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Diffstat (limited to 'src/PcmChannels.cxx')
| -rw-r--r-- | src/PcmChannels.cxx | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/src/PcmChannels.cxx b/src/PcmChannels.cxx new file mode 100644 index 00000000..eca6b250 --- /dev/null +++ b/src/PcmChannels.cxx @@ -0,0 +1,290 @@ +/* + * Copyright (C) 2003-2013 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "config.h" +#include "PcmChannels.hxx" +#include "pcm_buffer.h" +#include "PcmUtils.hxx" + +#include <assert.h> + +template<typename D, typename S> +static void +MonoToStereo(D dest, S src, S end) +{ + while (src != end) { + const auto value = *src++; + + *dest++ = value; + *dest++ = value; + } + +} + +static void +pcm_convert_channels_16_2_to_1(int16_t *restrict dest, + const int16_t *restrict src, + const int16_t *restrict src_end) +{ + while (src < src_end) { + int32_t a = *src++, b = *src++; + + *dest++ = (a + b) / 2; + } +} + +static void +pcm_convert_channels_16_n_to_2(int16_t *restrict dest, + unsigned src_channels, + const int16_t *restrict src, + const int16_t *restrict src_end) +{ + unsigned c; + + assert(src_channels > 0); + + while (src < src_end) { + int32_t sum = 0; + int16_t value; + + for (c = 0; c < src_channels; ++c) + sum += *src++; + value = sum / (int)src_channels; + + /* XXX this is actually only mono ... */ + *dest++ = value; + *dest++ = value; + } +} + +const int16_t * +pcm_convert_channels_16(struct pcm_buffer *buffer, + unsigned dest_channels, + unsigned src_channels, const int16_t *src, + size_t src_size, size_t *dest_size_r) +{ + assert(src_size % (sizeof(*src) * src_channels) == 0); + + size_t dest_size = src_size / src_channels * dest_channels; + *dest_size_r = dest_size; + + int16_t *dest = (int16_t *)pcm_buffer_get(buffer, dest_size); + const int16_t *src_end = pcm_end_pointer(src, src_size); + + if (src_channels == 1 && dest_channels == 2) + MonoToStereo(dest, src, src_end); + else if (src_channels == 2 && dest_channels == 1) + pcm_convert_channels_16_2_to_1(dest, src, src_end); + else if (dest_channels == 2) + pcm_convert_channels_16_n_to_2(dest, src_channels, src, + src_end); + else + return NULL; + + return dest; +} + +static void +pcm_convert_channels_24_2_to_1(int32_t *restrict dest, + const int32_t *restrict src, + const int32_t *restrict src_end) +{ + while (src < src_end) { + int32_t a = *src++, b = *src++; + + *dest++ = (a + b) / 2; + } +} + +static void +pcm_convert_channels_24_n_to_2(int32_t *restrict dest, + unsigned src_channels, + const int32_t *restrict src, + const int32_t *restrict src_end) +{ + unsigned c; + + assert(src_channels > 0); + + while (src < src_end) { + int32_t sum = 0; + int32_t value; + + for (c = 0; c < src_channels; ++c) + sum += *src++; + value = sum / (int)src_channels; + + /* XXX this is actually only mono ... */ + *dest++ = value; + *dest++ = value; + } +} + +const int32_t * +pcm_convert_channels_24(struct pcm_buffer *buffer, + unsigned dest_channels, + unsigned src_channels, const int32_t *src, + size_t src_size, size_t *dest_size_r) +{ + assert(src_size % (sizeof(*src) * src_channels) == 0); + + size_t dest_size = src_size / src_channels * dest_channels; + *dest_size_r = dest_size; + + int32_t *dest = (int32_t *)pcm_buffer_get(buffer, dest_size); + const int32_t *src_end = (const int32_t *) + pcm_end_pointer(src, src_size); + + if (src_channels == 1 && dest_channels == 2) + MonoToStereo(dest, src, src_end); + else if (src_channels == 2 && dest_channels == 1) + pcm_convert_channels_24_2_to_1(dest, src, src_end); + else if (dest_channels == 2) + pcm_convert_channels_24_n_to_2(dest, src_channels, src, + src_end); + else + return NULL; + + return dest; +} + +static void +pcm_convert_channels_32_2_to_1(int32_t *restrict dest, + const int32_t *restrict src, + const int32_t *restrict src_end) +{ + while (src < src_end) { + int64_t a = *src++, b = *src++; + + *dest++ = (a + b) / 2; + } +} + +static void +pcm_convert_channels_32_n_to_2(int32_t *dest, + unsigned src_channels, const int32_t *src, + const int32_t *src_end) +{ + unsigned c; + + assert(src_channels > 0); + + while (src < src_end) { + int64_t sum = 0; + int32_t value; + + for (c = 0; c < src_channels; ++c) + sum += *src++; + value = sum / (int64_t)src_channels; + + /* XXX this is actually only mono ... */ + *dest++ = value; + *dest++ = value; + } +} + +const int32_t * +pcm_convert_channels_32(struct pcm_buffer *buffer, + unsigned dest_channels, + unsigned src_channels, const int32_t *src, + size_t src_size, size_t *dest_size_r) +{ + assert(src_size % (sizeof(*src) * src_channels) == 0); + + size_t dest_size = src_size / src_channels * dest_channels; + *dest_size_r = dest_size; + + int32_t *dest = (int32_t *)pcm_buffer_get(buffer, dest_size); + const int32_t *src_end = (const int32_t *) + pcm_end_pointer(src, src_size); + + if (src_channels == 1 && dest_channels == 2) + MonoToStereo(dest, src, src_end); + else if (src_channels == 2 && dest_channels == 1) + pcm_convert_channels_32_2_to_1(dest, src, src_end); + else if (dest_channels == 2) + pcm_convert_channels_32_n_to_2(dest, src_channels, src, + src_end); + else + return NULL; + + return dest; +} + +static void +pcm_convert_channels_float_2_to_1(float *restrict dest, + const float *restrict src, + const float *restrict src_end) +{ + while (src < src_end) { + double a = *src++, b = *src++; + + *dest++ = (a + b) / 2; + } +} + +static void +pcm_convert_channels_float_n_to_2(float *dest, + unsigned src_channels, const float *src, + const float *src_end) +{ + unsigned c; + + assert(src_channels > 0); + + while (src < src_end) { + double sum = 0; + float value; + + for (c = 0; c < src_channels; ++c) + sum += *src++; + value = sum / (double)src_channels; + + /* XXX this is actually only mono ... */ + *dest++ = value; + *dest++ = value; + } +} + +const float * +pcm_convert_channels_float(struct pcm_buffer *buffer, + unsigned dest_channels, + unsigned src_channels, const float *src, + size_t src_size, size_t *dest_size_r) +{ + assert(src_size % (sizeof(*src) * src_channels) == 0); + + size_t dest_size = src_size / src_channels * dest_channels; + *dest_size_r = dest_size; + + float *dest = (float *)pcm_buffer_get(buffer, dest_size); + const float *src_end = (const float *)pcm_end_pointer(src, src_size); + + if (src_channels == 1 && dest_channels == 2) + MonoToStereo(dest, src, src_end); + else if (src_channels == 2 && dest_channels == 1) + pcm_convert_channels_float_2_to_1(dest, src, src_end); + else if (dest_channels == 2) + pcm_convert_channels_float_n_to_2(dest, src_channels, src, + src_end); + else + return NULL; + + return dest; +} |