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Eliminate buffers, conversions, and unused code

This commit is contained in:
krcroft 2019-11-11 13:20:11 -08:00
parent 3d8dceee57
commit 83e1979f26
No known key found for this signature in database
GPG key ID: 94D8F8D0D171A64B
4 changed files with 26 additions and 1062 deletions

View file

@ -333,8 +333,7 @@ int __Sound_strcasecmp(const char *x, const char *y)
* Allocate a Sound_Sample, and fill in most of its fields. Those that need
* to be filled in later, by a decoder, will be initialized to zero.
*/
static Sound_Sample *alloc_sample(SDL_RWops *rw, Sound_AudioInfo *desired,
Uint32 bufferSize)
static Sound_Sample *alloc_sample(SDL_RWops *rw, Sound_AudioInfo *desired)
{
/*
* !!! FIXME: We're going to need to pool samples, since the mixer
@ -356,18 +355,6 @@ static Sound_Sample *alloc_sample(SDL_RWops *rw, Sound_AudioInfo *desired,
memset(retval, '\0', sizeof (Sound_Sample));
memset(internal, '\0', sizeof (Sound_SampleInternal));
assert(bufferSize > 0);
retval->buffer = malloc(bufferSize); /* pure ugly. */
if (!retval->buffer)
{
__Sound_SetError(ERR_OUT_OF_MEMORY);
free(internal);
free(retval);
return(NULL);
} /* if */
memset(retval->buffer, '\0', bufferSize);
retval->buffer_size = bufferSize;
if (desired != NULL)
memcpy(&retval->desired, desired, sizeof (Sound_AudioInfo));
@ -426,8 +413,6 @@ static int init_sample(const Sound_DecoderFunctions *funcs,
/* success; we've got a decoder! */
/* Now we need to set up the conversion buffer... */
memcpy(&desired, (_desired != NULL) ? _desired : &sample->actual,
sizeof (Sound_AudioInfo));
@ -438,40 +423,9 @@ static int init_sample(const Sound_DecoderFunctions *funcs,
if (desired.rate == 0)
desired.rate = sample->actual.rate;
if (Sound_BuildAudioCVT(&internal->sdlcvt,
sample->actual.format,
sample->actual.channels,
sample->actual.rate,
desired.format,
desired.channels,
desired.rate,
sample->buffer_size) == -1)
{
__Sound_SetError(SDL_GetError());
funcs->close(sample);
SDL_RWseek(internal->rw, pos, SEEK_SET); /* set for next try... */
return(0);
} /* if */
if (internal->sdlcvt.len_mult > 1)
{
void *rc = realloc(sample->buffer,
sample->buffer_size * internal->sdlcvt.len_mult);
if (rc == NULL)
{
funcs->close(sample);
SDL_RWseek(internal->rw, pos, SEEK_SET); /* set for next try... */
return(0);
} /* if */
sample->buffer = rc;
} /* if */
/* these pointers are all one and the same. */
memcpy(&sample->desired, &desired, sizeof (Sound_AudioInfo));
internal->sdlcvt.buf = internal->buffer = sample->buffer;
internal->buffer_size = sample->buffer_size / internal->sdlcvt.len_mult;
internal->sdlcvt.len = internal->buffer_size;
/* Prepend our new Sound_Sample to the sample_list... */
SDL_LockMutex(samplelist_mutex);
@ -490,16 +444,12 @@ static int init_sample(const Sound_DecoderFunctions *funcs,
fmt_to_str(sample->actual.format),
sample->actual.rate,
sample->actual.channels));
SNDDBG(("On-the-fly conversion: %s.\n",
internal->sdlcvt.needed ? "ENABLED" : "DISABLED"));
return(1);
} /* init_sample */
Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext,
Sound_AudioInfo *desired, Uint32 bSize)
Sound_AudioInfo *desired)
{
Sound_Sample *retval;
decoder_element *decoder;
@ -508,7 +458,7 @@ Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext,
BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, NULL);
BAIL_IF_MACRO(rw == NULL, ERR_INVALID_ARGUMENT, NULL);
retval = alloc_sample(rw, desired, bSize);
retval = alloc_sample(rw, desired);
if (!retval)
return(NULL); /* alloc_sample() sets error message... */
@ -562,8 +512,6 @@ Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext,
/* nothing could handle the sound data... */
free(retval->opaque);
if (retval->buffer != NULL)
free(retval->buffer);
free(retval);
SDL_RWclose(rw);
__Sound_SetError(ERR_UNSUPPORTED_FORMAT);
@ -572,8 +520,7 @@ Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext,
Sound_Sample *Sound_NewSampleFromFile(const char *filename,
Sound_AudioInfo *desired,
Uint32 bufferSize)
Sound_AudioInfo *desired)
{
const char *ext;
SDL_RWops *rw;
@ -593,30 +540,9 @@ Sound_Sample *Sound_NewSampleFromFile(const char *filename,
if (ext != NULL)
ext++;
return(Sound_NewSample(rw, ext, desired, bufferSize));
return(Sound_NewSample(rw, ext, desired));
} /* Sound_NewSampleFromFile */
Sound_Sample *Sound_NewSampleFromMem(const Uint8 *data,
Uint32 size,
const char *ext,
Sound_AudioInfo *desired,
Uint32 bufferSize)
{
SDL_RWops *rw;
BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, NULL);
BAIL_IF_MACRO(data == NULL, ERR_INVALID_ARGUMENT, NULL);
BAIL_IF_MACRO(size == 0, ERR_INVALID_ARGUMENT, NULL);
rw = SDL_RWFromConstMem(data, size);
/* !!! FIXME: rw = RWops_FromMem(data, size);*/
BAIL_IF_MACRO(rw == NULL, SDL_GetError(), NULL);
return(Sound_NewSample(rw, ext, desired, bufferSize));
} /* Sound_NewSampleFromMem */
void Sound_FreeSample(Sound_Sample *sample)
{
Sound_SampleInternal *internal;
@ -665,42 +591,13 @@ void Sound_FreeSample(Sound_Sample *sample)
if (internal->rw != NULL) /* this condition is a "just in case" thing. */
SDL_RWclose(internal->rw);
if ((internal->buffer != NULL) && (internal->buffer != sample->buffer))
free(internal->buffer);
free(internal);
if (sample->buffer != NULL)
free(sample->buffer);
free(sample);
} /* Sound_FreeSample */
int Sound_SetBufferSize(Sound_Sample *sample, Uint32 newSize)
{
void *newBuf = NULL;
Sound_SampleInternal *internal = NULL;
BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, 0);
BAIL_IF_MACRO(sample == NULL, ERR_INVALID_ARGUMENT, 0);
internal = ((Sound_SampleInternal *) sample->opaque);
newBuf = realloc(sample->buffer, newSize * internal->sdlcvt.len_mult);
BAIL_IF_MACRO(newBuf == NULL, ERR_OUT_OF_MEMORY, 0);
internal->sdlcvt.buf = internal->buffer = sample->buffer = newBuf;
sample->buffer_size = newSize;
internal->buffer_size = newSize / internal->sdlcvt.len_mult;
internal->sdlcvt.len = internal->buffer_size;
return(1);
} /* Sound_SetBufferSize */
Uint32 Sound_Decode(Sound_Sample *sample)
Uint32 Sound_Decode_Direct(Sound_Sample *sample, void* buffer, Uint32 desired_frames)
{
Sound_SampleInternal *internal = NULL;
Uint32 retval = 0;
/* a boatload of sanity checks... */
BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, 0);
@ -710,73 +607,12 @@ Uint32 Sound_Decode(Sound_Sample *sample)
internal = (Sound_SampleInternal *) sample->opaque;
assert(sample->buffer != NULL);
assert(sample->buffer_size > 0);
assert(internal->buffer != NULL);
assert(internal->buffer_size > 0);
/* reset EAGAIN. Decoder can flip it back on if it needs to. */
sample->flags &= ~SOUND_SAMPLEFLAG_EAGAIN;
retval = internal->funcs->read(sample);
if (retval > 0 && internal->sdlcvt.needed)
{
internal->sdlcvt.len = retval;
Sound_ConvertAudio(&internal->sdlcvt);
retval = internal->sdlcvt.len_cvt;
} /* if */
return(retval);
return internal->funcs->read(sample, buffer, desired_frames);
} /* Sound_Decode */
Uint32 Sound_DecodeAll(Sound_Sample *sample)
{
Sound_SampleInternal *internal = NULL;
void *buf = NULL;
Uint32 newBufSize = 0;
BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, 0);
BAIL_IF_MACRO(sample->flags & SOUND_SAMPLEFLAG_EOF, ERR_PREV_EOF, 0);
BAIL_IF_MACRO(sample->flags & SOUND_SAMPLEFLAG_ERROR, ERR_PREV_ERROR, 0);
internal = (Sound_SampleInternal *) sample->opaque;
while ( ((sample->flags & SOUND_SAMPLEFLAG_EOF) == 0) &&
((sample->flags & SOUND_SAMPLEFLAG_ERROR) == 0) )
{
Uint32 br = Sound_Decode(sample);
void *ptr = realloc(buf, newBufSize + br);
if (ptr == NULL)
{
sample->flags |= SOUND_SAMPLEFLAG_ERROR;
__Sound_SetError(ERR_OUT_OF_MEMORY);
} /* if */
else
{
buf = ptr;
memcpy( ((char *) buf) + newBufSize, sample->buffer, br );
newBufSize += br;
} /* else */
} /* while */
if (buf == NULL) /* ...in case first call to realloc() fails... */
return(sample->buffer_size);
if (internal->buffer != sample->buffer)
free(internal->buffer);
free(sample->buffer);
internal->sdlcvt.buf = internal->buffer = sample->buffer = buf;
sample->buffer_size = newBufSize;
internal->buffer_size = newBufSize / internal->sdlcvt.len_mult;
internal->sdlcvt.len = internal->buffer_size;
return(newBufSize);
} /* Sound_DecodeAll */
int Sound_Rewind(Sound_Sample *sample)
{
Sound_SampleInternal *internal;
@ -825,4 +661,3 @@ Sint32 Sound_GetDuration(Sound_Sample *sample)
} /* Sound_GetDuration */
/* end of SDL_sound.c ... */

View file

@ -94,7 +94,6 @@ extern "C" {
* \sa Sound_SampleNew
* \sa Sound_SampleNewFromFile
* \sa Sound_SampleDecode
* \sa Sound_SampleDecodeAll
* \sa Sound_SampleSeek
*/
typedef enum
@ -174,8 +173,6 @@ typedef struct
const Sound_DecoderInfo *decoder; /**< Decoder used for this sample. */
Sound_AudioInfo desired; /**< Desired audio format for conversion. */
Sound_AudioInfo actual; /**< Actual audio format of sample. */
void *buffer; /**< Decoded sound data lands in here. */
Uint32 buffer_size; /**< Current size of (buffer), in bytes (Uint8). */
Uint32 flags; /**< Flags relating to this sample. */
} Sound_Sample;
@ -440,41 +437,7 @@ SNDDECLSPEC void SDLCALL Sound_ClearError(void);
*/
SNDDECLSPEC Sound_Sample * SDLCALL Sound_NewSample(SDL_RWops *rw,
const char *ext,
Sound_AudioInfo *desired,
Uint32 bufferSize);
/**
* \fn Sound_Sample *Sound_NewSampleFromMem(const Uint8 *data, Sound_AudioInfo *desired, Uint32 bufferSize)
* \brief Start decoding a new sound sample from a file on disk.
*
* This is identical to Sound_NewSample(), but it creates an SDL_RWops for you
* from the (size) bytes of memory referenced by (data).
*
* This can pool RWops structures, so it may fragment the heap less over time
* than using SDL_RWFromMem().
*
* \param filename file containing sound data.
* \param desired Format to convert sound data into. Can usually be NULL,
* if you don't need conversion.
* \param bufferSize size, in bytes, of initial read buffer.
* \return Sound_Sample pointer, which is used as a handle to several other
* SDL_sound APIs. NULL on error. If error, use
* Sound_GetError() to see what went wrong.
*
* \sa Sound_NewSample
* \sa Sound_SetBufferSize
* \sa Sound_Decode
* \sa Sound_DecodeAll
* \sa Sound_Seek
* \sa Sound_Rewind
* \sa Sound_FreeSample
*/
SNDDECLSPEC Sound_Sample * SDLCALL Sound_NewSampleFromMem(const Uint8 *data,
Uint32 size,
const char *ext,
Sound_AudioInfo *desired,
Uint32 bufferSize);
Sound_AudioInfo *desired);
/**
* \fn Sound_Sample *Sound_NewSampleFromFile(const char *filename, Sound_AudioInfo *desired, Uint32 bufferSize)
@ -507,8 +470,7 @@ SNDDECLSPEC Sound_Sample * SDLCALL Sound_NewSampleFromMem(const Uint8 *data,
* \sa Sound_FreeSample
*/
SNDDECLSPEC Sound_Sample * SDLCALL Sound_NewSampleFromFile(const char *fname,
Sound_AudioInfo *desired,
Uint32 bufferSize);
Sound_AudioInfo *desired);
/**
* \fn void Sound_FreeSample(Sound_Sample *sample)
@ -551,93 +513,27 @@ SNDDECLSPEC void SDLCALL Sound_FreeSample(Sound_Sample *sample);
*/
SNDDECLSPEC Sint32 SDLCALL Sound_GetDuration(Sound_Sample *sample);
/**
* \fn int Sound_SetBufferSize(Sound_Sample *sample, Uint32 new_size)
* \brief Change the current buffer size for a sample.
* \fn Uint32 Sound_Decode_Direct(Sound_Sample *sample)
* \brief Decode more of the sound data in a Sound_Sample directly into
* the supplied buffer.
*
* If the buffer size could be changed, then the sample->buffer and
* sample->buffer_size fields will reflect that. If they could not be
* changed, then your original sample state is preserved. If the buffer is
* shrinking, the data at the end of buffer is truncated. If the buffer is
* growing, the contents of the new space at the end is undefined until you
* decode more into it or initialize it yourself.
*
* The buffer size specified must be a multiple of the size of a single
* sample point. So, if you want 16-bit, stereo samples, then your sample
* point size is (2 channels * 16 bits), or 32 bits per sample, which is four
* bytes. In such a case, you could specify 128 or 132 bytes for a buffer,
* but not 129, 130, or 131 (although in reality, you'll want to specify a
* MUCH larger buffer).
*
* \param sample The Sound_Sample whose buffer to modify.
* \param new_size The desired size, in bytes, of the new buffer.
* \return non-zero if buffer size changed, zero on failure.
*
* \sa Sound_Decode
* \sa Sound_DecodeAll
*/
SNDDECLSPEC int SDLCALL Sound_SetBufferSize(Sound_Sample *sample,
Uint32 new_size);
/**
* \fn Uint32 Sound_Decode(Sound_Sample *sample)
* \brief Decode more of the sound data in a Sound_Sample.
*
* It will decode at most sample->buffer_size bytes into sample->buffer in the
* desired format, and return the number of decoded bytes.
* If sample->buffer_size bytes could not be decoded, then please refer to
* It will decode at most desired_frames into buffer, and return the number
* frames decoded.
* If the number of desired_frames could not be decoded, then please refer to
* sample->flags to determine if this was an end-of-stream or error condition.
*
* \param sample Do more decoding to this Sound_Sample.
* \return number of bytes decoded into sample->buffer. If it is less than
* sample->buffer_size, then you should check sample->flags to see
* \param buffer PCM frames into this buffer.
* \param desired_frames indicates how many PCM should be decoded.
* \return number of frames decoded into buffer. If it is less than
* desired_frames, then you should check sample->flags to see
* what the current state of the sample is (EOF, error, read again).
*
* \sa Sound_DecodeAll
* \sa Sound_SetBufferSize
* \sa Sound_Seek
* \sa Sound_Rewind
*/
SNDDECLSPEC Uint32 SDLCALL Sound_Decode(Sound_Sample *sample);
/**
* \fn Uint32 Sound_DecodeAll(Sound_Sample *sample)
* \brief Decode the remainder of the sound data in a Sound_Sample.
*
* This will dynamically allocate memory for the ENTIRE remaining sample.
* sample->buffer_size and sample->buffer will be updated to reflect the
* new buffer. Please refer to sample->flags to determine if the decoding
* finished due to an End-of-stream or error condition.
*
* Be aware that sound data can take a large amount of memory, and that
* this function may block for quite awhile while processing. Also note
* that a streaming source (for example, from a SDL_RWops that is getting
* fed from an Internet radio feed that doesn't end) may fill all available
* memory before giving up...be sure to use this on finite sound sources
* only!
*
* When decoding the sample in its entirety, the work is done one buffer at a
* time. That is, sound is decoded in sample->buffer_size blocks, and
* appended to a continually-growing buffer until the decoding completes.
* That means that this function will need enough RAM to hold approximately
* sample->buffer_size bytes plus the complete decoded sample at most. The
* larger your buffer size, the less overhead this function needs, but beware
* the possibility of paging to disk. Best to make this user-configurable if
* the sample isn't specific and small.
*
* \param sample Do all decoding for this Sound_Sample.
* \return number of bytes decoded into sample->buffer. You should check
* sample->flags to see what the current state of the sample is
* (EOF, error, read again).
*
* \sa Sound_Decode
* \sa Sound_SetBufferSize
*/
SNDDECLSPEC Uint32 SDLCALL Sound_DecodeAll(Sound_Sample *sample);
SNDDECLSPEC Uint32 SDLCALL Sound_Decode_Direct(Sound_Sample *sample, void* buffer, Uint32 desired_frames);
/**
* \fn int Sound_Rewind(Sound_Sample *sample)

View file

@ -126,9 +126,6 @@ typedef struct __SOUND_DECODERFUNCTIONS__
* Sound_Sample *prev; (offlimits)
* SDL_RWops *rw; (can use, but do NOT close it)
* const Sound_DecoderFunctions *funcs; (that's this structure)
* Sound_AudioCVT sdlcvt; (offlimits)
* void *buffer; (offlimits until read() method)
* Uint32 buffer_size; (offlimits until read() method)
* void *decoder_private; (read and write access)
*
* in rest of Sound_Sample:
@ -136,8 +133,6 @@ typedef struct __SOUND_DECODERFUNCTIONS__
* const Sound_DecoderInfo *decoder; (read only)
* Sound_AudioInfo desired; (read only, usually not needed here)
* Sound_AudioInfo actual; (please fill this in)
* void *buffer; (offlimits)
* Uint32 buffer_size; (offlimits)
* Sound_SampleFlags flags; (set appropriately)
*/
int (*open)(Sound_Sample *sample, const char *ext);
@ -157,15 +152,12 @@ typedef struct __SOUND_DECODERFUNCTIONS__
* Sound_SampleInternal *internal;
* internal = (Sound_SampleInternal *) sample->opaque;
*
* ...and then start decoding. Fill in up to internal->buffer_size
* bytes of decoded sound in the space pointed to by
* internal->buffer. The encoded data is read in from internal->rw.
* Data should be decoded in the format specified during the
* decoder's open() method in the sample->actual field. The
* conversion to the desired format is done at a higher level.
* ...and then start decoding. Fill in up to desired_frames
* PCM frames of decoded sound into the space pointed to by
* buffer. The encoded data is read in from internal->rw.
*
* The return value is the number of bytes decoded into
* internal->buffer, which can be no more than internal->buffer_size,
* The return value is the number of frames decoded into
* buffer, which can be no more than desired_frames,
* but can be less. If it is less, you should set a state flag:
*
* If there's just no more data (end of file, etc), then do:
@ -186,7 +178,7 @@ typedef struct __SOUND_DECODERFUNCTIONS__
* SOUND_SAMPLEFLAG_EAGAIN flag is reset before each call to this
* method.
*/
Uint32 (*read)(Sound_Sample *sample);
Uint32 (*read)(Sound_Sample *sample, void* buffer, Uint32 desired_frames);
/*
* Reset the decoding to the beginning of the stream. Nonzero on
@ -223,31 +215,6 @@ typedef struct __SOUND_DECODERFUNCTIONS__
int (*seek)(Sound_Sample *sample, Uint32 ms);
} Sound_DecoderFunctions;
/* A structure to hold a set of audio conversion filters and buffers */
typedef struct Sound_AudioCVT
{
int needed; /* Set to 1 if conversion possible */
Uint16 src_format; /* Source audio format */
Uint16 dst_format; /* Target audio format */
double rate_incr; /* Rate conversion increment */
Uint8 *buf; /* Buffer to hold entire audio data */
int len; /* Length of original audio buffer */
int len_cvt; /* Length of converted audio buffer */
int len_mult; /* buffer must be len*len_mult big */
double len_ratio; /* Given len, final size is len*len_ratio */
void (*filters[20])(struct Sound_AudioCVT *cvt, Uint16 *format);
int filter_index; /* Current audio conversion function */
} Sound_AudioCVT;
extern SNDDECLSPEC int Sound_BuildAudioCVT(Sound_AudioCVT *cvt,
Uint16 src_format, Uint8 src_channels, Uint32 src_rate,
Uint16 dst_format, Uint8 dst_channels, Uint32 dst_rate,
Uint32 dst_size);
extern SNDDECLSPEC int Sound_ConvertAudio(Sound_AudioCVT *cvt);
typedef void (*MixFunc)(float *dst, void *src, Uint32 frames, float *gains);
typedef struct __SOUND_SAMPLEINTERNAL__
@ -256,7 +223,6 @@ typedef struct __SOUND_SAMPLEINTERNAL__
Sound_Sample *prev;
SDL_RWops *rw;
const Sound_DecoderFunctions *funcs;
Sound_AudioCVT sdlcvt;
void *buffer;
Uint32 buffer_size;
void *decoder_private;

View file

@ -1,733 +0,0 @@
/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Sam Lantinga
slouken@devolution.com
*/
/*
* This file was derived from SDL's SDL_audiocvt.c and is an attempt to
* address the shortcomings of it.
*
* Perhaps we can adapt some good filters from SoX?
*/
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include "SDL_sound.h"
#define __SDL_SOUND_INTERNAL__
#include "SDL_sound_internal.h"
/* Functions for audio drivers to perform runtime conversion of audio format */
/*
* Toggle endianness. This filter is, of course, only applied to 16-bit
* audio data.
*/
static void Sound_ConvertEndian(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
Uint8 *data, tmp;
/* SNDDBG(("Converting audio endianness\n")); */
data = cvt->buf;
for (i = cvt->len_cvt / 2; i; --i)
{
tmp = data[0];
data[0] = data[1];
data[1] = tmp;
data += 2;
} /* for */
*format = (*format ^ 0x1000);
} /* Sound_ConvertEndian */
/*
* Toggle signed/unsigned. Apparently this is done by toggling the most
* significant bit of each sample.
*/
static void Sound_ConvertSign(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
Uint8 *data;
/* SNDDBG(("Converting audio signedness\n")); */
data = cvt->buf;
/* 16-bit sound? */
if ((*format & 0xFF) == 16)
{
/* Little-endian? */
if ((*format & 0x1000) != 0x1000)
++data;
for (i = cvt->len_cvt / 2; i; --i)
{
*data ^= 0x80;
data += 2;
} /* for */
} /* if */
else
{
for (i = cvt->len_cvt; i; --i)
*data++ ^= 0x80;
} /* else */
*format = (*format ^ 0x8000);
} /* Sound_ConvertSign */
/*
* Convert 16-bit to 8-bit. This is done by taking the most significant byte
* of each 16-bit sample.
*/
static void Sound_Convert8(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
Uint8 *src, *dst;
/* SNDDBG(("Converting to 8-bit\n")); */
src = cvt->buf;
dst = cvt->buf;
/* Little-endian? */
if ((*format & 0x1000) != 0x1000)
++src;
for (i = cvt->len_cvt / 2; i; --i)
{
*dst = *src;
src += 2;
dst += 1;
} /* for */
*format = ((*format & ~0x9010) | AUDIO_U8);
cvt->len_cvt /= 2;
} /* Sound_Convert8 */
/* Convert 8-bit to 16-bit - LSB */
static void Sound_Convert16LSB(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
Uint8 *src, *dst;
/* SNDDBG(("Converting to 16-bit LSB\n")); */
src = cvt->buf + cvt->len_cvt;
dst = cvt->buf + cvt->len_cvt * 2;
for (i = cvt->len_cvt; i; --i)
{
src -= 1;
dst -= 2;
dst[1] = *src;
dst[0] = 0;
} /* for */
*format = ((*format & ~0x0008) | AUDIO_U16LSB);
cvt->len_cvt *= 2;
} /* Sound_Convert16LSB */
/* Convert 8-bit to 16-bit - MSB */
static void Sound_Convert16MSB(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
Uint8 *src, *dst;
/* SNDDBG(("Converting to 16-bit MSB\n")); */
src = cvt->buf + cvt->len_cvt;
dst = cvt->buf + cvt->len_cvt * 2;
for (i = cvt->len_cvt; i; --i)
{
src -= 1;
dst -= 2;
dst[0] = *src;
dst[1] = 0;
} /* for */
*format = ((*format & ~0x0008) | AUDIO_U16MSB);
cvt->len_cvt *= 2;
} /* Sound_Convert16MSB */
/* Duplicate a mono channel to both stereo channels */
static void Sound_ConvertStereo(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
/* SNDDBG(("Converting to stereo\n")); */
/* 16-bit sound? */
if ((*format & 0xFF) == 16)
{
Uint16 *src, *dst;
src = (Uint16 *) (cvt->buf + cvt->len_cvt);
dst = (Uint16 *) (cvt->buf + cvt->len_cvt * 2);
for (i = cvt->len_cvt/2; i; --i)
{
dst -= 2;
src -= 1;
dst[0] = src[0];
dst[1] = src[0];
} /* for */
} /* if */
else
{
Uint8 *src, *dst;
src = cvt->buf + cvt->len_cvt;
dst = cvt->buf + cvt->len_cvt * 2;
for (i = cvt->len_cvt; i; --i)
{
dst -= 2;
src -= 1;
dst[0] = src[0];
dst[1] = src[0];
} /* for */
} /* else */
cvt->len_cvt *= 2;
} /* Sound_ConvertStereo */
/* Effectively mix right and left channels into a single channel */
static void Sound_ConvertMono(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
Sint32 sample;
Uint8 *u_src, *u_dst;
Sint8 *s_src, *s_dst;
/* SNDDBG(("Converting to mono\n")); */
switch (*format)
{
case AUDIO_U8:
u_src = cvt->buf;
u_dst = cvt->buf;
for (i = cvt->len_cvt / 2; i; --i)
{
sample = u_src[0] + u_src[1];
*u_dst = (sample > 255) ? 255 : sample;
u_src += 2;
u_dst += 1;
} /* for */
break;
case AUDIO_S8:
s_src = (Sint8 *) cvt->buf;
s_dst = (Sint8 *) cvt->buf;
for (i = cvt->len_cvt / 2; i; --i)
{
sample = s_src[0] + s_src[1];
if (sample > 127)
*s_dst = 127;
else if (sample < -128)
*s_dst = -128;
else
*s_dst = sample;
s_src += 2;
s_dst += 1;
} /* for */
break;
case AUDIO_U16MSB:
u_src = cvt->buf;
u_dst = cvt->buf;
for (i = cvt->len_cvt / 4; i; --i)
{
sample = (Uint16) ((u_src[0] << 8) | u_src[1])
+ (Uint16) ((u_src[2] << 8) | u_src[3]);
if (sample > 65535)
{
u_dst[0] = 0xFF;
u_dst[1] = 0xFF;
} /* if */
else
{
u_dst[1] = (sample & 0xFF);
sample >>= 8;
u_dst[0] = (sample & 0xFF);
} /* else */
u_src += 4;
u_dst += 2;
} /* for */
break;
case AUDIO_U16LSB:
u_src = cvt->buf;
u_dst = cvt->buf;
for (i = cvt->len_cvt / 4; i; --i)
{
sample = (Uint16) ((u_src[1] << 8) | u_src[0])
+ (Uint16) ((u_src[3] << 8) | u_src[2]);
if (sample > 65535)
{
u_dst[0] = 0xFF;
u_dst[1] = 0xFF;
} /* if */
else
{
u_dst[0] = (sample & 0xFF);
sample >>= 8;
u_dst[1] = (sample & 0xFF);
} /* else */
u_src += 4;
u_dst += 2;
} /* for */
break;
case AUDIO_S16MSB:
u_src = cvt->buf;
u_dst = cvt->buf;
for (i = cvt->len_cvt / 4; i; --i)
{
sample = (Sint16) ((u_src[0] << 8) | u_src[1])
+ (Sint16) ((u_src[2] << 8) | u_src[3]);
if (sample > 32767)
{
u_dst[0] = 0x7F;
u_dst[1] = 0xFF;
} /* if */
else if (sample < -32768)
{
u_dst[0] = 0x80;
u_dst[1] = 0x00;
} /* else if */
else
{
u_dst[1] = (sample & 0xFF);
sample >>= 8;
u_dst[0] = (sample & 0xFF);
} /* else */
u_src += 4;
u_dst += 2;
} /* for */
break;
case AUDIO_S16LSB:
u_src = cvt->buf;
u_dst = cvt->buf;
for (i = cvt->len_cvt / 4; i; --i)
{
sample = (Sint16) ((u_src[1] << 8) | u_src[0])
+ (Sint16) ((u_src[3] << 8) | u_src[2]);
if (sample > 32767)
{
u_dst[1] = 0x7F;
u_dst[0] = 0xFF;
} /* if */
else if (sample < -32768)
{
u_dst[1] = 0x80;
u_dst[0] = 0x00;
} /* else if */
else
{
u_dst[0] = (sample & 0xFF);
sample >>= 8;
u_dst[1] = (sample & 0xFF);
} /* else */
u_src += 4;
u_dst += 2;
} /* for */
break;
} /* switch */
cvt->len_cvt /= 2;
} /* Sound_ConvertMono */
/* Convert rate up by multiple of 2 */
static void Sound_RateMUL2(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
Uint8 *src, *dst;
/* SNDDBG(("Converting audio rate * 2\n")); */
src = cvt->buf + cvt->len_cvt;
dst = cvt->buf + cvt->len_cvt*2;
/* 8- or 16-bit sound? */
switch (*format & 0xFF)
{
case 8:
for (i = cvt->len_cvt; i; --i)
{
src -= 1;
dst -= 2;
dst[0] = src[0];
dst[1] = src[0];
} /* for */
break;
case 16:
for (i = cvt->len_cvt / 2; i; --i)
{
src -= 2;
dst -= 4;
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[0];
dst[3] = src[1];
} /* for */
break;
} /* switch */
cvt->len_cvt *= 2;
} /* Sound_RateMUL2 */
/* Convert rate down by multiple of 2 */
static void Sound_RateDIV2(Sound_AudioCVT *cvt, Uint16 *format)
{
int i;
Uint8 *src, *dst;
/* SNDDBG(("Converting audio rate / 2\n")); */
src = cvt->buf;
dst = cvt->buf;
/* 8- or 16-bit sound? */
switch (*format & 0xFF)
{
case 8:
for (i = cvt->len_cvt / 2; i; --i)
{
dst[0] = src[0];
src += 2;
dst += 1;
} /* for */
break;
case 16:
for (i = cvt->len_cvt / 4; i; --i)
{
dst[0] = src[0];
dst[1] = src[1];
src += 4;
dst += 2;
}
break;
} /* switch */
cvt->len_cvt /= 2;
} /* Sound_RateDIV2 */
/* Very slow rate conversion routine */
static void Sound_RateSLOW(Sound_AudioCVT *cvt, Uint16 *format)
{
double ipos;
int i, clen;
Uint8 *output8;
Uint16 *output16;
/* SNDDBG(("Converting audio rate * %4.4f\n", 1.0/cvt->rate_incr)); */
clen = (int) ((double) cvt->len_cvt / cvt->rate_incr);
if (cvt->rate_incr > 1.0)
{
/* 8- or 16-bit sound? */
switch (*format & 0xFF)
{
case 8:
output8 = cvt->buf;
ipos = 0.0;
for (i = clen; i; --i)
{
*output8 = cvt->buf[(int) ipos];
ipos += cvt->rate_incr;
output8 += 1;
} /* for */
break;
case 16:
output16 = (Uint16 *) cvt->buf;
clen &= ~1;
ipos = 0.0;
for (i = clen / 2; i; --i)
{
*output16 = ((Uint16 *) cvt->buf)[(int) ipos];
ipos += cvt->rate_incr;
output16 += 1;
} /* for */
break;
} /* switch */
} /* if */
else
{
/* 8- or 16-bit sound */
switch (*format & 0xFF)
{
case 8:
output8 = cvt->buf + clen;
ipos = (double) cvt->len_cvt;
for (i = clen; i; --i)
{
ipos -= cvt->rate_incr;
output8 -= 1;
*output8 = cvt->buf[(int) ipos];
} /* for */
break;
case 16:
clen &= ~1;
output16 = (Uint16 *) (cvt->buf + clen);
ipos = (double) cvt->len_cvt / 2;
for (i = clen / 2; i; --i)
{
ipos -= cvt->rate_incr;
output16 -= 1;
*output16 = ((Uint16 *) cvt->buf)[(int) ipos];
} /* for */
break;
} /* switch */
} /* else */
cvt->len_cvt = clen;
} /* Sound_RateSLOW */
int Sound_ConvertAudio(Sound_AudioCVT *cvt)
{
Uint16 format;
/* Make sure there's data to convert */
if (cvt->buf == NULL)
{
__Sound_SetError("No buffer allocated for conversion");
return(-1);
} /* if */
/* Return okay if no conversion is necessary */
cvt->len_cvt = cvt->len;
if (cvt->filters[0] == NULL)
return(0);
/* Set up the conversion and go! */
format = cvt->src_format;
for (cvt->filter_index = 0; cvt->filters[cvt->filter_index];
cvt->filter_index++)
{
cvt->filters[cvt->filter_index](cvt, &format);
}
return(0);
} /* Sound_ConvertAudio */
/*
* Creates a set of audio filters to convert from one format to another.
* Returns -1 if the format conversion is not supported, or 1 if the
* audio filter is set up.
*/
int Sound_BuildAudioCVT(Sound_AudioCVT *cvt,
Uint16 src_format, Uint8 src_channels, Uint32 src_rate,
Uint16 dst_format, Uint8 dst_channels, Uint32 dst_rate,
Uint32 dst_size)
{
/* Start off with no conversion necessary */
cvt->needed = 0;
cvt->filter_index = 0;
cvt->filters[0] = NULL;
cvt->len_mult = 1;
cvt->len_ratio = 1.0;
/* First filter: Endian conversion from src to dst */
if ((src_format & 0x1000) != (dst_format & 0x1000) &&
((src_format & 0xff) != 8))
{
SNDDBG(("Adding filter: Sound_ConvertEndian\n"));
cvt->filters[cvt->filter_index++] = Sound_ConvertEndian;
} /* if */
/* Second filter: Sign conversion -- signed/unsigned */
if ((src_format & 0x8000) != (dst_format & 0x8000))
{
SNDDBG(("Adding filter: Sound_ConvertSign\n"));
cvt->filters[cvt->filter_index++] = Sound_ConvertSign;
} /* if */
/* Next filter: Convert 16 bit <--> 8 bit PCM. */
if ((src_format & 0xFF) != (dst_format & 0xFF))
{
switch (dst_format & 0x10FF)
{
case AUDIO_U8:
SNDDBG(("Adding filter: Sound_Convert8\n"));
cvt->filters[cvt->filter_index++] = Sound_Convert8;
cvt->len_ratio /= 2;
break;
case AUDIO_U16LSB:
SNDDBG(("Adding filter: Sound_Convert16LSB\n"));
cvt->filters[cvt->filter_index++] = Sound_Convert16LSB;
cvt->len_mult *= 2;
cvt->len_ratio *= 2;
break;
case AUDIO_U16MSB:
SNDDBG(("Adding filter: Sound_Convert16MSB\n"));
cvt->filters[cvt->filter_index++] = Sound_Convert16MSB;
cvt->len_mult *= 2;
cvt->len_ratio *= 2;
break;
} /* switch */
} /* if */
/* Next filter: Mono/Stereo conversion */
if (src_channels != dst_channels)
{
while ((src_channels * 2) <= dst_channels)
{
SNDDBG(("Adding filter: Sound_ConvertStereo\n"));
cvt->filters[cvt->filter_index++] = Sound_ConvertStereo;
cvt->len_mult *= 2;
src_channels *= 2;
cvt->len_ratio *= 2;
} /* while */
/* This assumes that 4 channel audio is in the format:
* Left {front/back} + Right {front/back}
* so converting to L/R stereo works properly.
*/
while (((src_channels % 2) == 0) &&
((src_channels / 2) >= dst_channels))
{
SNDDBG(("Adding filter: Sound_ConvertMono\n"));
cvt->filters[cvt->filter_index++] = Sound_ConvertMono;
src_channels /= 2;
cvt->len_ratio /= 2;
} /* while */
if ( src_channels != dst_channels ) {
/* Uh oh.. */;
} /* if */
} /* if */
/* Do rate conversion */
cvt->rate_incr = 0.0;
if ((src_rate / 100) != (dst_rate / 100))
{
Uint32 hi_rate, lo_rate;
int len_mult;
double len_ratio;
void (*rate_cvt)(Sound_AudioCVT *cvt, Uint16 *format);
if (src_rate > dst_rate)
{
hi_rate = src_rate;
lo_rate = dst_rate;
SNDDBG(("Adding filter: Sound_RateDIV2\n"));
rate_cvt = Sound_RateDIV2;
len_mult = 1;
len_ratio = 0.5;
} /* if */
else
{
hi_rate = dst_rate;
lo_rate = src_rate;
SNDDBG(("Adding filter: Sound_RateMUL2\n"));
rate_cvt = Sound_RateMUL2;
len_mult = 2;
len_ratio = 2.0;
} /* else */
/* If hi_rate = lo_rate*2^x then conversion is easy */
while (((lo_rate * 2) / 100) <= (hi_rate / 100))
{
cvt->filters[cvt->filter_index++] = rate_cvt;
cvt->len_mult *= len_mult;
lo_rate *= 2;
cvt->len_ratio *= len_ratio;
} /* while */
/* We may need a slow conversion here to finish up */
if ((lo_rate / 100) != (hi_rate / 100))
{
if (src_rate < dst_rate)
{
cvt->rate_incr = (double) lo_rate / hi_rate;
cvt->len_mult *= 2;
cvt->len_ratio /= cvt->rate_incr;
} /* if */
else
{
cvt->rate_incr = (double) hi_rate / lo_rate;
cvt->len_ratio *= cvt->rate_incr;
} /* else */
SNDDBG(("Adding filter: Sound_RateSLOW\n"));
cvt->filters[cvt->filter_index++] = Sound_RateSLOW;
} /* if */
} /* if */
/* Set up the filter information */
if (cvt->filter_index != 0)
{
cvt->needed = 1;
cvt->src_format = src_format;
cvt->dst_format = dst_format;
cvt->len = 0;
cvt->buf = NULL;
cvt->filters[cvt->filter_index] = NULL;
} /* if */
return(cvt->needed);
} /* Sound_BuildAudioCVT */
/* end of audio_convert.c ... */