gstreamer/subprojects/gst-plugins-base/gst-libs/gst/audio/gstdsd.h
Edward Hervey 654609ef15 dsd: Fix documentation parameters
There were some inconsistencies between documentation and function signatures

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5002>
2023-07-11 05:17:55 +00:00

338 lines
12 KiB
C

/* GStreamer
* Copyright (C) 2023 Carlos Rafael Giani <crg7475@mailbox.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#pragma once
#include <gst/gst.h>
#include <gst/audio/audio.h>
#include <gst/audio/gstdsdformat.h>
G_BEGIN_DECLS
/**
* GST_DSD_MEDIA_TYPE:
*
* The GStreamer media type for DSD.
*
* Since: 1.24
*/
#define GST_DSD_MEDIA_TYPE "audio/x-dsd"
/**
* GST_DSD_CAPS_MAKE:
* @format: string format that describes the DSD bits grouping,
* as string (e.g. "DSDU32BE", "DSDU8", etc.)
*
* Generic caps string for DSD audio, for use in pad templates.
*
* Since: 1.24
*/
#define GST_DSD_CAPS_MAKE(format) \
GST_DSD_MEDIA_TYPE ", " \
"format = (string) " format ", " \
"rate = " GST_AUDIO_RATE_RANGE ", " \
"layout = (string) { interleaved, non-interleaved }, " \
"reversed-bytes = (gboolean) { false, true }, " \
"channels = " GST_AUDIO_CHANNELS_RANGE
/**
* GST_DSD_MAKE_DSD_RATE_44x:
*
* Calculates a valid DSD-44x rate (in bytes) from commonly used rate
* multiplier specifications like DSD64, DSD128 etc.
*
* For example, to get the rate for DSD64-44x, use 64 as the multiplier
* argument.
*
* Since: 1.24
*/
#define GST_DSD_MAKE_DSD_RATE_44x(multiplier) \
((gint) ((gint64) multiplier) * 44100 / 8)
/**
* GST_DSD_MAKE_DSD_RATE_48x:
*
* Calculates a valid DSD-48x rate (in bytes) from commonly used rate
* multiplier specifications like DSD64, DSD128 etc.
*
* For example, to get the rate for DSD64-48x, use 64 as the multiplier
* argument.
*
* Since: 1.24
*/
#define GST_DSD_MAKE_DSD_RATE_48x(multiplier) \
((gint) ((gint64) multiplier) * 48000 / 8)
/**
* GST_DSD_SILENCE_PATTERN_BYTE:
*
* Silence pattern for DSD data.
*
* In DSD, a nullbyte does not correspond to silence. To fill memory regions
* with "DSD silence", these regions must be filled with byte 0x69 instead
* (this is the DSD silence pattern). This constant provides that pattern
* in a more readable fashion.
*
* Since: 1.24
*/
#define GST_DSD_SILENCE_PATTERN_BYTE (0x69)
typedef struct _GstDsdInfo GstDsdInfo;
/**
* GstDsdInfo:
* @format: DSD grouping format
* @rate: DSD rate
* @channels: number of channels (must be at least 1)
* @layout: audio layout
* @reversed_bytes: true if the DSD bits in the data bytes are reversed,
* that is, the least significant bit comes first
* @positions: positions for each channel
*
* Information describing DSD audio properties.
*
* In DSD, the "sample format" is the bit. Unlike PCM, there are no further
* "sample formats" in DSD. However, in software, DSD bits are grouped into
* bytes (since dealing with individual bits is impractical), and these bytes
* in turn are grouped into words. This becomes relevant when interleaving
* channels and transmitting DSD data through audio APIs. The different
* types of grouping DSD bytes are referred to as the "DSD grouping forma"
* or just "DSD format". #GstDsdFormat has a list of valid ways of grouping
* DSD bytes into words.
*
* DSD rates are equivalent to PCM sample rates, except that they specify
* how many DSD bytes are consumed per second. This refers to the bytes per
* second _per channel_; the rate does not change when the number of channel
* changes. (Strictly speaking, it would be more correct to measure the
* *bits* per second, since the bit is the DSD "sample format", but it is
* more practical to use bytes.) In DSD, bit rates are always an integer
* multiple of the CD audio rate (44100) or the DAT rate (48000). DSD64-44x
* is 44100 * 64 = 2822400 bits per second, or 352800 bytes per second
* (the latter would be used in this info structure). DSD64-48x is
* 48000 * 64 = 3072000 bits per second, or 384000 bytes per second.
* #GST_DSD_MAKE_DSD_RATE_44x can be used for specifying DSD-44x rates,
* *and #GST_DSD_MAKE_DSD_RATE_48x can be used for specifying DSD-48x ones.
* Also, since DSD-48x is less well known, when the multiplier is given
* without the 44x/48x specifier, 44x is typically implied.
*
* It is important to know that in DSD, different format widths correspond
* to different playtimes. That is, a word with 32 DSD bits covers two times
* as much playtime as a word with 16 DSD bits. This is in contrast to PCM,
* where one word (= one PCM sample) always covers a time period of 1/samplerate,
* no matter how many bits a PCM sample is made of. For this reason, DSD
* and PCM widths and strides cannot be used the same way.
*
* Multiple channels are arranged in DSD data either interleaved or non-
* interleaved. This is similar to PCM. Interleaved layouts rotate between
* channels and words. First, word 0 of channel 0 is present. Then word
* 0 of channel 1 follows. Then word 0 of channel 2 etc. until all
* channels are through, then comes word 1 of channel 0 etc.
*
* Non-interleaved data is planar. First, all words of channel 0 are
* present, then all words of channel 1 etc. Unlike interleaved data,
* non-interleaved data can be sparse, that is, there can be space in
* between the planes. the @positions array specifies the plane offsets.
*
* In uncommon cases, the DSD bits in the data bytes can be stored in reverse
* order. For example, normally, in DSDU8, the first byte contains DSD bits
* 0 to 7, and the most significant bit of that byte is DSD bit 0. If this
* order is reversed, then bit 7 is the first one instead. In that ase,
* @reversed_bytes is set to TRUE.
*
* Use the provided macros to access the info in this structure.
*
* Since: 1.24
*/
struct _GstDsdInfo {
GstDsdFormat format;
gint rate;
gint channels;
GstAudioLayout layout;
gboolean reversed_bytes;
GstAudioChannelPosition positions[64];
GstAudioFlags flags;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
#define GST_TYPE_DSD_INFO (gst_dsd_info_get_type ())
GST_AUDIO_API
GType gst_dsd_info_get_type (void);
#define GST_DSD_INFO_IS_VALID(i) ((i)->format < GST_NUM_DSD_FORMATS && (i)->rate > 0 && (i)->channels > 0)
#define GST_DSD_INFO_FORMAT(info) ((info)->format)
#define GST_DSD_INFO_RATE(info) ((info)->rate)
#define GST_DSD_INFO_CHANNELS(info) ((info)->channels)
#define GST_DSD_INFO_LAYOUT(info) ((info)->layout)
#define GST_DSD_INFO_REVERSED_BYTES(info) ((info)->reversed_bytes)
#define GST_DSD_INFO_POSITION(info,c) ((info)->position[c])
/**
* GST_DSD_INFO_STRIDE:
*
* Calculates the stride for a given #GstDsdInfo.
*
* Note that this is only useful if the info's audio layout
* is GST_AUDIO_LAYOUT_INTERLEAVED.
*
* Since: 1.24
*/
#define GST_DSD_INFO_STRIDE(info) (gst_dsd_format_get_width((info)->format) * (info)->channels)
/*** GstDsdPlaneOffsetMeta ***/
#define GST_DSD_PLANE_OFFSET_META_API_TYPE (gst_dsd_plane_offset_meta_api_get_type())
#define GST_DSD_PLANE_OFFSET_META_INFO (gst_dsd_plane_offset_meta_get_info())
/**
* GST_META_TAG_DSD_PLANE_OFFSETS_STR:
*
* This metadata stays relevant as long as the DSD plane offsets are unchanged.
*
* Since: 1.24
*/
#define GST_META_TAG_DSD_PLANE_OFFSETS_STR "dsdplaneoffsets"
typedef struct _GstDsdPlaneOffsetMeta GstDsdPlaneOffsetMeta;
/**
* GstDsdPlaneOffsetMeta:
* @meta: parent #GstMeta
* @num_channels: number of channels in the DSD data
* @num_bytes_per_channel: the number of valid bytes per channel in the buffer
* @offsets: the offsets (in bytes) where each channel plane starts in the buffer
*
* Buffer metadata describing planar DSD contents in the buffer. This is not needed
* for interleaved DSD data, and is required for non-interleaved (= planar) data.
*
* The different channels in @offsets are always in the GStreamer channel order.
* Zero-copy channel reordering can be implemented by swapping the values in
* @offsets.
*
* It is not allowed for channels to overlap in memory,
* i.e. for each i in [0, channels), the range
* [@offsets[i], @offsets[i] + @num_bytes_per_channel) must not overlap
* with any other such range.
*
* It is, however, allowed to have parts of the buffer memory unused, by using
* @offsets and @num_bytes_per_channel in such a way that leave gaps on it.
* This is used to implement zero-copy clipping in non-interleaved buffers.
*
* Obviously, due to the above, it is not safe to infer the
* number of valid bytes from the size of the buffer. You should always
* use the @num_bytes_per_channel variable of this metadata.
*
* Since: 1.24
*/
struct _GstDsdPlaneOffsetMeta {
GstMeta meta;
gint num_channels;
gsize num_bytes_per_channel;
gsize *offsets;
/*< private >*/
gsize priv_offsets_arr[8];
gpointer _gst_reserved[GST_PADDING];
};
GST_AUDIO_API
GType gst_dsd_plane_offset_meta_api_get_type (void);
GST_AUDIO_API
const GstMetaInfo * gst_dsd_plane_offset_meta_get_info (void);
#define gst_buffer_get_dsd_plane_offset_meta(b) \
((GstDsdPlaneOffsetMeta*)gst_buffer_get_meta((b), GST_DSD_PLANE_OFFSET_META_API_TYPE))
GST_AUDIO_API
GstDsdPlaneOffsetMeta * gst_buffer_add_dsd_plane_offset_meta (GstBuffer *buffer,
gint num_channels,
gsize num_bytes_per_channel,
gsize offsets[]);
GST_AUDIO_API
GstDsdInfo * gst_dsd_info_new (void);
GST_AUDIO_API
GstDsdInfo * gst_dsd_info_new_from_caps (const GstCaps * caps);
GST_AUDIO_API
void gst_dsd_info_init (GstDsdInfo * info);
GST_AUDIO_API
void gst_dsd_info_set_format (GstDsdInfo * info,
GstDsdFormat format,
gint rate,
gint channels,
const GstAudioChannelPosition * positions);
GST_AUDIO_API
GstDsdInfo * gst_dsd_info_copy (const GstDsdInfo * info);
GST_AUDIO_API
void gst_dsd_info_free (GstDsdInfo * info);
GST_AUDIO_API
gboolean gst_dsd_info_from_caps (GstDsdInfo *info,
const GstCaps *caps);
GST_AUDIO_API
GstCaps * gst_dsd_info_to_caps (const GstDsdInfo *info);
GST_AUDIO_API
gboolean gst_dsd_info_is_equal (const GstDsdInfo *info,
const GstDsdInfo *other);
GST_AUDIO_API
void gst_dsd_convert (const guint8 *input_data,
guint8 *output_data,
GstDsdFormat input_format,
GstDsdFormat output_format,
GstAudioLayout input_layout,
GstAudioLayout output_layout,
const gsize *input_plane_offsets,
const gsize *output_plane_offsets,
gsize num_dsd_bytes,
gint num_channels,
gboolean reverse_byte_bits);
/**
* gst_dsd_format_is_le:
* @format: The format.
*
* Useful for determining whether a format is a little-endian.
* GST_DSD_FORMAT_U8 and GST_DSD_FORMAT_UNKNOWN
* are not considered little-endian.
*
* Returns: TRUE if the format is a little-endian one.
*/
static inline gboolean
gst_dsd_format_is_le (GstDsdFormat format)
{
switch (format) {
case GST_DSD_FORMAT_U16LE:
case GST_DSD_FORMAT_U32LE:
return TRUE;
default:
return FALSE;
}
}
G_END_DECLS