some working proto

CMakeLists.txt

@@ -10,6 +10,7 @@ function(em_file name)
             -o ${CMAKE_BINARY_DIR}/${name}.js 
             -s WASM=0
             -g4
+            -s TOTAL_MEMORY=64MB
             )
 endfunction(em_file)
 

decoder.cpp

@@ -2,30 +2,27 @@
 #include <iostream>
 
 Decoder::Decoder():
-state(empty),
 sampleRate(0),
 channels(0),
 cachedLength(0),
 samplesPerFrame(0),
-glue(new uint8_t[GLUE_LENGTH]),
+buffer(new uint8_t[BUFFER_LENGTH]),
-cachedNext(NULL),
-cachedThis(NULL),
-cachedError(MAD_ERROR_NONE),
 cached(false),
 synth(new mad_synth()),
 stream(new mad_stream()),
 frame(new mad_frame()),
-context(0),
+context(0)
-pending()
 {
-    for (int i = 0; i < GLUE_LENGTH; ++i) {
+    for (int i = 0; i < BUFFER_LENGTH; ++i) {
-        glue[i] = 0;
+        buffer[i] = 0;
     }
     
     mad_frame_init(frame);
     mad_stream_init(stream);
     mad_synth_init(synth);
     
+    mad_stream_buffer(stream, buffer, 0);
+    
     emscripten::val AudioContext = emscripten::val::global("AudioContext");
     if (!AudioContext.as<bool>()) {
         AudioContext = emscripten::val::global("webkitAudioContext");
@@ -46,52 +43,23 @@ Decoder::~Decoder()
     delete stream;
     delete frame;
     
-    delete[] glue;
+    delete[] buffer;
 }
 
 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;
+    uint8_t* bf = (uint8_t(*))bufferPtr;
-    RawBuffer rb = {buffer, length, 0, 0};
+    uint64_t ol = stream->bufend - stream->buffer;
-    pending.push_back(rb);
     
-    switch (state) {
+    for (int i = 0; i < length; ++i) {
-        case empty:
+        buffer[ol + i] = bf[i];
-            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;
     }
+    //free(bf);
+    
+    stream->bufend = stream->bufend + length;
+    cached = false;
+    framesLeft();
 }
 
 emscripten::val Decoder::decode(uint32_t count)
@@ -108,7 +76,7 @@ emscripten::val Decoder::decode(uint32_t count)
             chans[i] = ret.call<emscripten::val>("getChannelData", i);
         } 
         
-        for (int i = 0; success < available; ++i) {
+        for (int i = 0; i < available; ++i) {
             int res = mad_frame_decode(frame, stream);
             
             if (res == 0) {
@@ -137,8 +105,7 @@ emscripten::val Decoder::decode(uint32_t count)
         std::cout << "Processed " << available << " frames, " << success << " successfully, last error " << mad_stream_errorstr(stream) << std::endl;
         
         if (cachedLength == 0) {
-            cached = false;
+            framesLeft();
-            prepareNextBuffer();
         }
     }
     
@@ -147,20 +114,17 @@ emscripten::val Decoder::decode(uint32_t count)
 
 bool Decoder::hasMore() const
 {
-    if (pending.size() == 1) {
+    return stream->bufend != stream->buffer && stream->error != MAD_ERROR_BUFLEN;
-        return stream->error != MAD_ERROR_BUFLEN;
-    } else {
-        return true;
-    }
 }
 
 uint32_t Decoder::framesLeft(uint32_t max)
 {
-    if (state == empty || state == onGlueHalf) {
+    if (!hasMore()) {
         return 0;
     }
     
     if (cached == false) {
+        bool found = false;
         mad_stream probe;
         mad_header ph;
         initializeProbe(probe);
@@ -168,6 +132,7 @@ uint32_t Decoder::framesLeft(uint32_t max)
         
         while (cachedLength < max) {
             if (mad_header_decode(&ph, &probe) == 0) {
+                found = true;
                 if (sampleRate == 0) {
                     sampleRate = ph.samplerate;
                     channels = MAD_NCHANNELS(&ph);
@@ -181,6 +146,9 @@ uint32_t Decoder::framesLeft(uint32_t max)
                     ++cachedLength;
                 }
             } else {
+                if (!found) {
+                    stream->next_frame = probe.next_frame;
+                }
                 std::cout << "framesLeft error: " << mad_stream_errorstr(&probe) << std::endl;
                 if (!MAD_RECOVERABLE(probe.error)) {
                     break;
@@ -188,9 +156,6 @@ uint32_t Decoder::framesLeft(uint32_t max)
             }
         }
         
-        cachedNext = probe.next_frame;
-        cachedThis = probe.this_frame;
-        cachedError = probe.error;
         mad_header_finish(&ph);
         mad_stream_finish(&probe);
         std::cout << cachedLength << " frames are available for decoding" << std::endl;
@@ -200,69 +165,6 @@ uint32_t Decoder::framesLeft(uint32_t max)
     return std::min(cachedLength, max);
 }
 
-void Decoder::pullBuffer()
-{
-    if (cached == false) {
-        std::cout << "Error in pullBuffer method!" << std::endl;
-    }
-    stream->this_frame = cachedThis;
-    stream->next_frame = cachedNext;
-    stream->error = cachedError;
-}
-
-void Decoder::changeBuffer()
-{
-    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;
-            
-            switchBuffer(pending[0].ptr, pending[0].length);
-            
-            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);
@@ -286,37 +188,3 @@ void Decoder::initializeProbe(mad_stream& probe)
     //probe.options = stream->options;
     //probe.error = stream->error;
 }
-
-void Decoder::switchToGlue()
-{
-    std::cout << "Switching to glue" << std::endl;
-    switchBuffer(glue, GLUE_LENGTH);
-    
-    std::cout << "Freeing the drained fragment" << std::endl;
-    free(pending[0].ptr);
-    pending.pop_front();
-}
-
-void Decoder::switchBuffer(uint8_t* bufferPtr, uint32_t length)
-{
-    uint32_t left;
-    
-    if (stream->error != MAD_ERROR_BUFLEN) {
-        std::cout << "WARNING: Switching buffers while the previous one is not drained, error: " << mad_stream_errorstr(stream) << std::endl;
-    }
-    if (stream->next_frame != NULL) {
-        left = stream->bufend - stream->next_frame;
-    } else {
-        std::cout << "WARNING: not supposed to happen" << std::endl;
-    }
-    
-    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;
-    }
-    
-    mad_stream_buffer(stream, bufferPtr + GLUE_LENGTH / 2 - left, length - (GLUE_LENGTH / 2 - left));
-    stream->error = MAD_ERROR_NONE;
-    
-    while (mad_header_decode(&frame->header, stream) != 0 && stream->error != MAD_ERROR_BUFLEN) {}
-}

decoder.h

@@ -9,7 +9,7 @@
 #include <emscripten/val.h>
 #include "mad.h"
 
-#define GLUE_LENGTH 6000
+#define BUFFER_LENGTH 30000000
 
 class Decoder {
 public:
@@ -22,32 +22,11 @@ public:
     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;
+    uint8_t* buffer;
-    uint8_t const* cachedNext;
-    uint8_t const* cachedThis;
-    mad_error cachedError;
     bool cached;
     
     mad_synth* synth;
@@ -55,15 +34,9 @@ private:
     mad_frame* frame;
     emscripten::val context;
     
-    std::deque<RawBuffer> pending;
-    
 private:
-    void pullBuffer();
-    void changeBuffer();
-    void prepareNextBuffer();
     void initializeProbe(mad_stream& probe);
-    void switchToGlue();
+
-    void switchBuffer(uint8_t* bufferPtr, uint32_t length);
 };
 
 #endif // DECODER_H

index.html

@@ -12,8 +12,8 @@
   <script src="wrapper.js"></script>
     <input type="file" id="file" name="file" />
   <script>
-    var minPortion = 20480;
+    var minPortion = 60000;
-    var maxPortion = 40960;
+    var maxPortion = 100000;
     var time = 0;
     var ctx = new AudioContext();
     ctx.suspend();