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Diffstat (limited to 'src/pcm_export.h')
-rw-r--r-- | src/pcm_export.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/src/pcm_export.h b/src/pcm_export.h new file mode 100644 index 000000000..418dcdfa3 --- /dev/null +++ b/src/pcm_export.h @@ -0,0 +1,139 @@ +/* + * 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. + */ + +#ifndef PCM_EXPORT_H +#define PCM_EXPORT_H + +#include "check.h" +#include "pcm_buffer.h" +#include "audio_format.h" + +#include <stdbool.h> + +struct audio_format; + +/** + * An object that handles export of PCM samples to some instance + * outside of MPD. It has a few more options to tweak the binary + * representation which are not supported by the pcm_convert library. + */ +struct pcm_export_state { + /** + * The buffer is used to convert DSD samples to the + * DSD-over-USB format. + * + * @see #dsd_usb + */ + struct pcm_buffer dsd_buffer; + + /** + * The buffer is used to pack samples, removing padding. + * + * @see #pack24 + */ + struct pcm_buffer pack_buffer; + + /** + * The buffer is used to reverse the byte order. + * + * @see #reverse_endian + */ + struct pcm_buffer reverse_buffer; + + /** + * The number of channels. + */ + uint8_t channels; + + /** + * Convert DSD to DSD-over-USB? Input format must be + * SAMPLE_FORMAT_DSD and output format must be + * SAMPLE_FORMAT_S24_P32. + */ + bool dsd_usb; + + /** + * Convert (padded) 24 bit samples to 32 bit by shifting 8 + * bits to the left? + */ + bool shift8; + + /** + * Pack 24 bit samples? + */ + bool pack24; + + /** + * Export the samples in reverse byte order? A non-zero value + * means the option is enabled and represents the size of each + * sample (2 or bigger). + */ + uint8_t reverse_endian; +}; + +/** + * Initialize a #pcm_export_state object. + */ +void +pcm_export_init(struct pcm_export_state *state); + +/** + * Deinitialize a #pcm_export_state object and free allocated memory. + */ +void +pcm_export_deinit(struct pcm_export_state *state); + +/** + * Open the #pcm_export_state object. + * + * There is no "close" method. This function may be called multiple + * times to reuse the object, until pcm_export_deinit() is called. + * + * This function cannot fail. + * + * @param channels the number of channels; ignored unless dsd_usb is set + */ +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); + +/** + * Export a PCM buffer. + * + * @param state an initialized and open pcm_export_state object + * @param src the source PCM buffer + * @param src_size the size of #src in bytes + * @param dest_size_r returns the number of bytes of the destination buffer + * @return the destination buffer (may be a pointer to the source buffer) + */ +const void * +pcm_export(struct pcm_export_state *state, const void *src, size_t src_size, + size_t *dest_size_r); + +/** + * Converts the number of consumed bytes from the pcm_export() + * destination buffer to the according number of bytes from the + * pcm_export() source buffer. + */ +G_GNUC_PURE +size_t +pcm_export_source_size(const struct pcm_export_state *state, size_t dest_size); + +#endif |