;
probe.anc_ptr.cache = stream.anc_ptr.cache;
probe.anc_bitlen = stream.anc_bitlen;
//probe.main_data = stream.main_data;
//probe.md_len = stream.md_len;
probe.options = stream.options;
probe.error = stream.error;
}
void Decoder::switchToGlue()
{
std::cout << "Switching to glue" << std::endl;
uint32_t left = (uint64_t)stream.bufend - (uint64_t)stream.next_frame;
if (left > GLUE_LENGTH / 2) {
std::cout << "Error: bytes to read in the buffer are more then glue buffer can fit (" << left << ")" << std::endl;
throw 1;
}
// std::cout << "MD_LENGTH_BEFORE: " << stream.anc_bitlen << std::endl;
mad_stream_buffer(&stream, glue, GLUE_LENGTH);
if (lastSync != -1) {
if (lastSync > GLUE_LENGTH / 2) {
std::cout << "Error: bytes to read in the buffer are more then glue buffer can fit LASTSYNC (" << lastSync << ")" << std::endl;
throw 1;
}
uint64_t target = (uint64_t)stream.bufend - GLUE_LENGTH / 2 - lastSync;
while ((uint64_t)(stream.this_frame) < target) {
// std::cout << "pulling" << std::endl;
mad_frame_decode(&frame, &stream);
}
stream.error = MAD_ERROR_NONE;
// stream.this_frame = stream.bufend - GLUE_LENGTH / 2 - lastSync;
// stream.next_frame = stream.bufend - GLUE_LENGTH / 2 - left;
// stream.sync = 1;
// mad_bitptr next_frame;
// mad_bit_init(&next_frame, stream.next_frame);
// stream.anc_ptr = stream.ptr;
// stream.anc_bitlen = mad_bit_length(&stream.ptr, &next_frame);
// mad_bit_finish(&next_frame);
//
// std::cout << ", MD_LENGTH_AFTER: " << stream.anc_bitlen << std::endl;
lastSync = -1;
}
//mad_stream_skip(&stream, left);
stream.error = MAD_ERROR_NONE;
//std::cout << "SKIPLEN (" << stream.skiplen << ")" << std::endl;
std::cout << "Freeing the drained fragment" << std::endl;
free(pending[0].ptr);
pending.pop_front();
}

66
decoder.h Normal file
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@ -0,0 +1,66 @@
#ifndef DECODER_H
#define DECODER_H
/**
* @todo write docs
*/
#include <deque>
#include <emscripten/val.h>
#include "mad.h"
#define GLUE_LENGTH 10240
class Decoder {
public:
Decoder();
~Decoder();
void addFragment(intptr_t bufferPtr, uint32_t length);
emscripten::val decode(uint32_t count = UINT32_MAX);
bool hasMore() const;
uint32_t framesLeft(uint32_t max = UINT32_MAX);
private:
enum State {
empty,
onBufferHalf,
onBufferFull,
onGlueHalf,
onGlueFull
};
struct RawBuffer {
uint8_t* ptr;
uint32_t length;
uint32_t offset;
uint32_t gueard;
};
State state;
uint32_t sampleRate;
uint8_t channels;
uint32_t cachedLength;
uint16_t samplesPerFrame;
uint8_t* glue;
int32_t lastSync;
bool cached;
mad_synth synth;
mad_stream stream;
mad_frame frame;
emscripten::val context;
std::deque<RawBuffer> pending;
private:
void pullBuffer();
void changeBuffer();
void prepareNextBuffer();
void initializeProbe(mad_stream& probe);
void switchToGlue();
};
#endif // DECODER_H

62
index.html
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@ -12,24 +12,24 @@
<script src="wrapper.js"></script>
<input type="file" id="file" name="file" />
<script>
var minPortion = 20480;
var maxPortion = 40960;
var time = 0;
var ctx = new AudioContext();
ctx.suspend();
var decoder;
var fragments = [];
var noize = [];
var decoding = false;
function onChange(e) {
var file = e.target.files[0];
var reader = new FileReader();
reader.onload = function(e) {
decoder = new Module.Decoder();
var buffer = reader.result;
var src = new Uint8Array(buffer);
var ptr = Module._malloc(buffer.byteLength);
var arr = new Uint8Array(Module.HEAPU8.buffer, ptr, buffer.byteLength);
arr.set(src, 0);
createFileFragments(reader.result);
decoder.addFragment(ptr, buffer.byteLength);
schedule();
scheduleData();
ctx.resume();
}
reader.readAsArrayBuffer(file);
@ -37,8 +37,9 @@
}
function schedule() {
decoding = false;
if (decoder.hasMore()) {
var audio = decoder.decode(50);
var audio = decoder.decode(20);
if (audio) {
var source = ctx.createBufferSource();
source.buffer = audio;
@ -47,14 +48,55 @@
time += audio.duration;
setTimeout(schedule, Math.floor(audio.duration * 200));
decoding = true;
} else {
decoder.delete();
//decoder.delete();
}
} else {
decoder.delete();
//decoder.delete();
}
}
function scheduleData() {
if (fragments.length) {
var frag = fragments.shift();
decoder.addFragment(frag.ptr, frag.length);
if (fragments.length) {
setTimeout(scheduleData, 50);
}
if (!decoding) {
schedule();
}
}
}
function createFileFragments(buffer) {
var src = new Uint8Array(buffer);
var shoved = 0;
while (shoved !== src.length) {
var ps = Math.min(Math.floor(Math.random() * (maxPortion - minPortion) + minPortion), src.length - shoved);
var ptr = Module._malloc(ps);
var arr = new Uint8Array(Module.HEAPU8.buffer, ptr, ps);
var portion = new Uint8Array(buffer, shoved, ps)
arr.set(portion, 0);
shoved += ps;
fragments.push({
ptr: ptr,
length: ps
});
noize.push(Module._malloc(256));
}
}
document.getElementById("file").addEventListener("change", onChange, false);
</script>
</body>

139
wrapper.cpp
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@ -70,142 +70,3 @@ void MadSynth::frame(const mad_frame* frame)
{
mad_synth_frame(this, frame);
}
Decoder::Decoder():
sampleRate(0),
channels(0),
cachedLength(0),
samplesPerFrame(0),
currentBuffer(0),
currentBufferLength(0),
synth(),
stream(),
frame(),
context(0)
{
mad_frame_init(&frame);
mad_stream_init(&stream);
mad_synth_init(&synth);
emscripten::val AudioContext = emscripten::val::global("AudioContext");
if (!AudioContext.as<bool>()) {
printf("No global AudioContext, trying webkitAudioContext\n");
AudioContext = emscripten::val::global("webkitAudioContext");
}
printf("Got an AudioContext\n");
context = AudioContext.new_();
}
Decoder::~Decoder()
{
context.call<void>("close");
mad_synth_finish(&synth);
mad_stream_finish(&stream);
mad_frame_finish(&frame);
if (currentBuffer != 0) {
free(currentBuffer);
}
}
void Decoder::addFragment(intptr_t bufferPtr, unsigned long length)
{
if (currentBuffer != 0) {
printf("Adding more then 1 fragment is not supported yet");
throw 1;
}
currentBuffer = (unsigned char(*))bufferPtr;
currentBufferLength = length;
mad_stream_buffer(&stream, currentBuffer, currentBufferLength);
framesLeft();
}
emscripten::val Decoder::decode(uint32_t count)
{
emscripten::val ret = emscripten::val::undefined();
int available = framesLeft(count);
if (available > 0) {
ret = context.call<val>("createBuffer", channels, available * samplesPerFrame, sampleRate);
std::vector<emscripten::val> chans(channels, emscripten::val::undefined());
for (int i = 0; i < channels; ++i) {
chans[i] = ret.call<val>("getChannelData", i);
}
for (int i = 0; i < available; ++i) {
mad_frame_decode(&frame, &stream);
mad_synth_frame(&synth, &frame);
for (int j = 0; j < samplesPerFrame; ++j) {
for (int k = 0; k < channels; ++k) {
float value = mad_f_todouble(synth.pcm.samples[k][j]);
chans[k].set(std::to_string(i * samplesPerFrame + j), val(value));
}
}
}
cachedLength -= available;
if (cachedLength == 0) {
framesLeft();
}
}
return ret;
}
bool Decoder::hasMore() const
{
if (currentBuffer == 0) {
return false;
}
return stream.error != MAD_ERROR_BUFLEN;
}
uint32_t Decoder::framesLeft(uint32_t max)
{
if (currentBuffer == 0) {
return 0;
}
if (cachedLength == 0) {
mad_stream probe;
mad_header ph;
mad_stream_init(&probe);
mad_header_init(&ph);
mad_stream_buffer(&probe, currentBuffer, currentBufferLength);
mad_stream_skip(&probe, stream.skiplen);
while (cachedLength < max) {
if (mad_header_decode(&ph, &probe) == 0) {
if (sampleRate == 0) {
sampleRate = ph.samplerate;
channels = MAD_NCHANNELS(&ph);
samplesPerFrame = MAD_NSBSAMPLES(&ph) * 32; //not sure why 32, it's in libmad source
} else {
if (sampleRate != ph.samplerate || channels != MAD_NCHANNELS(&ph) || samplesPerFrame != MAD_NSBSAMPLES(&ph) * 32) {
break;
}
}
++cachedLength;
} else {
if (!MAD_RECOVERABLE(probe.error)) {
std::cout << "framesLeft::" << probe.error << std::endl;
break;
}
}
}
mad_header_finish(&ph);
mad_stream_finish(&probe);
}
return std::min(cachedLength, max);
}

25
wrapper.h
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@ -5,6 +5,7 @@
#include <emscripten/val.h>
#include "mad.h"
#include "decoder.h"
using namespace emscripten;
@ -118,29 +119,7 @@ public:
MadSynth* mad_synth_create();
class Decoder {
public:
Decoder();
~Decoder();
void addFragment(intptr_t bufferPtr, unsigned long length);
val decode(uint32_t count = UINT32_MAX);
bool hasMore() const;
uint32_t framesLeft(uint32_t max = UINT32_MAX);
private:
uint32_t sampleRate;
uint8_t channels;
uint32_t cachedLength;
uint16_t samplesPerFrame;
unsigned char* currentBuffer;
unsigned long currentBufferLength;
mad_synth synth;
mad_stream stream;
mad_frame frame;
val context;
};
EMSCRIPTEN_BINDINGS(jsmad) {
enum_<mad_layer>("mad_layer")