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dr_flac.h
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/*
FLAC audio decoder. Choice of public domain or MIT-0. See license statements at the end of this file.
dr_flac - v0.12.12 - 2020-04-30
David Reid - [email protected]
GitHub: https://github.com/mackron/dr_libs
*/
/*
RELEASE NOTES - v0.12.0
=======================
Version 0.12.0 has breaking API changes including changes to the existing API and the removal of deprecated APIs.
Improved Client-Defined Memory Allocation
-----------------------------------------
The main change with this release is the addition of a more flexible way of implementing custom memory allocation routines. The
existing system of DRFLAC_MALLOC, DRFLAC_REALLOC and DRFLAC_FREE are still in place and will be used by default when no custom
allocation callbacks are specified.
To use the new system, you pass in a pointer to a drflac_allocation_callbacks object to drflac_open() and family, like this:
void* my_malloc(size_t sz, void* pUserData)
{
return malloc(sz);
}
void* my_realloc(void* p, size_t sz, void* pUserData)
{
return realloc(p, sz);
}
void my_free(void* p, void* pUserData)
{
free(p);
}
...
drflac_allocation_callbacks allocationCallbacks;
allocationCallbacks.pUserData = &myData;
allocationCallbacks.onMalloc = my_malloc;
allocationCallbacks.onRealloc = my_realloc;
allocationCallbacks.onFree = my_free;
drflac* pFlac = drflac_open_file("my_file.flac", &allocationCallbacks);
The advantage of this new system is that it allows you to specify user data which will be passed in to the allocation routines.
Passing in null for the allocation callbacks object will cause dr_flac to use defaults which is the same as DRFLAC_MALLOC,
DRFLAC_REALLOC and DRFLAC_FREE and the equivalent of how it worked in previous versions.
Every API that opens a drflac object now takes this extra parameter. These include the following:
drflac_open()
drflac_open_relaxed()
drflac_open_with_metadata()
drflac_open_with_metadata_relaxed()
drflac_open_file()
drflac_open_file_with_metadata()
drflac_open_memory()
drflac_open_memory_with_metadata()
drflac_open_and_read_pcm_frames_s32()
drflac_open_and_read_pcm_frames_s16()
drflac_open_and_read_pcm_frames_f32()
drflac_open_file_and_read_pcm_frames_s32()
drflac_open_file_and_read_pcm_frames_s16()
drflac_open_file_and_read_pcm_frames_f32()
drflac_open_memory_and_read_pcm_frames_s32()
drflac_open_memory_and_read_pcm_frames_s16()
drflac_open_memory_and_read_pcm_frames_f32()
Optimizations
-------------
Seeking performance has been greatly improved. A new binary search based seeking algorithm has been introduced which significantly
improves performance over the brute force method which was used when no seek table was present. Seek table based seeking also takes
advantage of the new binary search seeking system to further improve performance there as well. Note that this depends on CRC which
means it will be disabled when DR_FLAC_NO_CRC is used.
The SSE4.1 pipeline has been cleaned up and optimized. You should see some improvements with decoding speed of 24-bit files in
particular. 16-bit streams should also see some improvement.
drflac_read_pcm_frames_s16() has been optimized. Previously this sat on top of drflac_read_pcm_frames_s32() and performed it's s32
to s16 conversion in a second pass. This is now all done in a single pass. This includes SSE2 and ARM NEON optimized paths.
A minor optimization has been implemented for drflac_read_pcm_frames_s32(). This will now use an SSE2 optimized pipeline for stereo
channel reconstruction which is the last part of the decoding process.
The ARM build has seen a few improvements. The CLZ (count leading zeroes) and REV (byte swap) instructions are now used when
compiling with GCC and Clang which is achieved using inline assembly. The CLZ instruction requires ARM architecture version 5 at
compile time and the REV instruction requires ARM architecture version 6.
An ARM NEON optimized pipeline has been implemented. To enable this you'll need to add -mfpu=neon to the command line when compiling.
Removed APIs
------------
The following APIs were deprecated in version 0.11.0 and have been completely removed in version 0.12.0:
drflac_read_s32() -> drflac_read_pcm_frames_s32()
drflac_read_s16() -> drflac_read_pcm_frames_s16()
drflac_read_f32() -> drflac_read_pcm_frames_f32()
drflac_seek_to_sample() -> drflac_seek_to_pcm_frame()
drflac_open_and_decode_s32() -> drflac_open_and_read_pcm_frames_s32()
drflac_open_and_decode_s16() -> drflac_open_and_read_pcm_frames_s16()
drflac_open_and_decode_f32() -> drflac_open_and_read_pcm_frames_f32()
drflac_open_and_decode_file_s32() -> drflac_open_file_and_read_pcm_frames_s32()
drflac_open_and_decode_file_s16() -> drflac_open_file_and_read_pcm_frames_s16()
drflac_open_and_decode_file_f32() -> drflac_open_file_and_read_pcm_frames_f32()
drflac_open_and_decode_memory_s32() -> drflac_open_memory_and_read_pcm_frames_s32()
drflac_open_and_decode_memory_s16() -> drflac_open_memory_and_read_pcm_frames_s16()
drflac_open_and_decode_memory_f32() -> drflac_open_memroy_and_read_pcm_frames_f32()
Prior versions of dr_flac operated on a per-sample basis whereas now it operates on PCM frames. The removed APIs all relate
to the old per-sample APIs. You now need to use the "pcm_frame" versions.
*/
/*
Introduction
============
dr_flac is a single file library. To use it, do something like the following in one .c file.
```c
#define DR_FLAC_IMPLEMENTATION
#include "dr_flac.h"
```
You can then #include this file in other parts of the program as you would with any other header file. To decode audio data, do something like the following:
```c
drflac* pFlac = drflac_open_file("MySong.flac", NULL);
if (pFlac == NULL) {
// Failed to open FLAC file
}
drflac_int32* pSamples = malloc(pFlac->totalPCMFrameCount * pFlac->channels * sizeof(drflac_int32));
drflac_uint64 numberOfInterleavedSamplesActuallyRead = drflac_read_pcm_frames_s32(pFlac, pFlac->totalPCMFrameCount, pSamples);
```
The drflac object represents the decoder. It is a transparent type so all the information you need, such as the number of channels and the bits per sample,
should be directly accessible - just make sure you don't change their values. Samples are always output as interleaved signed 32-bit PCM. In the example above
a native FLAC stream was opened, however dr_flac has seamless support for Ogg encapsulated FLAC streams as well.
You do not need to decode the entire stream in one go - you just specify how many samples you'd like at any given time and the decoder will give you as many
samples as it can, up to the amount requested. Later on when you need the next batch of samples, just call it again. Example:
```c
while (drflac_read_pcm_frames_s32(pFlac, chunkSizeInPCMFrames, pChunkSamples) > 0) {
do_something();
}
```
You can seek to a specific PCM frame with `drflac_seek_to_pcm_frame()`.
If you just want to quickly decode an entire FLAC file in one go you can do something like this:
```c
unsigned int channels;
unsigned int sampleRate;
drflac_uint64 totalPCMFrameCount;
drflac_int32* pSampleData = drflac_open_file_and_read_pcm_frames_s32("MySong.flac", &channels, &sampleRate, &totalPCMFrameCount, NULL);
if (pSampleData == NULL) {
// Failed to open and decode FLAC file.
}
...
drflac_free(pSampleData);
```
You can read samples as signed 16-bit integer and 32-bit floating-point PCM with the *_s16() and *_f32() family of APIs respectively, but note that these
should be considered lossy.
If you need access to metadata (album art, etc.), use `drflac_open_with_metadata()`, `drflac_open_file_with_metdata()` or `drflac_open_memory_with_metadata()`.
The rationale for keeping these APIs separate is that they're slightly slower than the normal versions and also just a little bit harder to use. dr_flac
reports metadata to the application through the use of a callback, and every metadata block is reported before `drflac_open_with_metdata()` returns.
The main opening APIs (`drflac_open()`, etc.) will fail if the header is not present. The presents a problem in certain scenarios such as broadcast style
streams or internet radio where the header may not be present because the user has started playback mid-stream. To handle this, use the relaxed APIs:
`drflac_open_relaxed()`
`drflac_open_with_metadata_relaxed()`
It is not recommended to use these APIs for file based streams because a missing header would usually indicate a corrupt or perverse file. In addition, these
APIs can take a long time to initialize because they may need to spend a lot of time finding the first frame.
Build Options
=============
#define these options before including this file.
#define DR_FLAC_NO_STDIO
Disable `drflac_open_file()` and family.
#define DR_FLAC_NO_OGG
Disables support for Ogg/FLAC streams.
#define DR_FLAC_BUFFER_SIZE <number>
Defines the size of the internal buffer to store data from onRead(). This buffer is used to reduce the number of calls back to the client for more data.
Larger values means more memory, but better performance. My tests show diminishing returns after about 4KB (which is the default). Consider reducing this if
you have a very efficient implementation of onRead(), or increase it if it's very inefficient. Must be a multiple of 8.
#define DR_FLAC_NO_CRC
Disables CRC checks. This will offer a performance boost when CRC is unnecessary. This will disable binary search seeking. When seeking, the seek table will
be used if available. Otherwise the seek will be performed using brute force.
#define DR_FLAC_NO_SIMD
Disables SIMD optimizations (SSE on x86/x64 architectures, NEON on ARM architectures). Use this if you are having compatibility issues with your compiler.
Notes
=====
- dr_flac does not support changing the sample rate nor channel count mid stream.
- dr_flac is not thread-safe, but its APIs can be called from any thread so long as you do your own synchronization.
- When using Ogg encapsulation, a corrupted metadata block will result in `drflac_open_with_metadata()` and `drflac_open()` returning inconsistent samples due
to differences in corrupted stream recorvery logic between the two APIs.
*/
#ifndef dr_flac_h
#define dr_flac_h
#ifdef __cplusplus
extern "C" {
#endif
#include <stddef.h> /* For size_t. */
/* Sized types. Prefer built-in types. Fall back to stdint. */
#ifdef _MSC_VER
#if defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wlanguage-extension-token"
#pragma GCC diagnostic ignored "-Wlong-long"
#pragma GCC diagnostic ignored "-Wc++11-long-long"
#endif
typedef signed __int8 drflac_int8;
typedef unsigned __int8 drflac_uint8;
typedef signed __int16 drflac_int16;
typedef unsigned __int16 drflac_uint16;
typedef signed __int32 drflac_int32;
typedef unsigned __int32 drflac_uint32;
typedef signed __int64 drflac_int64;
typedef unsigned __int64 drflac_uint64;
#if defined(__clang__)
#pragma GCC diagnostic pop
#endif
#else
#include <stdint.h>
typedef int8_t drflac_int8;
typedef uint8_t drflac_uint8;
typedef int16_t drflac_int16;
typedef uint16_t drflac_uint16;
typedef int32_t drflac_int32;
typedef uint32_t drflac_uint32;
typedef int64_t drflac_int64;
typedef uint64_t drflac_uint64;
#endif
typedef drflac_uint8 drflac_bool8;
typedef drflac_uint32 drflac_bool32;
#define DRFLAC_TRUE 1
#define DRFLAC_FALSE 0
#if !defined(DRFLAC_API)
#if defined(DRFLAC_DLL)
#if defined(_WIN32)
#define DRFLAC_DLL_IMPORT __declspec(dllimport)
#define DRFLAC_DLL_EXPORT __declspec(dllexport)
#define DRFLAC_DLL_PRIVATE static
#else
#if defined(__GNUC__) && __GNUC__ >= 4
#define DRFLAC_DLL_IMPORT __attribute__((visibility("default")))
#define DRFLAC_DLL_EXPORT __attribute__((visibility("default")))
#define DRFLAC_DLL_PRIVATE __attribute__((visibility("hidden")))
#else
#define DRFLAC_DLL_IMPORT
#define DRFLAC_DLL_EXPORT
#define DRFLAC_DLL_PRIVATE static
#endif
#endif
#if defined(DR_FLAC_IMPLEMENTATION) || defined(DRFLAC_IMPLEMENTATION)
#define DRFLAC_API DRFLAC_DLL_EXPORT
#else
#define DRFLAC_API DRFLAC_DLL_IMPORT
#endif
#define DRFLAC_PRIVATE DRFLAC_DLL_PRIVATE
#else
#define DRFLAC_API extern
#define DRFLAC_PRIVATE static
#endif
#endif
#if defined(_MSC_VER) && _MSC_VER >= 1700 /* Visual Studio 2012 */
#define DRFLAC_DEPRECATED __declspec(deprecated)
#elif (defined(__GNUC__) && __GNUC__ >= 4) /* GCC 4 */
#define DRFLAC_DEPRECATED __attribute__((deprecated))
#elif defined(__has_feature) /* Clang */
#if __has_feature(attribute_deprecated)
#define DRFLAC_DEPRECATED __attribute__((deprecated))
#else
#define DRFLAC_DEPRECATED
#endif
#else
#define DRFLAC_DEPRECATED
#endif
/*
As data is read from the client it is placed into an internal buffer for fast access. This controls the size of that buffer. Larger values means more speed,
but also more memory. In my testing there is diminishing returns after about 4KB, but you can fiddle with this to suit your own needs. Must be a multiple of 8.
*/
#ifndef DR_FLAC_BUFFER_SIZE
#define DR_FLAC_BUFFER_SIZE 4096
#endif
/* Check if we can enable 64-bit optimizations. */
#if defined(_WIN64) || defined(_LP64) || defined(__LP64__)
#define DRFLAC_64BIT
#endif
#ifdef DRFLAC_64BIT
typedef drflac_uint64 drflac_cache_t;
#else
typedef drflac_uint32 drflac_cache_t;
#endif
/* The various metadata block types. */
#define DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO 0
#define DRFLAC_METADATA_BLOCK_TYPE_PADDING 1
#define DRFLAC_METADATA_BLOCK_TYPE_APPLICATION 2
#define DRFLAC_METADATA_BLOCK_TYPE_SEEKTABLE 3
#define DRFLAC_METADATA_BLOCK_TYPE_VORBIS_COMMENT 4
#define DRFLAC_METADATA_BLOCK_TYPE_CUESHEET 5
#define DRFLAC_METADATA_BLOCK_TYPE_PICTURE 6
#define DRFLAC_METADATA_BLOCK_TYPE_INVALID 127
/* The various picture types specified in the PICTURE block. */
#define DRFLAC_PICTURE_TYPE_OTHER 0
#define DRFLAC_PICTURE_TYPE_FILE_ICON 1
#define DRFLAC_PICTURE_TYPE_OTHER_FILE_ICON 2
#define DRFLAC_PICTURE_TYPE_COVER_FRONT 3
#define DRFLAC_PICTURE_TYPE_COVER_BACK 4
#define DRFLAC_PICTURE_TYPE_LEAFLET_PAGE 5
#define DRFLAC_PICTURE_TYPE_MEDIA 6
#define DRFLAC_PICTURE_TYPE_LEAD_ARTIST 7
#define DRFLAC_PICTURE_TYPE_ARTIST 8
#define DRFLAC_PICTURE_TYPE_CONDUCTOR 9
#define DRFLAC_PICTURE_TYPE_BAND 10
#define DRFLAC_PICTURE_TYPE_COMPOSER 11
#define DRFLAC_PICTURE_TYPE_LYRICIST 12
#define DRFLAC_PICTURE_TYPE_RECORDING_LOCATION 13
#define DRFLAC_PICTURE_TYPE_DURING_RECORDING 14
#define DRFLAC_PICTURE_TYPE_DURING_PERFORMANCE 15
#define DRFLAC_PICTURE_TYPE_SCREEN_CAPTURE 16
#define DRFLAC_PICTURE_TYPE_BRIGHT_COLORED_FISH 17
#define DRFLAC_PICTURE_TYPE_ILLUSTRATION 18
#define DRFLAC_PICTURE_TYPE_BAND_LOGOTYPE 19
#define DRFLAC_PICTURE_TYPE_PUBLISHER_LOGOTYPE 20
typedef enum
{
drflac_container_native,
drflac_container_ogg,
drflac_container_unknown
} drflac_container;
typedef enum
{
drflac_seek_origin_start,
drflac_seek_origin_current
} drflac_seek_origin;
/* Packing is important on this structure because we map this directly to the raw data within the SEEKTABLE metadata block. */
#pragma pack(2)
typedef struct
{
drflac_uint64 firstPCMFrame;
drflac_uint64 flacFrameOffset; /* The offset from the first byte of the header of the first frame. */
drflac_uint16 pcmFrameCount;
} drflac_seekpoint;
#pragma pack()
typedef struct
{
drflac_uint16 minBlockSizeInPCMFrames;
drflac_uint16 maxBlockSizeInPCMFrames;
drflac_uint32 minFrameSizeInPCMFrames;
drflac_uint32 maxFrameSizeInPCMFrames;
drflac_uint32 sampleRate;
drflac_uint8 channels;
drflac_uint8 bitsPerSample;
drflac_uint64 totalPCMFrameCount;
drflac_uint8 md5[16];
} drflac_streaminfo;
typedef struct
{
/* The metadata type. Use this to know how to interpret the data below. */
drflac_uint32 type;
/*
A pointer to the raw data. This points to a temporary buffer so don't hold on to it. It's best to
not modify the contents of this buffer. Use the structures below for more meaningful and structured
information about the metadata. It's possible for this to be null.
*/
const void* pRawData;
/* The size in bytes of the block and the buffer pointed to by pRawData if it's non-NULL. */
drflac_uint32 rawDataSize;
union
{
drflac_streaminfo streaminfo;
struct
{
int unused;
} padding;
struct
{
drflac_uint32 id;
const void* pData;
drflac_uint32 dataSize;
} application;
struct
{
drflac_uint32 seekpointCount;
const drflac_seekpoint* pSeekpoints;
} seektable;
struct
{
drflac_uint32 vendorLength;
const char* vendor;
drflac_uint32 commentCount;
const void* pComments;
} vorbis_comment;
struct
{
char catalog[128];
drflac_uint64 leadInSampleCount;
drflac_bool32 isCD;
drflac_uint8 trackCount;
const void* pTrackData;
} cuesheet;
struct
{
drflac_uint32 type;
drflac_uint32 mimeLength;
const char* mime;
drflac_uint32 descriptionLength;
const char* description;
drflac_uint32 width;
drflac_uint32 height;
drflac_uint32 colorDepth;
drflac_uint32 indexColorCount;
drflac_uint32 pictureDataSize;
const drflac_uint8* pPictureData;
} picture;
} data;
} drflac_metadata;
/*
Callback for when data needs to be read from the client.
Parameters
----------
pUserData (in)
The user data that was passed to drflac_open() and family.
pBufferOut (out)
The output buffer.
bytesToRead (in)
The number of bytes to read.
Return Value
------------
The number of bytes actually read.
Remarks
-------
A return value of less than bytesToRead indicates the end of the stream. Do _not_ return from this callback until either the entire bytesToRead is filled or
you have reached the end of the stream.
*/
typedef size_t (* drflac_read_proc)(void* pUserData, void* pBufferOut, size_t bytesToRead);
/*
Callback for when data needs to be seeked.
Parameters
----------
pUserData (in)
The user data that was passed to drflac_open() and family.
offset (in)
The number of bytes to move, relative to the origin. Will never be negative.
origin (in)
The origin of the seek - the current position or the start of the stream.
Return Value
------------
Whether or not the seek was successful.
Remarks
-------
The offset will never be negative. Whether or not it is relative to the beginning or current position is determined by the "origin" parameter which will be
either drflac_seek_origin_start or drflac_seek_origin_current.
When seeking to a PCM frame using drflac_seek_to_pcm_frame(), dr_flac may call this with an offset beyond the end of the FLAC stream. This needs to be detected
and handled by returning DRFLAC_FALSE.
*/
typedef drflac_bool32 (* drflac_seek_proc)(void* pUserData, int offset, drflac_seek_origin origin);
/*
Callback for when a metadata block is read.
Parameters
----------
pUserData (in)
The user data that was passed to drflac_open() and family.
pMetadata (in)
A pointer to a structure containing the data of the metadata block.
Remarks
-------
Use pMetadata->type to determine which metadata block is being handled and how to read the data.
*/
typedef void (* drflac_meta_proc)(void* pUserData, drflac_metadata* pMetadata);
typedef struct
{
void* pUserData;
void* (* onMalloc)(size_t sz, void* pUserData);
void* (* onRealloc)(void* p, size_t sz, void* pUserData);
void (* onFree)(void* p, void* pUserData);
} drflac_allocation_callbacks;
/* Structure for internal use. Only used for decoders opened with drflac_open_memory. */
typedef struct
{
const drflac_uint8* data;
size_t dataSize;
size_t currentReadPos;
} drflac__memory_stream;
/* Structure for internal use. Used for bit streaming. */
typedef struct
{
/* The function to call when more data needs to be read. */
drflac_read_proc onRead;
/* The function to call when the current read position needs to be moved. */
drflac_seek_proc onSeek;
/* The user data to pass around to onRead and onSeek. */
void* pUserData;
/*
The number of unaligned bytes in the L2 cache. This will always be 0 until the end of the stream is hit. At the end of the
stream there will be a number of bytes that don't cleanly fit in an L1 cache line, so we use this variable to know whether
or not the bistreamer needs to run on a slower path to read those last bytes. This will never be more than sizeof(drflac_cache_t).
*/
size_t unalignedByteCount;
/* The content of the unaligned bytes. */
drflac_cache_t unalignedCache;
/* The index of the next valid cache line in the "L2" cache. */
drflac_uint32 nextL2Line;
/* The number of bits that have been consumed by the cache. This is used to determine how many valid bits are remaining. */
drflac_uint32 consumedBits;
/*
The cached data which was most recently read from the client. There are two levels of cache. Data flows as such:
Client -> L2 -> L1. The L2 -> L1 movement is aligned and runs on a fast path in just a few instructions.
*/
drflac_cache_t cacheL2[DR_FLAC_BUFFER_SIZE/sizeof(drflac_cache_t)];
drflac_cache_t cache;
/*
CRC-16. This is updated whenever bits are read from the bit stream. Manually set this to 0 to reset the CRC. For FLAC, this
is reset to 0 at the beginning of each frame.
*/
drflac_uint16 crc16;
drflac_cache_t crc16Cache; /* A cache for optimizing CRC calculations. This is filled when when the L1 cache is reloaded. */
drflac_uint32 crc16CacheIgnoredBytes; /* The number of bytes to ignore when updating the CRC-16 from the CRC-16 cache. */
} drflac_bs;
typedef struct
{
/* The type of the subframe: SUBFRAME_CONSTANT, SUBFRAME_VERBATIM, SUBFRAME_FIXED or SUBFRAME_LPC. */
drflac_uint8 subframeType;
/* The number of wasted bits per sample as specified by the sub-frame header. */
drflac_uint8 wastedBitsPerSample;
/* The order to use for the prediction stage for SUBFRAME_FIXED and SUBFRAME_LPC. */
drflac_uint8 lpcOrder;
/* A pointer to the buffer containing the decoded samples in the subframe. This pointer is an offset from drflac::pExtraData. */
drflac_int32* pSamplesS32;
} drflac_subframe;
typedef struct
{
/*
If the stream uses variable block sizes, this will be set to the index of the first PCM frame. If fixed block sizes are used, this will
always be set to 0. This is 64-bit because the decoded PCM frame number will be 36 bits.
*/
drflac_uint64 pcmFrameNumber;
/*
If the stream uses fixed block sizes, this will be set to the frame number. If variable block sizes are used, this will always be 0. This
is 32-bit because in fixed block sizes, the maximum frame number will be 31 bits.
*/
drflac_uint32 flacFrameNumber;
/* The sample rate of this frame. */
drflac_uint32 sampleRate;
/* The number of PCM frames in each sub-frame within this frame. */
drflac_uint16 blockSizeInPCMFrames;
/*
The channel assignment of this frame. This is not always set to the channel count. If interchannel decorrelation is being used this
will be set to DRFLAC_CHANNEL_ASSIGNMENT_LEFT_SIDE, DRFLAC_CHANNEL_ASSIGNMENT_RIGHT_SIDE or DRFLAC_CHANNEL_ASSIGNMENT_MID_SIDE.
*/
drflac_uint8 channelAssignment;
/* The number of bits per sample within this frame. */
drflac_uint8 bitsPerSample;
/* The frame's CRC. */
drflac_uint8 crc8;
} drflac_frame_header;
typedef struct
{
/* The header. */
drflac_frame_header header;
/*
The number of PCM frames left to be read in this FLAC frame. This is initially set to the block size. As PCM frames are read,
this will be decremented. When it reaches 0, the decoder will see this frame as fully consumed and load the next frame.
*/
drflac_uint32 pcmFramesRemaining;
/* The list of sub-frames within the frame. There is one sub-frame for each channel, and there's a maximum of 8 channels. */
drflac_subframe subframes[8];
} drflac_frame;
typedef struct
{
/* The function to call when a metadata block is read. */
drflac_meta_proc onMeta;
/* The user data posted to the metadata callback function. */
void* pUserDataMD;
/* Memory allocation callbacks. */
drflac_allocation_callbacks allocationCallbacks;
/* The sample rate. Will be set to something like 44100. */
drflac_uint32 sampleRate;
/*
The number of channels. This will be set to 1 for monaural streams, 2 for stereo, etc. Maximum 8. This is set based on the
value specified in the STREAMINFO block.
*/
drflac_uint8 channels;
/* The bits per sample. Will be set to something like 16, 24, etc. */
drflac_uint8 bitsPerSample;
/* The maximum block size, in samples. This number represents the number of samples in each channel (not combined). */
drflac_uint16 maxBlockSizeInPCMFrames;
/*
The total number of PCM Frames making up the stream. Can be 0 in which case it's still a valid stream, but just means
the total PCM frame count is unknown. Likely the case with streams like internet radio.
*/
drflac_uint64 totalPCMFrameCount;
/* The container type. This is set based on whether or not the decoder was opened from a native or Ogg stream. */
drflac_container container;
/* The number of seekpoints in the seektable. */
drflac_uint32 seekpointCount;
/* Information about the frame the decoder is currently sitting on. */
drflac_frame currentFLACFrame;
/* The index of the PCM frame the decoder is currently sitting on. This is only used for seeking. */
drflac_uint64 currentPCMFrame;
/* The position of the first FLAC frame in the stream. This is only ever used for seeking. */
drflac_uint64 firstFLACFramePosInBytes;
/* A hack to avoid a malloc() when opening a decoder with drflac_open_memory(). */
drflac__memory_stream memoryStream;
/* A pointer to the decoded sample data. This is an offset of pExtraData. */
drflac_int32* pDecodedSamples;
/* A pointer to the seek table. This is an offset of pExtraData, or NULL if there is no seek table. */
drflac_seekpoint* pSeekpoints;
/* Internal use only. Only used with Ogg containers. Points to a drflac_oggbs object. This is an offset of pExtraData. */
void* _oggbs;
/* Internal use only. Used for profiling and testing different seeking modes. */
drflac_bool32 _noSeekTableSeek : 1;
drflac_bool32 _noBinarySearchSeek : 1;
drflac_bool32 _noBruteForceSeek : 1;
/* The bit streamer. The raw FLAC data is fed through this object. */
drflac_bs bs;
/* Variable length extra data. We attach this to the end of the object so we can avoid unnecessary mallocs. */
drflac_uint8 pExtraData[1];
} drflac;
/*
Opens a FLAC decoder.
Parameters
----------
onRead (in)
The function to call when data needs to be read from the client.
onSeek (in)
The function to call when the read position of the client data needs to move.
pUserData (in, optional)
A pointer to application defined data that will be passed to onRead and onSeek.
pAllocationCallbacks (in, optional)
A pointer to application defined callbacks for managing memory allocations.
Return Value
------------
Returns a pointer to an object representing the decoder.
Remarks
-------
Close the decoder with `drflac_close()`.
`pAllocationCallbacks` can be NULL in which case it will use `DRFLAC_MALLOC`, `DRFLAC_REALLOC` and `DRFLAC_FREE`.
This function will automatically detect whether or not you are attempting to open a native or Ogg encapsulated FLAC, both of which should work seamlessly
without any manual intervention. Ogg encapsulation also works with multiplexed streams which basically means it can play FLAC encoded audio tracks in videos.
This is the lowest level function for opening a FLAC stream. You can also use `drflac_open_file()` and `drflac_open_memory()` to open the stream from a file or
from a block of memory respectively.
The STREAMINFO block must be present for this to succeed. Use `drflac_open_relaxed()` to open a FLAC stream where the header may not be present.
Seek Also
---------
drflac_open_file()
drflac_open_memory()
drflac_open_with_metadata()
drflac_close()
*/
DRFLAC_API drflac* drflac_open(drflac_read_proc onRead, drflac_seek_proc onSeek, void* pUserData, const drflac_allocation_callbacks* pAllocationCallbacks);
/*
Opens a FLAC stream with relaxed validation of the header block.
Parameters
----------
onRead (in)
The function to call when data needs to be read from the client.
onSeek (in)
The function to call when the read position of the client data needs to move.
container (in)
Whether or not the FLAC stream is encapsulated using standard FLAC encapsulation or Ogg encapsulation.
pUserData (in, optional)
A pointer to application defined data that will be passed to onRead and onSeek.
pAllocationCallbacks (in, optional)
A pointer to application defined callbacks for managing memory allocations.
Return Value
------------
A pointer to an object representing the decoder.
Remarks
-------
The same as drflac_open(), except attempts to open the stream even when a header block is not present.
Because the header is not necessarily available, the caller must explicitly define the container (Native or Ogg). Do not set this to `drflac_container_unknown`
as that is for internal use only.
Opening in relaxed mode will continue reading data from onRead until it finds a valid frame. If a frame is never found it will continue forever. To abort,
force your `onRead` callback to return 0, which dr_flac will use as an indicator that the end of the stream was found.
*/
DRFLAC_API drflac* drflac_open_relaxed(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_container container, void* pUserData, const drflac_allocation_callbacks* pAllocationCallbacks);
/*
Opens a FLAC decoder and notifies the caller of the metadata chunks (album art, etc.).
Parameters
----------
onRead (in)
The function to call when data needs to be read from the client.
onSeek (in)
The function to call when the read position of the client data needs to move.
onMeta (in)
The function to call for every metadata block.
pUserData (in, optional)
A pointer to application defined data that will be passed to onRead, onSeek and onMeta.
pAllocationCallbacks (in, optional)
A pointer to application defined callbacks for managing memory allocations.
Return Value
------------
A pointer to an object representing the decoder.
Remarks
-------
Close the decoder with `drflac_close()`.
`pAllocationCallbacks` can be NULL in which case it will use `DRFLAC_MALLOC`, `DRFLAC_REALLOC` and `DRFLAC_FREE`.
This is slower than `drflac_open()`, so avoid this one if you don't need metadata. Internally, this will allocate and free memory on the heap for every
metadata block except for STREAMINFO and PADDING blocks.
The caller is notified of the metadata via the `onMeta` callback. All metadata blocks will be handled before the function returns.
The STREAMINFO block must be present for this to succeed. Use `drflac_open_with_metadata_relaxed()` to open a FLAC stream where the header may not be present.
Note that this will behave inconsistently with `drflac_open()` if the stream is an Ogg encapsulated stream and a metadata block is corrupted. This is due to
the way the Ogg stream recovers from corrupted pages. When `drflac_open_with_metadata()` is being used, the open routine will try to read the contents of the
metadata block, whereas `drflac_open()` will simply seek past it (for the sake of efficiency). This inconsistency can result in different samples being
returned depending on whether or not the stream is being opened with metadata.
Seek Also
---------
drflac_open_file_with_metadata()
drflac_open_memory_with_metadata()
drflac_open()
drflac_close()
*/
DRFLAC_API drflac* drflac_open_with_metadata(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, void* pUserData, const drflac_allocation_callbacks* pAllocationCallbacks);
/*
The same as drflac_open_with_metadata(), except attempts to open the stream even when a header block is not present.
See Also
--------
drflac_open_with_metadata()
drflac_open_relaxed()
*/
DRFLAC_API drflac* drflac_open_with_metadata_relaxed(drflac_read_proc onRead, drflac_seek_proc onSeek, drflac_meta_proc onMeta, drflac_container container, void* pUserData, const drflac_allocation_callbacks* pAllocationCallbacks);
/*
Closes the given FLAC decoder.
Parameters
----------
pFlac (in)
The decoder to close.
Remarks
-------
This will destroy the decoder object.
See Also
--------
drflac_open()
drflac_open_with_metadata()
drflac_open_file()
drflac_open_file_w()
drflac_open_file_with_metadata()
drflac_open_file_with_metadata_w()
drflac_open_memory()
drflac_open_memory_with_metadata()
*/
DRFLAC_API void drflac_close(drflac* pFlac);
/*
Reads sample data from the given FLAC decoder, output as interleaved signed 32-bit PCM.
Parameters
----------
pFlac (in)
The decoder.
framesToRead (in)
The number of PCM frames to read.
pBufferOut (out, optional)
A pointer to the buffer that will receive the decoded samples.
Return Value
------------
Returns the number of PCM frames actually read. If the return value is less than `framesToRead` it has reached the end.
Remarks
-------
pBufferOut can be null, in which case the call will act as a seek, and the return value will be the number of frames seeked.
*/
DRFLAC_API drflac_uint64 drflac_read_pcm_frames_s32(drflac* pFlac, drflac_uint64 framesToRead, drflac_int32* pBufferOut);
/*
Reads sample data from the given FLAC decoder, output as interleaved signed 16-bit PCM.
Parameters
----------
pFlac (in)
The decoder.
framesToRead (in)
The number of PCM frames to read.
pBufferOut (out, optional)
A pointer to the buffer that will receive the decoded samples.
Return Value
------------
Returns the number of PCM frames actually read. If the return value is less than `framesToRead` it has reached the end.
Remarks
-------
pBufferOut can be null, in which case the call will act as a seek, and the return value will be the number of frames seeked.
Note that this is lossy for streams where the bits per sample is larger than 16.
*/
DRFLAC_API drflac_uint64 drflac_read_pcm_frames_s16(drflac* pFlac, drflac_uint64 framesToRead, drflac_int16* pBufferOut);
/*
Reads sample data from the given FLAC decoder, output as interleaved 32-bit floating point PCM.
Parameters
----------
pFlac (in)
The decoder.
framesToRead (in)
The number of PCM frames to read.