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Diffstat (limited to 'src/pcm_convert.c')
| -rw-r--r-- | src/pcm_convert.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/src/pcm_convert.c b/src/pcm_convert.c new file mode 100644 index 000000000..283befd8c --- /dev/null +++ b/src/pcm_convert.c @@ -0,0 +1,157 @@ +/* + * Copyright (C) 2003-2009 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include "pcm_convert.h" +#include "pcm_channels.h" +#include "pcm_format.h" +#include "audio_format.h" + +#include <assert.h> +#include <string.h> +#include <math.h> +#include <glib.h> + +#undef G_LOG_DOMAIN +#define G_LOG_DOMAIN "pcm" + +void pcm_convert_init(struct pcm_convert_state *state) +{ + memset(state, 0, sizeof(*state)); + + pcm_resample_init(&state->resample); + pcm_dither_24_init(&state->dither); +} + +static size_t +pcm_convert_16(const struct audio_format *src_format, + const void *src_buffer, size_t src_size, + const struct audio_format *dest_format, + int16_t *dest_buffer, + struct pcm_convert_state *state) +{ + const int16_t *buf; + size_t len; + size_t dest_size = pcm_convert_size(src_format, src_size, dest_format); + + assert(dest_format->bits == 16); + + buf = pcm_convert_to_16(&state->dither, src_format->bits, + src_buffer, src_size, &len); + if (!buf) + g_error("pcm_convert_to_16() failed"); + + if (src_format->channels != dest_format->channels) { + buf = pcm_convert_channels_16(dest_format->channels, + src_format->channels, + buf, len, &len); + if (!buf) + g_error("pcm_convert_channels_16() failed"); + } + + if (src_format->sample_rate == dest_format->sample_rate) { + assert(dest_size >= len); + memcpy(dest_buffer, buf, len); + } else { + len = pcm_resample_16(dest_format->channels, + src_format->sample_rate, buf, len, + dest_format->sample_rate, + dest_buffer, dest_size, + &state->resample); + } + + return len; +} + +static size_t +pcm_convert_24(const struct audio_format *src_format, + const void *src_buffer, size_t src_size, + const struct audio_format *dest_format, + int32_t *dest_buffer, + struct pcm_convert_state *state) +{ + const int32_t *buf; + size_t len; + size_t dest_size = pcm_convert_size(src_format, src_size, dest_format); + + assert(dest_format->bits == 24); + + buf = pcm_convert_to_24(src_format->bits, + src_buffer, src_size, &len); + if (!buf) + g_error("pcm_convert_to_24() failed"); + + if (src_format->channels != dest_format->channels) { + buf = pcm_convert_channels_24(dest_format->channels, + src_format->channels, + buf, len, &len); + if (!buf) + g_error("pcm_convert_channels_24() failed"); + } + + if (src_format->sample_rate == dest_format->sample_rate) { + assert(dest_size >= len); + memcpy(dest_buffer, buf, len); + } else { + len = pcm_resample_24(dest_format->channels, + src_format->sample_rate, buf, len, + dest_format->sample_rate, + (int32_t*)dest_buffer, dest_size, + &state->resample); + } + + return len; +} + +/* outFormat bits must be 16 and channels must be 1 or 2! */ +size_t pcm_convert(const struct audio_format *inFormat, + const char *src, size_t src_size, + const struct audio_format *outFormat, + char *outBuffer, + struct pcm_convert_state *convState) +{ + switch (outFormat->bits) { + case 16: + return pcm_convert_16(inFormat, src, src_size, + outFormat, (int16_t*)outBuffer, + convState); + case 24: + return pcm_convert_24(inFormat, src, src_size, + outFormat, (int32_t*)outBuffer, + convState); + + default: + g_error("cannot convert to %u bit\n", outFormat->bits); + } +} + +size_t pcm_convert_size(const struct audio_format *inFormat, size_t src_size, + const struct audio_format *outFormat) +{ + const double ratio = (double)outFormat->sample_rate / + (double)inFormat->sample_rate; + size_t dest_size = src_size; + + /* no partial frames allowed */ + assert((src_size % audio_format_frame_size(inFormat)) == 0); + + dest_size /= audio_format_frame_size(inFormat); + dest_size = ceil((double)dest_size * ratio); + dest_size *= audio_format_frame_size(outFormat); + + return dest_size; +} |