From 5398125fb30bf4326b29b5a7207ec0a517f09ff0 Mon Sep 17 00:00:00 2001 From: Michael Sevakis Date: Fri, 16 Nov 2007 14:26:05 +0000 Subject: [PATCH] Use sized data types for audio data in the pcm buffer. Speed up the clipping routine. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15636 a1c6a512-1295-4272-9138-f99709370657 --- apps/pcmbuf.c | 78 ++++++++++++++++++++++++++++----------------------- 1 file changed, 43 insertions(+), 35 deletions(-) diff --git a/apps/pcmbuf.c b/apps/pcmbuf.c index a6b82baf25..1a2324baaf 100644 --- a/apps/pcmbuf.c +++ b/apps/pcmbuf.c @@ -42,6 +42,14 @@ #define PCMBUF_MUTING #endif +/* Clip sample to signed 16 bit range */ +static inline int32_t clip_sample_16(int32_t sample) +{ + if ((int16_t)sample != sample) + sample = 0x7fff ^ (sample >> 31); + return sample; +} + /* Keep watermark high for iPods at least (2s) */ #define PCMBUF_WATERMARK (NATIVE_FREQUENCY * 4 * 2) @@ -564,8 +572,8 @@ static void crossfade_process_buffer(size_t fade_in_delay, while (block_rem > 0 && fade_out_chunk != NULL) { /* Fade one sample */ - short *buf = (short *)(fade_out_chunk->addr); - int sample = buf[fade_out_sample]; + int16_t *buf = (int16_t *)fade_out_chunk->addr; + int32_t sample = buf[fade_out_sample]; buf[fade_out_sample++] = (sample * factor) >> 8; block_rem -= 2; @@ -665,16 +673,16 @@ static void crossfade_start(void) /* Returns the number of bytes _NOT_ mixed */ static size_t crossfade_fade_mix(int factor, const char *buf, size_t fade_rem) { - const short *input_buf = (const short *)buf; - short *output_buf = (short *)(crossfade_chunk->addr); - short *chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size); + const int16_t *input_buf = (const int16_t *)buf; + int16_t *output_buf = (int16_t *)(crossfade_chunk->addr); + int16_t *chunk_end = SKIPBYTES(output_buf, crossfade_chunk->size); output_buf = &output_buf[crossfade_sample]; while (fade_rem) { int sample = *input_buf++; sample = ((sample * factor) >> 8) + *output_buf; - *output_buf++ = MIN(32767, MAX(-32768, sample)); + *output_buf++ = clip_sample_16(sample); fade_rem -= 2; if (output_buf >= chunk_end) @@ -682,26 +690,26 @@ static size_t crossfade_fade_mix(int factor, const char *buf, size_t fade_rem) crossfade_chunk = crossfade_chunk->link; if (!crossfade_chunk) return fade_rem; - output_buf = (short *)(crossfade_chunk->addr); - chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size); + output_buf = (int16_t *)crossfade_chunk->addr; + chunk_end = SKIPBYTES(output_buf, crossfade_chunk->size); } } - crossfade_sample = (size_t)(output_buf - (short *)(crossfade_chunk->addr)); + crossfade_sample = output_buf - (int16_t *)crossfade_chunk->addr; return 0; } /* Returns the number of bytes _NOT_ mixed */ static size_t crossfade_mix(const char *buf, size_t length) { - const short *input_buf = (const short *)buf; - short *output_buf = (short *)(crossfade_chunk->addr); - short *chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size); + const int16_t *input_buf = (const int16_t *)buf; + int16_t *output_buf = (int16_t *)crossfade_chunk->addr; + int16_t *chunk_end = SKIPBYTES(output_buf, crossfade_chunk->size); output_buf = &output_buf[crossfade_sample]; while (length) { int sample = *input_buf++ + *output_buf; - *output_buf++ = MIN(32767, MAX(-32768, sample)); + *output_buf++ = clip_sample_16(sample); length -= 2; if (output_buf >= chunk_end) @@ -709,11 +717,11 @@ static size_t crossfade_mix(const char *buf, size_t length) crossfade_chunk = crossfade_chunk->link; if (!crossfade_chunk) return length; - output_buf = (short *)(crossfade_chunk->addr); - chunk_end = (short *)((size_t)output_buf + crossfade_chunk->size); + output_buf = (int16_t *)(crossfade_chunk->addr); + chunk_end = SKIPBYTES(output_buf, crossfade_chunk->size); } } - crossfade_sample = (size_t)(output_buf - (short *)(crossfade_chunk->addr)); + crossfade_sample = output_buf - (int16_t *)crossfade_chunk->addr; return 0; } @@ -742,7 +750,7 @@ static void flush_crossfade(char *buf, size_t length) if (crossfade_fade_in_rem) { size_t samples; - short *input_buf; + int16_t *input_buf; /* Fade factor for this packet */ int factor = @@ -768,11 +776,11 @@ static void flush_crossfade(char *buf, size_t length) } samples = fade_rem / 2; - input_buf = (short *)buf; + input_buf = (int16_t *)buf; /* Fade remaining samples in place */ while (samples) { - int sample = *input_buf; + int32_t sample = *input_buf; *input_buf++ = (sample * factor) >> 8; samples--; } @@ -940,9 +948,9 @@ void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude) { unsigned int count = 0, i = 0; unsigned int interval = NATIVE_FREQUENCY / frequency; - long sample; - short *buf; - short *pcmbuf_end = (short *)fadebuf; + int32_t sample; + int16_t *buf; + int16_t *pcmbuf_end = (int16_t *)fadebuf; size_t samples = NATIVE_FREQUENCY / 1000 * duration; if (pcm_is_playing() && pcmbuf_read != NULL) @@ -952,7 +960,7 @@ void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude) /* Get the next chunk */ char *pcmbuf_mix_buf = pcmbuf_read->link->addr; /* Give at least 1/8s clearance. */ - buf = (short *)&pcmbuf_mix_buf[NATIVE_FREQUENCY * 4 / 8]; + buf = (int16_t *)&pcmbuf_mix_buf[NATIVE_FREQUENCY * 4 / 8]; } else { @@ -963,11 +971,11 @@ void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude) while (i++ < samples) { sample = *buf; - *buf++ = MIN(MAX(sample + amplitude, -32768), 32767); + *buf++ = clip_sample_16(sample + amplitude); if (buf > pcmbuf_end) - buf = (short *)audiobuffer; + buf = (int16_t *)audiobuffer; sample = *buf; - *buf++ = MIN(MAX(sample + amplitude, -32768), 32767); + *buf++ = clip_sample_16(sample + amplitude); /* Toggle square wav side */ if (++count >= interval) @@ -976,17 +984,17 @@ void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude) amplitude = -amplitude; } if (buf > pcmbuf_end) - buf = (short *)audiobuffer; + buf = (int16_t *)audiobuffer; } } else { - buf = (short *)audiobuffer; + buf = (int16_t *)audiobuffer; while (i++ < samples) { *buf++ = amplitude; if (buf > pcmbuf_end) - buf = (short *)audiobuffer; + buf = (int16_t *)audiobuffer; *buf++ = amplitude; /* Toggle square wav side */ @@ -996,7 +1004,7 @@ void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude) amplitude = -amplitude; } if (buf > pcmbuf_end) - buf = (short *)audiobuffer; + buf = (int16_t *)audiobuffer; } pcm_play_data(NULL, (unsigned char *)audiobuffer, samples * 4); } @@ -1013,7 +1021,7 @@ int pcmbuf_mix_free(void) if (pcmbuf_mix_chunk) { size_t my_mix_end = - (size_t)&((short *)pcmbuf_mix_chunk->addr)[pcmbuf_mix_sample]; + (size_t)&((int16_t *)pcmbuf_mix_chunk->addr)[pcmbuf_mix_sample]; size_t my_write_pos = (size_t)&audiobuffer[audiobuffer_pos]; if (my_write_pos < my_mix_end) my_write_pos += pcmbuf_size; @@ -1024,8 +1032,8 @@ int pcmbuf_mix_free(void) void pcmbuf_mix_voice(int count) { - short *ibuf = (short *)voicebuf; - short *obuf; + int16_t *ibuf = (int16_t *)voicebuf; + int16_t *obuf; size_t chunk_samples; if (pcmbuf_mix_chunk == NULL && pcmbuf_read != NULL) @@ -1037,7 +1045,7 @@ void pcmbuf_mix_voice(int count) if (!pcmbuf_mix_chunk) return; - obuf = (short *)pcmbuf_mix_chunk->addr; + obuf = (int16_t *)pcmbuf_mix_chunk->addr; chunk_samples = pcmbuf_mix_chunk->size / 2; count <<= 1; @@ -1054,7 +1062,7 @@ void pcmbuf_mix_voice(int count) chunk_samples = pcmbuf_mix_chunk->size / 2; } sample += obuf[pcmbuf_mix_sample] >> 2; - obuf[pcmbuf_mix_sample++] = MIN(MAX(sample, -32768), 32767); + obuf[pcmbuf_mix_sample++] = clip_sample_16(sample); } }