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Check mixer parameters just once when a stream is created.
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@stump
stump committed Dec 26, 2012
1 parent 058c0cb commit 9fc5a40
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Showing 2 changed files with 44 additions and 34 deletions.
4 changes: 4 additions & 0 deletions src/MixStream.h
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Expand Up @@ -40,4 +40,8 @@ GQuark mix_stream_error_quark(void);
GQuark mix_stream_ov_error_quark(void);
#define MIX_STREAM_OV_ERROR mix_stream_ov_error_quark()

typedef enum {
MIX_STREAM_MIXER_UNINIT
} MixStreamError;

#endif
74 changes: 40 additions & 34 deletions src/MixStreamCore.c
View file
Expand Up @@ -36,6 +36,12 @@ struct _MixStream {
Mix_Chunk chunk;
gboolean input_eof;
gboolean eof;
int out_freq;
Uint16 out_format;
int out_channels;
int out_sample_size;
gboolean out_samples_signed;
gboolean byteswap_needed;
};

static GHashTable* chan_table = NULL;
Expand All @@ -62,6 +68,31 @@ MixStream* mix_stream_new(int samprate, int channels, mix_stream_read_cb read_cb
stream->cb_data = data;
stream->channel = -1;
stream->chunk.volume = MIX_MAX_VOLUME;

if (!Mix_QuerySpec(&stream->out_freq, &stream->out_format, &stream->out_channels)) {
g_set_error(err, MIX_STREAM_ERROR, MIX_STREAM_MIXER_UNINIT,
"SDL_mixer is not initialized");
g_free(stream);
return NULL;
}

switch (stream->out_format) {
case AUDIO_S8: stream->out_sample_size = 1; stream->out_samples_signed = TRUE ; stream->byteswap_needed = FALSE; break;
case AUDIO_U8: stream->out_sample_size = 1; stream->out_samples_signed = FALSE; stream->byteswap_needed = FALSE; break;
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
case AUDIO_S16LSB: stream->out_sample_size = 2; stream->out_samples_signed = TRUE ; stream->byteswap_needed = FALSE; break;
case AUDIO_U16LSB: stream->out_sample_size = 2; stream->out_samples_signed = FALSE; stream->byteswap_needed = FALSE; break;
case AUDIO_S16MSB: stream->out_sample_size = 2; stream->out_samples_signed = TRUE ; stream->byteswap_needed = TRUE ; break;
case AUDIO_U16MSB: stream->out_sample_size = 2; stream->out_samples_signed = FALSE; stream->byteswap_needed = TRUE ; break;
#else
case AUDIO_S16LSB: stream->out_sample_size = 2; stream->out_samples_signed = TRUE ; stream->byteswap_needed = TRUE ; break;
case AUDIO_U16LSB: stream->out_sample_size = 2; stream->out_samples_signed = FALSE; stream->byteswap_needed = TRUE ; break;
case AUDIO_S16MSB: stream->out_sample_size = 2; stream->out_samples_signed = TRUE ; stream->byteswap_needed = FALSE; break;
case AUDIO_U16MSB: stream->out_sample_size = 2; stream->out_samples_signed = FALSE; stream->byteswap_needed = FALSE; break;
#endif
default: g_assert_not_reached(); break;
}

return stream;
}

Expand Down Expand Up @@ -132,13 +163,7 @@ static gboolean _mix_stream_nextchunk(MixStream* stream, gsize size)
// perform any necessary conversions
int needed_frames;
int obtained_frames;
int sample_size;
gboolean samples_signed;
gboolean byteswap_needed;
float* floatbuf;
int out_freq;
Uint16 out_format;
int out_channels;
guint8* out_buf;

if (stream->eof)
Expand All @@ -150,26 +175,7 @@ static gboolean _mix_stream_nextchunk(MixStream* stream, gsize size)
}
out_buf = stream->chunk.abuf;

Mix_QuerySpec(&out_freq, &out_format, &out_channels);

switch (out_format) {
case AUDIO_S8: sample_size = 1; samples_signed = TRUE ; byteswap_needed = FALSE; break;
case AUDIO_U8: sample_size = 1; samples_signed = FALSE; byteswap_needed = FALSE; break;
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
case AUDIO_S16LSB: sample_size = 2; samples_signed = TRUE ; byteswap_needed = FALSE; break;
case AUDIO_U16LSB: sample_size = 2; samples_signed = FALSE; byteswap_needed = FALSE; break;
case AUDIO_S16MSB: sample_size = 2; samples_signed = TRUE ; byteswap_needed = TRUE ; break;
case AUDIO_U16MSB: sample_size = 2; samples_signed = FALSE; byteswap_needed = TRUE ; break;
#else
case AUDIO_S16LSB: sample_size = 2; samples_signed = TRUE ; byteswap_needed = TRUE ; break;
case AUDIO_U16LSB: sample_size = 2; samples_signed = FALSE; byteswap_needed = TRUE ; break;
case AUDIO_S16MSB: sample_size = 2; samples_signed = TRUE ; byteswap_needed = FALSE; break;
case AUDIO_U16MSB: sample_size = 2; samples_signed = FALSE; byteswap_needed = FALSE; break;
#endif
default: g_assert_not_reached(); break;
}

needed_frames = size / (out_channels * sample_size);
needed_frames = size / (stream->out_channels * stream->out_sample_size);

floatbuf = g_newa(float, needed_frames * stream->channels);
obtained_frames = _mix_stream_fill_floatbuf(stream, floatbuf, needed_frames, stream->channels);
Expand All @@ -179,34 +185,34 @@ static gboolean _mix_stream_nextchunk(MixStream* stream, gsize size)
while (size > 0) {
float current_sample = *(floatbuf++);
/* If we're converting stereo to mono, average this sample with the other channel's. */
if (stream->channels == 2 && out_channels == 1)
if (stream->channels == 2 && stream->out_channels == 1)
current_sample = (float)(0.5 * (current_sample + *(floatbuf++)));

#define OUTPUT_SAMPLE(type, value) { *(type*)out_buf = (type)(value); out_buf += sizeof(type); size -= sizeof(type); }

/* Convert and output the sample. */
if (samples_signed) {
if (sample_size == 1) {
if (stream->out_samples_signed) {
if (stream->out_sample_size == 1) {
OUTPUT_SAMPLE(gint8, current_sample * G_MAXINT8);
} else if (!byteswap_needed) {
} else if (!stream->byteswap_needed) {
OUTPUT_SAMPLE(gint16, current_sample * G_MAXINT16);
} else {
OUTPUT_SAMPLE(guint16, GUINT16_SWAP_LE_BE((guint16)(gint16)(current_sample * G_MAXINT16)));
}
} else {
current_sample = (float)(current_sample * 0.5 + 0.5);
if (sample_size == 1) {
if (stream->out_sample_size == 1) {
OUTPUT_SAMPLE(guint8, current_sample * G_MAXUINT8);
} else if (!byteswap_needed) {
} else if (!stream->byteswap_needed) {
OUTPUT_SAMPLE(guint16, current_sample * G_MAXUINT16);
} else {
OUTPUT_SAMPLE(guint16, GUINT16_SWAP_LE_BE((guint16)(current_sample * G_MAXUINT16)));
}
}

/* If we're converting mono to stereo, duplicate the sample. */
if (stream->channels == 1 && out_channels == 2) {
if (sample_size == 1) {
if (stream->channels == 1 && stream->out_channels == 2) {
if (stream->out_sample_size == 1) {
OUTPUT_SAMPLE(guint8, *(guint8*)(out_buf - sizeof(guint8)));
} else {
OUTPUT_SAMPLE(guint16, *(guint16*)(out_buf - sizeof(guint16)));
Expand Down

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