stb_vorbis.h

//
//  stb_vorbis.h
//  oggdecode
//
//  Created by Michael Grierson on 04/04/2012.
//  Copyright (c) 2012 goldsmiths college. All rights reserved.
//



//////////////////////////////////////////////////////////////////////////////
//
//  HEADER BEGINS HERE
//

#ifndef STB_VORBIS_INCLUDE_STB_VORBIS_H
#define STB_VORBIS_INCLUDE_STB_VORBIS_H

#if defined(STB_VORBIS_NO_CRT) && !defined(STB_VORBIS_NO_STDIO)
#define STB_VORBIS_NO_STDIO 1
#endif

#ifndef STB_VORBIS_NO_STDIO
#include <stdio.h>
#endif

#ifdef __cplusplus
extern "C" {
#endif
    
    ///////////   THREAD SAFETY
    
    // Individual stb_vorbis* handles are not thread-safe; you cannot decode from
    // them from multiple threads at the same time. However, you can have multiple
    // stb_vorbis* handles and decode from them independently in multiple thrads.
    
    
    ///////////   MEMORY ALLOCATION
    
    // normally stb_vorbis uses malloc() to allocate memory at startup,
    // and alloca() to allocate temporary memory during a frame on the
    // stack. (Memory consumption will depend on the amount of setup
    // data in the file and how you set the compile flags for speed
    // vs. size. In my test files the maximal-size usage is ~150KB.)
    //
    // You can modify the wrapper functions in the source (setup_malloc,
    // setup_temp_malloc, temp_malloc) to change this behavior, or you
    // can use a simpler allocation model: you pass in a buffer from
    // which stb_vorbis will allocate _all_ its memory (including the
    // temp memory). "open" may fail with a VORBIS_outofmem if you
    // do not pass in enough data; there is no way to determine how
    // much you do need except to succeed (at which point you can
    // query get_info to find the exact amount required. yes I know
    // this is lame).
    //
    // If you pass in a non-NULL buffer of the type below, allocation
    // will occur from it as described above. Otherwise just pass NULL
    // to use malloc()/alloca()
    
    typedef struct
    {
        char *alloc_buffer;
        int   alloc_buffer_length_in_bytes;
    } stb_vorbis_alloc;
    
    
    ///////////   FUNCTIONS USEABLE WITH ALL INPUT MODES
    
    typedef struct stb_vorbis stb_vorbis;
    
    typedef struct
    {
        unsigned int sample_rate;
        int channels;
        
        unsigned int setup_memory_required;
        unsigned int setup_temp_memory_required;
        unsigned int temp_memory_required;
        
        int max_frame_size;
    } stb_vorbis_info;
    
    // get general information about the file
    extern stb_vorbis_info stb_vorbis_get_info(stb_vorbis *f);
    
    // get the last error detected (clears it, too)
    extern int stb_vorbis_get_error(stb_vorbis *f);
    
    // close an ogg vorbis file and free all memory in use
    extern void stb_vorbis_close(stb_vorbis *f);
    
    // this function returns the offset (in samples) from the beginning of the
    // file that will be returned by the next decode, if it is known, or -1
    // otherwise. after a flush_pushdata() call, this may take a while before
    // it becomes valid again.
    // NOT WORKING YET after a seek with PULLDATA API
    extern int stb_vorbis_get_sample_offset(stb_vorbis *f);
    
    // returns the current seek point within the file, or offset from the beginning
    // of the memory buffer. In pushdata mode it returns 0.
    extern unsigned int stb_vorbis_get_file_offset(stb_vorbis *f);
    
    ///////////   PUSHDATA API
    
#ifndef STB_VORBIS_NO_PUSHDATA_API
    
    // this API allows you to get blocks of data from any source and hand
    // them to stb_vorbis. you have to buffer them; stb_vorbis will tell
    // you how much it used, and you have to give it the rest next time;
    // and stb_vorbis may not have enough data to work with and you will
    // need to give it the same data again PLUS more. Note that the Vorbis
    // specification does not bound the size of an individual frame.
    
    extern stb_vorbis *stb_vorbis_open_pushdata(
                                                unsigned char *datablock, int datablock_length_in_bytes,
                                                int *datablock_memory_consumed_in_bytes,
                                                int *error,
                                                stb_vorbis_alloc *alloc_buffer);
    // create a vorbis decoder by passing in the initial data block containing
    //    the ogg&vorbis headers (you don't need to do parse them, just provide
    //    the first N bytes of the file--you're told if it's not enough, see below)
    // on success, returns an stb_vorbis *, does not set error, returns the amount of
    //    data parsed/consumed on this call in *datablock_memory_consumed_in_bytes;
    // on failure, returns NULL on error and sets *error, does not change *datablock_memory_consumed
    // if returns NULL and *error is VORBIS_need_more_data, then the input block was
    //       incomplete and you need to pass in a larger block from the start of the file
    
    extern int stb_vorbis_decode_frame_pushdata(
                                                stb_vorbis *f, unsigned char *datablock, int datablock_length_in_bytes,
                                                int *channels,             // place to write number of float * buffers
                                                float ***output,           // place to write float ** array of float * buffers
                                                int *samples               // place to write number of output samples
                                                );
    // decode a frame of audio sample data if possible from the passed-in data block
    //
    // return value: number of bytes we used from datablock
    // possible cases:
    //     0 bytes used, 0 samples output (need more data)
    //     N bytes used, 0 samples output (resynching the stream, keep going)
    //     N bytes used, M samples output (one frame of data)
    // note that after opening a file, you will ALWAYS get one N-bytes,0-sample
    // frame, because Vorbis always "discards" the first frame.
    //
    // Note that on resynch, stb_vorbis will rarely consume all of the buffer,
    // instead only datablock_length_in_bytes-3 or less. This is because it wants
    // to avoid missing parts of a page header if they cross a datablock boundary,
    // without writing state-machiney code to record a partial detection.
    //
    // The number of channels returned are stored in *channels (which can be
    // NULL--it is always the same as the number of channels reported by
    // get_info). *output will contain an array of float* buffers, one per
    // channel. In other words, (*output)[0][0] contains the first sample from
    // the first channel, and (*output)[1][0] contains the first sample from
    // the second channel.
    
    extern void stb_vorbis_flush_pushdata(stb_vorbis *f);
    // inform stb_vorbis that your next datablock will not be contiguous with
    // previous ones (e.g. you've seeked in the data); future attempts to decode
    // frames will cause stb_vorbis to resynchronize (as noted above), and
    // once it sees a valid Ogg page (typically 4-8KB, as large as 64KB), it
    // will begin decoding the _next_ frame.
    //
    // if you want to seek using pushdata, you need to seek in your file, then
    // call stb_vorbis_flush_pushdata(), then start calling decoding, then once
    // decoding is returning you data, call stb_vorbis_get_sample_offset, and
    // if you don't like the result, seek your file again and repeat.
#endif
    
    
    //////////   PULLING INPUT API
    
#ifndef STB_VORBIS_NO_PULLDATA_API
    // This API assumes stb_vorbis is allowed to pull data from a source--
    // either a block of memory containing the _entire_ vorbis stream, or a
    // FILE * that you or it create, or possibly some other reading mechanism
    // if you go modify the source to replace the FILE * case with some kind
    // of callback to your code. (But if you don't support seeking, you may
    // just want to go ahead and use pushdata.)
    
#if !defined(STB_VORBIS_NO_STDIO) && !defined(STB_VORBIS_NO_INTEGER_CONVERSION)
    extern int stb_vorbis_decode_filename(char *filename, int *channels, short **output);
#endif
    extern int stb_vorbis_decode_memory(unsigned char *mem, int len, int *channels, short **output);
    // decode an entire file and output the data interleaved into a malloc()ed
    // buffer stored in *output. The return value is the number of samples
    // decoded, or -1 if the file could not be opened or was not an ogg vorbis file.
    // When you're done with it, just free() the pointer returned in *output.
    
    extern stb_vorbis * stb_vorbis_open_memory(unsigned char *data, int len,
                                               int *error, stb_vorbis_alloc *alloc_buffer);
    // create an ogg vorbis decoder from an ogg vorbis stream in memory (note
    // this must be the entire stream!). on failure, returns NULL and sets *error
    
#ifndef STB_VORBIS_NO_STDIO
    extern stb_vorbis * stb_vorbis_open_filename(char *filename,
                                                 int *error, stb_vorbis_alloc *alloc_buffer);
    // create an ogg vorbis decoder from a filename via fopen(). on failure,
    // returns NULL and sets *error (possibly to VORBIS_file_open_failure).
    
    extern stb_vorbis * stb_vorbis_open_file(FILE *f, int close_handle_on_close,
                                             int *error, stb_vorbis_alloc *alloc_buffer);
    // create an ogg vorbis decoder from an open FILE *, looking for a stream at
    // the _current_ seek point (ftell). on failure, returns NULL and sets *error.
    // note that stb_vorbis must "own" this stream; if you seek it in between
    // calls to stb_vorbis, it will become confused. Morever, if you attempt to
    // perform stb_vorbis_seek_*() operations on this file, it will assume it
    // owns the _entire_ rest of the file after the start point. Use the next
    // function, stb_vorbis_open_file_section(), to limit it.
    
    extern stb_vorbis * stb_vorbis_open_file_section(FILE *f, int close_handle_on_close,
                                                     int *error, stb_vorbis_alloc *alloc_buffer, unsigned int len);
    // create an ogg vorbis decoder from an open FILE *, looking for a stream at
    // the _current_ seek point (ftell); the stream will be of length 'len' bytes.
    // on failure, returns NULL and sets *error. note that stb_vorbis must "own"
    // this stream; if you seek it in between calls to stb_vorbis, it will become
    // confused.
#endif
    
    extern int stb_vorbis_seek_frame(stb_vorbis *f, unsigned int sample_number);
    extern int stb_vorbis_seek(stb_vorbis *f, unsigned int sample_number);
    // NOT WORKING YET
    // these functions seek in the Vorbis file to (approximately) 'sample_number'.
    // after calling seek_frame(), the next call to get_frame_*() will include
    // the specified sample. after calling stb_vorbis_seek(), the next call to
    // stb_vorbis_get_samples_* will start with the specified sample. If you
    // do not need to seek to EXACTLY the target sample when using get_samples_*,
    // you can also use seek_frame().
    
    extern void stb_vorbis_seek_start(stb_vorbis *f);
    // this function is equivalent to stb_vorbis_seek(f,0), but it
    // actually works
    
    extern unsigned int stb_vorbis_stream_length_in_samples(stb_vorbis *f);
    extern float        stb_vorbis_stream_length_in_seconds(stb_vorbis *f);
    // these functions return the total length of the vorbis stream
    
    extern int stb_vorbis_get_frame_float(stb_vorbis *f, int *channels, float ***output);
    // decode the next frame and return the number of samples. the number of
    // channels returned are stored in *channels (which can be NULL--it is always
    // the same as the number of channels reported by get_info). *output will
    // contain an array of float* buffers, one per channel. These outputs will
    // be overwritten on the next call to stb_vorbis_get_frame_*.
    //
    // You generally should not intermix calls to stb_vorbis_get_frame_*()
    // and stb_vorbis_get_samples_*(), since the latter calls the former.
    
#ifndef STB_VORBIS_NO_INTEGER_CONVERSION
    extern int stb_vorbis_get_frame_short_interleaved(stb_vorbis *f, int num_c, short *buffer, int num_shorts);
    extern int stb_vorbis_get_frame_short            (stb_vorbis *f, int num_c, short **buffer, int num_samples);
#endif
    // decode the next frame and return the number of samples per channel. the
    // data is coerced to the number of channels you request according to the
    // channel coercion rules (see below). You must pass in the size of your
    // buffer(s) so that stb_vorbis will not overwrite the end of the buffer.
    // The maximum buffer size needed can be gotten from get_info(); however,
    // the Vorbis I specification implies an absolute maximum of 4096 samples
    // per channel. Note that for interleaved data, you pass in the number of
    // shorts (the size of your array), but the return value is the number of
    // samples per channel, not the total number of samples.
    
    // Channel coercion rules:
    //    Let M be the number of channels requested, and N the number of channels present,
    //    and Cn be the nth channel; let stereo L be the sum of all L and center channels,
    //    and stereo R be the sum of all R and center channels (channel assignment from the
    //    vorbis spec).
    //        M    N       output
    //        1    k      sum(Ck) for all k
    //        2    *      stereo L, stereo R
    //        k    l      k > l, the first l channels, then 0s
    //        k    l      k <= l, the first k channels
    //    Note that this is not _good_ surround etc. mixing at all! It's just so
    //    you get something useful.
    
    extern int stb_vorbis_get_samples_float_interleaved(stb_vorbis *f, int channels, float *buffer, int num_floats);
    extern int stb_vorbis_get_samples_float(stb_vorbis *f, int channels, float **buffer, int num_samples);
    // gets num_samples samples, not necessarily on a frame boundary--this requires
    // buffering so you have to supply the buffers. DOES NOT APPLY THE COERCION RULES.
    // Returns the number of samples stored per channel; it may be less than requested
    // at the end of the file. If there are no more samples in the file, returns 0.
    
#ifndef STB_VORBIS_NO_INTEGER_CONVERSION
    extern int stb_vorbis_get_samples_short_interleaved(stb_vorbis *f, int channels, short *buffer, int num_shorts);
    extern int stb_vorbis_get_samples_short(stb_vorbis *f, int channels, short **buffer, int num_samples);
#endif
    // gets num_samples samples, not necessarily on a frame boundary--this requires
    // buffering so you have to supply the buffers. Applies the coercion rules above
    // to produce 'channels' channels. Returns the number of samples stored per channel;
    // it may be less than requested at the end of the file. If there are no more
    // samples in the file, returns 0.
    
#endif
    
    ////////   ERROR CODES
    
    enum STBVorbisError
    {
        VORBIS__no_error,
        
        VORBIS_need_more_data=1,             // not a real error
        
        VORBIS_invalid_api_mixing,           // can't mix API modes
        VORBIS_outofmem,                     // not enough memory
        VORBIS_feature_not_supported,        // uses floor 0
        VORBIS_too_many_channels,            // STB_VORBIS_MAX_CHANNELS is too small
        VORBIS_file_open_failure,            // fopen() failed
        VORBIS_seek_without_length,          // can't seek in unknown-length file
        
        VORBIS_unexpected_eof=10,            // file is truncated?
        VORBIS_seek_invalid,                 // seek past EOF
        
        // decoding errors (corrupt/invalid stream) -- you probably
        // don't care about the exact details of these
        
        // vorbis errors:
        VORBIS_invalid_setup=20,
        VORBIS_invalid_stream,
        
        // ogg errors:
        VORBIS_missing_capture_pattern=30,
        VORBIS_invalid_stream_structure_version,
        VORBIS_continued_packet_flag_invalid,
        VORBIS_incorrect_stream_serial_number,
        VORBIS_invalid_first_page,
        VORBIS_bad_packet_type,
        VORBIS_cant_find_last_page,
        VORBIS_seek_failed,
    };
    
    
#ifdef __cplusplus
}
#endif

#endif // STB_VORBIS_INCLUDE_STB_VORBIS_H
//
//  HEADER ENDS HERE
//
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