Add some APIs to data sources:

* ma_data_source_get_cursor_in_pcm_frames()
  * ma_data_source_get_length_in_pcm_frames()

When the data source has no notion of a cursor or length, these return
MA_NOT_IMPLEMENTED to let the caller know about it. This is returned
when a custom data source leaves these functions unimplemented.

ma_decoder, ma_audio_buffer, ma_waveform and ma_noise have all been
updated to support these new functions.

miniaudio.h

@@ -5244,6 +5244,8 @@ typedef struct
     ma_result (* onMap)(ma_data_source* pDataSource, void** ppFramesOut, ma_uint64* pFrameCount);   /* Returns MA_AT_END if the end has been reached. This should be considered successful. */
     ma_result (* onUnmap)(ma_data_source* pDataSource, ma_uint64 frameCount);
     ma_result (* onGetDataFormat)(ma_data_source* pDataSource, ma_format* pFormat, ma_uint32* pChannels, ma_uint32* pSampleRate);
+    ma_result (* onGetCursor)(ma_data_source* pDataSource, ma_uint64* pCursor);
+    ma_result (* onGetLength)(ma_data_source* pDataSource, ma_uint64* pLength);
 } ma_data_source_callbacks;
 
 MA_API ma_result ma_data_source_read_pcm_frames(ma_data_source* pDataSource, void* pFramesOut, ma_uint64 frameCount, ma_uint64* pFramesRead, ma_bool32 loop);   /* Must support pFramesOut = NULL in which case a forward seek should be performed. */
@@ -5252,6 +5254,8 @@ MA_API ma_result ma_data_source_seek_to_pcm_frame(ma_data_source* pDataSource, m
 MA_API ma_result ma_data_source_map(ma_data_source* pDataSource, void** ppFramesOut, ma_uint64* pFrameCount);
 MA_API ma_result ma_data_source_unmap(ma_data_source* pDataSource, ma_uint64 frameCount);       /* Returns MA_AT_END if the end has been reached. This should be considered successful. */
 MA_API ma_result ma_data_source_get_data_format(ma_data_source* pDataSource, ma_format* pFormat, ma_uint32* pChannels, ma_uint32* pSampleRate);
+MA_API ma_result ma_data_source_get_cursor_in_pcm_frames(ma_data_source* pDataSource, ma_uint64* pCursor);
+MA_API ma_result ma_data_source_get_length_in_pcm_frames(ma_data_source* pDataSource, ma_uint64* pLength);    /* Returns MA_NOT_IMPLEMENTED if the length is unknown or cannot be determined. Decoders can return this. */
 
 
 typedef struct
@@ -41315,6 +41319,48 @@ MA_API ma_result ma_data_source_get_data_format(ma_data_source* pDataSource, ma_
     return MA_SUCCESS;
 }
 
+MA_API ma_result ma_data_source_get_cursor_in_pcm_frames(ma_data_source* pDataSource, ma_uint64* pCursor)
+{
+    ma_data_source_callbacks* pCallbacks = (ma_data_source_callbacks*)pDataSource;
+
+    if (pCursor == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    pCursor = 0;
+
+    if (pCallbacks == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    if (pCallbacks->onGetCursor == NULL) {
+        return MA_NOT_IMPLEMENTED;
+    }
+
+    return pCallbacks->onGetCursor(pDataSource, pCursor);
+}
+
+MA_API ma_result ma_data_source_get_length_in_pcm_frames(ma_data_source* pDataSource, ma_uint64* pLength)
+{
+    ma_data_source_callbacks* pCallbacks = (ma_data_source_callbacks*)pDataSource;
+
+    if (pLength == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    pLength = 0;
+
+    if (pCallbacks == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    if (pCallbacks->onGetLength == NULL) {
+        return MA_NOT_IMPLEMENTED;
+    }
+
+    return pCallbacks->onGetLength(pDataSource, pLength);
+}
+
 
 
 MA_API ma_audio_buffer_config ma_audio_buffer_config_init(ma_format format, ma_uint32 channels, ma_uint64 sizeInFrames, const void* pData, const ma_allocation_callbacks* pAllocationCallbacks)
@@ -41373,6 +41419,24 @@ static ma_result ma_audio_buffer__data_source_on_get_data_format(ma_data_source*
     return MA_SUCCESS;
 }
 
+static ma_result ma_audio_buffer__data_source_on_get_cursor(ma_data_source* pDataSource, ma_uint64* pCursor)
+{
+    ma_audio_buffer* pAudioBuffer = (ma_audio_buffer*)pDataSource;
+
+    *pCursor = pAudioBuffer->cursor;
+
+    return MA_SUCCESS;
+}
+
+static ma_result ma_audio_buffer__data_source_on_get_length(ma_data_source* pDataSource, ma_uint64* pLength)
+{
+    ma_audio_buffer* pAudioBuffer = (ma_audio_buffer*)pDataSource;
+
+    *pLength = pAudioBuffer->sizeInFrames;
+
+    return MA_SUCCESS;
+}
+
 static ma_result ma_audio_buffer_init_ex(const ma_audio_buffer_config* pConfig, ma_bool32 doCopy, ma_audio_buffer* pAudioBuffer)
 {
     if (pAudioBuffer == NULL) {
@@ -41394,6 +41458,8 @@ static ma_result ma_audio_buffer_init_ex(const ma_audio_buffer_config* pConfig,
     pAudioBuffer->ds.onMap           = ma_audio_buffer__data_source_on_map;
     pAudioBuffer->ds.onUnmap         = ma_audio_buffer__data_source_on_unmap;
     pAudioBuffer->ds.onGetDataFormat = ma_audio_buffer__data_source_on_get_data_format;
+    pAudioBuffer->ds.onGetCursor     = ma_audio_buffer__data_source_on_get_cursor;
+    pAudioBuffer->ds.onGetLength     = ma_audio_buffer__data_source_on_get_length;
     pAudioBuffer->format             = pConfig->format;
     pAudioBuffer->channels           = pConfig->channels;
     pAudioBuffer->cursor             = 0;
@@ -44433,6 +44499,27 @@ static ma_result ma_decoder__data_source_on_get_data_format(ma_data_source* pDat
     return MA_SUCCESS;
 }
 
+static ma_result ma_decoder__data_source_on_get_cursor(ma_data_source* pDataSource, ma_uint64* pCursor)
+{
+    ma_decoder* pDecoder = (ma_decoder*)pDataSource;
+
+    *pCursor = pDecoder->readPointerInPCMFrames;
+
+    return MA_SUCCESS;
+}
+
+static ma_result ma_decoder__data_source_on_get_length(ma_data_source* pDataSource, ma_uint64* pLength)
+{
+    ma_decoder* pDecoder = (ma_decoder*)pDataSource;
+
+    *pLength = ma_decoder_get_length_in_pcm_frames(pDecoder);
+    if (*pLength == 0) {
+        return MA_NOT_IMPLEMENTED;
+    }
+
+    return MA_SUCCESS;
+}
+
 static ma_result ma_decoder__preinit(ma_decoder_read_proc onRead, ma_decoder_seek_proc onSeek, void* pUserData, const ma_decoder_config* pConfig, ma_decoder* pDecoder)
 {
     ma_result result;
@@ -44452,6 +44539,8 @@ static ma_result ma_decoder__preinit(ma_decoder_read_proc onRead, ma_decoder_see
     pDecoder->ds.onRead          = ma_decoder__data_source_on_read;
     pDecoder->ds.onSeek          = ma_decoder__data_source_on_seek;
     pDecoder->ds.onGetDataFormat = ma_decoder__data_source_on_get_data_format;
+    pDecoder->ds.onGetCursor     = ma_decoder__data_source_on_get_cursor;
+    pDecoder->ds.onGetLength     = ma_decoder__data_source_on_get_length;
 
     pDecoder->onRead    = onRead;
     pDecoder->onSeek    = onSeek;
@@ -46220,6 +46309,15 @@ static ma_result ma_waveform__data_source_on_get_data_format(ma_data_source* pDa
     return MA_SUCCESS;
 }
 
+static ma_result ma_waveform__data_source_on_get_cursor(ma_data_source* pDataSource, ma_uint64* pCursor)
+{
+    ma_waveform* pWaveform = (ma_waveform*)pDataSource;
+
+    *pCursor = (ma_uint64)(pWaveform->time / pWaveform->advance);
+
+    return MA_SUCCESS;
+}
+
 MA_API ma_result ma_waveform_init(const ma_waveform_config* pConfig, ma_waveform* pWaveform)
 {
     if (pWaveform == NULL) {
@@ -46230,6 +46328,8 @@ MA_API ma_result ma_waveform_init(const ma_waveform_config* pConfig, ma_waveform
     pWaveform->ds.onRead          = ma_waveform__data_source_on_read;
     pWaveform->ds.onSeek          = ma_waveform__data_source_on_seek;
     pWaveform->ds.onGetDataFormat = ma_waveform__data_source_on_get_data_format;
+    pWaveform->ds.onGetCursor     = ma_waveform__data_source_on_get_cursor;
+    pWaveform->ds.onGetLength     = NULL;   /* Intentionally set to NULL since there's no notion of a length in waveforms. */
     pWaveform->config             = *pConfig;
     pWaveform->advance            = 1.0 / pWaveform->config.sampleRate;
     pWaveform->time               = 0;
@@ -46619,6 +46719,8 @@ MA_API ma_result ma_noise_init(const ma_noise_config* pConfig, ma_noise* pNoise)
     pNoise->ds.onRead          = ma_noise__data_source_on_read;
     pNoise->ds.onSeek          = ma_noise__data_source_on_seek;  /* <-- No-op for noise. */
     pNoise->ds.onGetDataFormat = ma_noise__data_source_on_get_data_format;
+    pNoise->ds.onGetCursor     = NULL;  /* No notion of a cursor for noise. */
+    pNoise->ds.onGetLength     = NULL;  /* No notion of a length for noise. */
     pNoise->config             = *pConfig;
     ma_lcg_seed(&pNoise->lcg, pConfig->seed);
 

research/ma_engine.h

@@ -594,7 +594,9 @@ struct ma_resource_manager_data_stream
     ma_uint32 flags;                        /* The flags that were passed used to initialize the stream. */
     ma_decoder decoder;                     /* Used for filling pages with data. This is only ever accessed by the job thread. The public API should never touch this. */
     ma_bool32 isDecoderInitialized;         /* Required for determining whether or not the decoder should be uninitialized in MA_JOB_FREE_DATA_STREAM. */
+    ma_uint64 totalLengthInPCMFrames;       /* This is calculated when first loaded by the MA_JOB_LOAD_DATA_STREAM. */
     ma_uint32 relativeCursor;               /* The playback cursor, relative to the current page. Only ever accessed by the public API. Never accessed by the job thread. */
+    ma_uint64 absoluteCursor;               /* The playback cursor, in absolute position starting from the start of the file. */
     ma_uint32 currentPageIndex;             /* Toggles between 0 and 1. Index 0 is the first half of pPageData. Index 1 is the second half. Only ever accessed by the public API. Never accessed by the job thread. */
     ma_uint32 executionCounter;             /* For allocating execution orders for jobs. */
     ma_uint32 executionPointer;             /* For managing the order of execution for asynchronous jobs relating to this object. Incremented as jobs complete processing. */
@@ -666,6 +668,8 @@ MA_API ma_result ma_resource_manager_data_buffer_seek_to_pcm_frame(ma_resource_m
 MA_API ma_result ma_resource_manager_data_buffer_map(ma_resource_manager_data_buffer* pDataBuffer, void** ppFramesOut, ma_uint64* pFrameCount);
 MA_API ma_result ma_resource_manager_data_buffer_unmap(ma_resource_manager_data_buffer* pDataBuffer, ma_uint64 frameCount);
 MA_API ma_result ma_resource_manager_data_buffer_get_data_format(ma_resource_manager_data_buffer* pDataBuffer, ma_format* pFormat, ma_uint32* pChannels, ma_uint32* pSampleRate);
+MA_API ma_result ma_resource_manager_data_buffer_get_cursor_in_pcm_frames(ma_resource_manager_data_buffer* pDataBuffer, ma_uint64* pCursor);
+MA_API ma_result ma_resource_manager_data_buffer_get_length_in_pcm_frames(ma_resource_manager_data_buffer* pDataBuffer, ma_uint64* pLength);
 MA_API ma_result ma_resource_manager_data_buffer_result(const ma_resource_manager_data_buffer* pDataBuffer);
 MA_API ma_result ma_resource_manager_data_buffer_set_looping(ma_resource_manager_data_buffer* pDataBuffer, ma_bool32 isLooping);
 MA_API ma_result ma_resource_manager_data_buffer_get_looping(const ma_resource_manager_data_buffer* pDataBuffer, ma_bool32* pIsLooping);
@@ -679,6 +683,8 @@ MA_API ma_result ma_resource_manager_data_stream_seek_to_pcm_frame(ma_resource_m
 MA_API ma_result ma_resource_manager_data_stream_map(ma_resource_manager_data_stream* pDataStream, void** ppFramesOut, ma_uint64* pFrameCount);
 MA_API ma_result ma_resource_manager_data_stream_unmap(ma_resource_manager_data_stream* pDataStream, ma_uint64 frameCount);
 MA_API ma_result ma_resource_manager_data_stream_get_data_format(ma_resource_manager_data_stream* pDataStream, ma_format* pFormat, ma_uint32* pChannels, ma_uint32* pSampleRate);
+MA_API ma_result ma_resource_manager_data_stream_get_cursor_in_pcm_frames(ma_resource_manager_data_stream* pDataStream, ma_uint64* pCursor);
+MA_API ma_result ma_resource_manager_data_stream_get_length_in_pcm_frames(ma_resource_manager_data_stream* pDataStream, ma_uint64* pLength);
 MA_API ma_result ma_resource_manager_data_stream_result(const ma_resource_manager_data_stream* pDataStream);
 MA_API ma_result ma_resource_manager_data_stream_set_looping(ma_resource_manager_data_stream* pDataStream, ma_bool32 isLooping);
 MA_API ma_result ma_resource_manager_data_stream_get_looping(const ma_resource_manager_data_stream* pDataStream, ma_bool32* pIsLooping);
@@ -692,6 +698,8 @@ MA_API ma_result ma_resource_manager_data_source_seek_to_pcm_frame(ma_resource_m
 MA_API ma_result ma_resource_manager_data_source_map(ma_resource_manager_data_source* pDataSource, void** ppFramesOut, ma_uint64* pFrameCount);
 MA_API ma_result ma_resource_manager_data_source_unmap(ma_resource_manager_data_source* pDataSource, ma_uint64 frameCount);
 MA_API ma_result ma_resource_manager_data_source_get_data_format(ma_resource_manager_data_source* pDataSource, ma_format* pFormat, ma_uint32* pChannels, ma_uint32* pSampleRate);
+MA_API ma_result ma_resource_manager_data_source_get_cursor_in_pcm_frames(ma_resource_manager_data_source* pDataSource, ma_uint64* pCursor);
+MA_API ma_result ma_resource_manager_data_source_get_length_in_pcm_frames(ma_resource_manager_data_source* pDataSource, ma_uint64* pLength);
 MA_API ma_result ma_resource_manager_data_source_result(const ma_resource_manager_data_source* pDataSource);
 MA_API ma_result ma_resource_manager_data_source_set_looping(ma_resource_manager_data_source* pDataSource, ma_bool32 isLooping);
 MA_API ma_result ma_resource_manager_data_source_get_looping(const ma_resource_manager_data_source* pDataSource, ma_bool32* pIsLooping);
@@ -2603,6 +2611,43 @@ MA_API ma_result ma_resource_manager_data_buffer_get_data_format(ma_resource_man
     return ma_data_source_get_data_format(ma_resource_manager_data_buffer_get_connector(pDataBuffer), pFormat, pChannels, pSampleRate);
 }
 
+MA_API ma_result ma_resource_manager_data_buffer_get_cursor_in_pcm_frames(ma_resource_manager_data_buffer* pDataBuffer, ma_uint64* pCursor)
+{
+    /* We cannot be using the data source after it's been uninitialized. */
+    MA_ASSERT(pDataBuffer->pNode->result != MA_UNAVAILABLE);
+
+    if (pDataBuffer == NULL || pCursor == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    *pCursor = pDataBuffer->cursor;
+
+    return MA_SUCCESS;
+}
+
+MA_API ma_result ma_resource_manager_data_buffer_get_length_in_pcm_frames(ma_resource_manager_data_buffer* pDataBuffer, ma_uint64* pLength)
+{
+    /* We cannot be using the data source after it's been uninitialized. */
+    MA_ASSERT(pDataBuffer->pNode->result != MA_UNAVAILABLE);
+
+    if (pDataBuffer == NULL || pLength == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    if (pDataBuffer->connectorType == ma_resource_manager_data_buffer_connector_unknown) {
+        return MA_BUSY; /* Still loading. */
+    }
+
+    if (pDataBuffer->connectorType == ma_resource_manager_data_buffer_connector_buffer) {
+        *pLength = pDataBuffer->pNode->data.decoded.frameCount;
+    } else {
+        /* TODO: This needs to change. This is too inefficient to be used generally because it may involve scanning the entire file. */
+        *pLength = ma_decoder_get_length_in_pcm_frames(&pDataBuffer->connector.decoder);
+    }
+
+    return MA_SUCCESS;
+}
+
 MA_API ma_result ma_resource_manager_data_buffer_result(const ma_resource_manager_data_buffer* pDataBuffer)
 {
     if (pDataBuffer == NULL) {
@@ -3122,6 +3167,9 @@ MA_API ma_result ma_resource_manager_data_stream_unmap(ma_resource_manager_data_
 
     pageSizeInFrames = ma_resource_manager_data_stream_get_page_size_in_frames(pDataStream);
 
+    /* The absolute cursor needs to be updated. */
+    pDataStream->absoluteCursor += frameCount;
+
     /* Here is where we need to check if we need to load a new page, and if so, post a job to load it. */
     newRelativeCursor = pDataStream->relativeCursor + (ma_uint32)frameCount;
 
@@ -3208,6 +3256,49 @@ MA_API ma_result ma_resource_manager_data_stream_get_data_format(ma_resource_man
     return ma_data_source_get_data_format(&pDataStream->decoder, pFormat, pChannels, pSampleRate);
 }
 
+MA_API ma_result ma_resource_manager_data_stream_get_cursor_in_pcm_frames(ma_resource_manager_data_stream* pDataStream, ma_uint64* pCursor)
+{
+    /* We cannot be using the data source after it's been uninitialized. */
+    MA_ASSERT(pDataStream->result != MA_UNAVAILABLE);
+
+    if (pDataStream == NULL || pCursor == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    if (pDataStream->result != MA_SUCCESS) {
+        return MA_INVALID_OPERATION;
+    }
+
+    *pCursor = pDataStream->absoluteCursor;
+
+    return MA_SUCCESS;
+}
+
+MA_API ma_result ma_resource_manager_data_stream_get_length_in_pcm_frames(ma_resource_manager_data_stream* pDataStream, ma_uint64* pLength)
+{
+    /* We cannot be using the data source after it's been uninitialized. */
+    MA_ASSERT(pDataStream->result != MA_UNAVAILABLE);
+
+    if (pDataStream == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    if (pDataStream->result != MA_SUCCESS) {
+        return MA_INVALID_OPERATION;
+    }
+
+    /*
+    We most definitely do not want to be calling ma_decoder_get_length_in_pcm_frames() directly. Instead we want to use a cached value that we
+    calculated when we initialized it on the job thread.
+    */
+    *pLength = pDataStream->totalLengthInPCMFrames;
+    if (*pLength == 0) {
+        return MA_NOT_IMPLEMENTED;  /* Some decoders may not have a known length. */
+    }
+
+    return MA_SUCCESS;
+}
+
 MA_API ma_result ma_resource_manager_data_stream_result(const ma_resource_manager_data_stream* pDataStream)
 {
     if (pDataStream == NULL) {
@@ -3375,6 +3466,32 @@ MA_API ma_result ma_resource_manager_data_source_get_data_format(ma_resource_man
     }
 }
 
+MA_API ma_result ma_resource_manager_data_source_get_cursor_in_pcm_frames(ma_resource_manager_data_source* pDataSource, ma_uint64* pCursor)
+{
+    if (pDataSource == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    if ((pDataSource->flags & MA_DATA_SOURCE_FLAG_STREAM) != 0) {
+        return ma_resource_manager_data_stream_get_cursor_in_pcm_frames(&pDataSource->stream, pCursor);
+    } else {
+        return ma_resource_manager_data_buffer_get_cursor_in_pcm_frames(&pDataSource->buffer, pCursor);
+    }
+}
+
+MA_API ma_result ma_resource_manager_data_source_get_length_in_pcm_frames(ma_resource_manager_data_source* pDataSource, ma_uint64* pLength)
+{
+    if (pDataSource == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    if ((pDataSource->flags & MA_DATA_SOURCE_FLAG_STREAM) != 0) {
+        return ma_resource_manager_data_stream_get_length_in_pcm_frames(&pDataSource->stream, pLength);
+    } else {
+        return ma_resource_manager_data_buffer_get_length_in_pcm_frames(&pDataSource->buffer, pLength);
+    }
+}
+
 MA_API ma_result ma_resource_manager_data_source_result(const ma_resource_manager_data_source* pDataSource)
 {
     if (pDataSource == NULL) {
@@ -3868,6 +3985,13 @@ static ma_result ma_resource_manager_process_job__load_data_stream(ma_resource_m
         goto done;
     }
 
+    /* Retrieve the total length of the file before marking the decoder are loaded. */
+    pDataStream->totalLengthInPCMFrames = ma_decoder_get_length_in_pcm_frames(&pDataStream->decoder);
+
+    /*
+    Only mark the decoder as initialized when the length of the decoder has been retrieved because that can possibly require a scan over the whole file
+    and we don't want to have another thread trying to access the decoder while it's scanning.
+    */
     pDataStream->isDecoderInitialized = MA_TRUE;
 
     /* We have the decoder so we can now initialize our page buffer. */