Add Demand Feed audio streaming support back to ASS audiolib. This is from the Rise of the Triad source release.

source/audiolib/include/fx_man.h

@@ -69,6 +69,8 @@ int FX_PlayRaw(char *ptr, uint32_t ptrlength, int rate, int pitchoffset, int vol
 int FX_PlayLoopedRaw(char *ptr, uint32_t ptrlength, char *loopstart, char *loopend, int rate,
     int pitchoffset, int vol, int left, int right, int priority, float volume, intptr_t callbackval);
 
+int FX_StartDemandFeedPlayback(void (*function)(const char** ptr, uint32_t* length), int rate, int pitchoffset,
+                    int vol, int left, int right, int priority, fix16_t volume, uint32_t callbackval);
 
 int FX_SetPrintf(void(*function)(const char *, ...));
 

source/audiolib/include/multivoc.h

@@ -105,6 +105,9 @@ int MV_PlayVOC3D(char *ptr, uint32_t length, int loophow, int pitchoffset, int a
 int MV_PlayVOC(char *ptr, uint32_t length, int loopstart, int loopend, int pitchoffset, int vol,
                int left, int right, int priority, float volume, intptr_t callbackval);
 
+int MV_StartDemandFeedPlayback(void (*function)(const char** ptr, uint32_t* length), int rate,
+                int pitchoffset, int vol, int left, int right, int priority, fix16_t volume, uint32_t callbackval);
+
 decltype(MV_PlayVOC3D) MV_PlayWAV3D;
 decltype(MV_PlayVOC)   MV_PlayWAV;
 decltype(MV_PlayVOC3D) MV_PlayVorbis3D;

source/audiolib/src/_multivc.h

@@ -158,6 +158,8 @@ typedef struct VoiceNode
 
     uint32_t (*mix)(struct VoiceNode *, uint32_t);
 
+    void (*DemandFeed)(const char** ptr, uint32_t* length);
+
     const char *sound;
 
     float LeftVolume, LeftVolumeDest;

source/audiolib/src/fx_man.cpp

@@ -225,3 +225,36 @@ int FX_SetPrintf(void (*function)(const char *, ...))
 
     return FX_Ok;
 }
+
+/*---------------------------------------------------------------------
+   Function: FX_StartDemandFeedPlayback
+
+   Plays a digitized sound from a user controlled buffering system.
+---------------------------------------------------------------------*/
+
+int FX_StartDemandFeedPlayback
+(
+    void (*function)(const char** ptr, uint32_t* length),
+    int rate,
+    int pitchoffset,
+    int vol,
+    int left,
+    int right,
+    int priority,
+    fix16_t volume,
+    uint32_t callbackval
+)
+
+{
+    int handle;
+
+    handle = MV_StartDemandFeedPlayback(function, rate,
+        pitchoffset, vol, left, right, priority, volume, callbackval);
+    if (handle < MV_Ok)
+    {
+        FX_SetErrorCode(FX_MultiVocError);
+        handle = FX_Warning;
+    }
+
+    return(handle);
+}

source/audiolib/src/multivoc.cpp

@@ -899,3 +899,103 @@ const char *MV_ErrorString(int ErrorNumber)
     }
 }
 
+/*---------------------------------------------------------------------
+   Function: MV_GetNextDemandFeedBlock
+
+   Controls playback of demand fed data.
+---------------------------------------------------------------------*/
+
+playbackstatus MV_GetNextDemandFeedBlock
+(
+    VoiceNode* voice
+)
+
+{
+    if (voice->BlockLength > 0)
+    {
+        voice->position -= voice->length;
+        voice->sound += voice->length >> 16;
+        voice->length = min(voice->BlockLength, 0x8000u);
+        voice->BlockLength -= voice->length;
+        voice->length <<= 16;
+
+        return(KeepPlaying);
+    }
+
+    if (voice->DemandFeed == NULL)
+    {
+        return(NoMoreData);
+    }
+
+    voice->position = 0;
+    (voice->DemandFeed)(&voice->sound, &voice->BlockLength);
+    voice->length = min(voice->BlockLength, 0x8000u);
+    voice->BlockLength -= voice->length;
+    voice->length <<= 16;
+
+    if ((voice->length > 0) && (voice->sound != NULL))
+    {
+        return(KeepPlaying);
+    }
+    return(NoMoreData);
+}
+
+/*---------------------------------------------------------------------
+   Function: MV_StartDemandFeedPlayback
+
+   Plays a digitized sound from a user controlled buffering system.
+---------------------------------------------------------------------*/
+
+int MV_StartDemandFeedPlayback
+(
+    void (*function)(const char** ptr, uint32_t* length),
+    int rate,
+    int pitchoffset,
+    int vol,
+    int left,
+    int right,
+    int priority,
+    fix16_t volume,
+    uint32_t callbackval
+)
+
+{
+    VoiceNode* voice;
+
+    if (!MV_Installed)
+    {
+        MV_SetErrorCode(MV_NotInstalled);
+        return(MV_Error);
+    }
+
+    // Request a voice from the voice pool
+    voice = MV_AllocVoice(priority);
+    if (voice == NULL)
+    {
+        MV_SetErrorCode(MV_NoVoices);
+        return(MV_Error);
+    }
+
+//    voice->wavetype = FMT_DEMANDFED;
+    voice->bits = 8;
+    voice->channels = 1;
+    voice->GetSound = MV_GetNextDemandFeedBlock;
+    voice->NextBlock = NULL;
+    voice->DemandFeed = function;
+    voice->LoopStart = NULL;
+    voice->LoopCount = 0;
+    voice->BlockLength = 0;
+    voice->position = 0;
+    voice->sound = NULL;
+    voice->length = 0;
+    voice->next = NULL;
+    voice->prev = NULL;
+    voice->priority = priority;
+    voice->callbackval = callbackval;
+
+    MV_SetVoicePitch(voice, rate, pitchoffset);
+    MV_SetVoiceVolume(voice, vol, left, right, volume);
+    MV_PlayVoice(voice);
+
+    return(voice->handle);
+}