diff options
Diffstat (limited to 'src/pcm_export.c')
| -rw-r--r-- | src/pcm_export.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/src/pcm_export.c b/src/pcm_export.c new file mode 100644 index 000000000..144ac71cd --- /dev/null +++ b/src/pcm_export.c @@ -0,0 +1,160 @@ +/* + * Copyright (C) 2003-2012 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 "pcm_export.h" +#include "pcm_dsd_usb.h" +#include "pcm_pack.h" +#include "util/byte_reverse.h" + +void +pcm_export_init(struct pcm_export_state *state) +{ + pcm_buffer_init(&state->reverse_buffer); + pcm_buffer_init(&state->pack_buffer); + pcm_buffer_init(&state->dsd_buffer); +} + +void pcm_export_deinit(struct pcm_export_state *state) +{ + pcm_buffer_deinit(&state->reverse_buffer); + pcm_buffer_deinit(&state->pack_buffer); + pcm_buffer_deinit(&state->dsd_buffer); +} + +void +pcm_export_open(struct pcm_export_state *state, + enum sample_format sample_format, unsigned channels, + bool dsd_usb, bool shift8, bool pack, bool reverse_endian) +{ + assert(audio_valid_sample_format(sample_format)); + assert(!dsd_usb || audio_valid_channel_count(channels)); + + state->channels = channels; + state->dsd_usb = dsd_usb && sample_format == SAMPLE_FORMAT_DSD; + if (state->dsd_usb) + /* after the conversion to DSD-over-USB, the DSD + samples are stuffed inside fake 24 bit samples */ + sample_format = SAMPLE_FORMAT_S24_P32; + + state->shift8 = shift8 && sample_format == SAMPLE_FORMAT_S24_P32; + state->pack24 = pack && sample_format == SAMPLE_FORMAT_S24_P32; + + assert(!state->shift8 || !state->pack24); + + state->reverse_endian = 0; + if (reverse_endian) { + size_t sample_size = state->pack24 + ? 3 + : sample_format_size(sample_format); + assert(sample_size <= 0xff); + + if (sample_size > 1) + state->reverse_endian = sample_size; + } +} + +size_t +pcm_export_frame_size(const struct pcm_export_state *state, + const struct audio_format *audio_format) +{ + assert(state != NULL); + assert(audio_format != NULL); + + if (state->pack24) + /* packed 24 bit samples (3 bytes per sample) */ + return audio_format->channels * 3; + + if (state->dsd_usb) + /* the DSD-over-USB draft says that DSD 1-bit samples + are enclosed within 24 bit samples, and MPD's + representation of 24 bit is padded to 32 bit (4 + bytes per sample) */ + return audio_format->channels * 4; + + return audio_format_frame_size(audio_format); +} + +const void * +pcm_export(struct pcm_export_state *state, const void *data, size_t size, + size_t *dest_size_r) +{ + if (state->dsd_usb) + data = pcm_dsd_to_usb(&state->dsd_buffer, state->channels, + data, size, &size); + + if (state->pack24) { + assert(size % 4 == 0); + + const size_t num_samples = size / 4; + const size_t dest_size = num_samples * 3; + + const uint8_t *src8 = data, *src_end8 = src8 + size; + uint8_t *dest = pcm_buffer_get(&state->pack_buffer, dest_size); + assert(dest != NULL); + + pcm_pack_24(dest, (const int32_t *)src8, + (const int32_t *)src_end8); + + data = dest; + size = dest_size; + } else if (state->shift8) { + assert(size % 4 == 0); + + const uint8_t *src8 = data, *src_end8 = src8 + size; + const uint32_t *src = (const uint32_t *)src8; + const uint32_t *const src_end = (const uint32_t *)src_end8; + + uint32_t *dest = pcm_buffer_get(&state->pack_buffer, size); + data = dest; + + while (src < src_end) + *dest++ = *src++ << 8; + } + + + if (state->reverse_endian > 0) { + assert(state->reverse_endian >= 2); + + void *dest = pcm_buffer_get(&state->reverse_buffer, size); + assert(dest != NULL); + + const uint8_t *src = data, *src_end = src + size; + reverse_bytes(dest, src, src_end, state->reverse_endian); + + data = dest; + } + + *dest_size_r = size; + return data; +} + +size_t +pcm_export_source_size(const struct pcm_export_state *state, size_t size) +{ + if (state->pack24) + /* 32 bit to 24 bit conversion (4 to 3 bytes) */ + size = (size / 3) * 4; + + if (state->dsd_usb) + /* DSD over USB doubles the transport size */ + size /= 2; + + return size; +} |