2 * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
3 * Copyright (C) 2005 Thomas Vander Stichele <thomas at apestaart dot org>
4 * Copyright (C) 2011 Wim Taymans <wim.taymans at gmail dot com>
6 * gstaudioconvert.c: Convert audio to different audio formats automatically
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
25 * SECTION:element-audioconvert
27 * Audioconvert converts raw audio buffers between various possible formats.
28 * It supports integer to float conversion, width/depth conversion,
29 * signedness and endianness conversion and channel transformations.
32 * <title>Example launch line</title>
34 * gst-launch -v -m audiotestsrc ! audioconvert ! audio/x-raw,format=S8,channels=2 ! level ! fakesink silent=TRUE
35 * ]| This pipeline converts audio to 8-bit. The level element shows that
36 * the output levels still match the one for a sine wave.
38 * gst-launch -v -m audiotestsrc ! audioconvert ! vorbisenc ! fakesink silent=TRUE
39 * ]| The vorbis encoder takes float audio data instead of the integer data
40 * generated by audiotestsrc.
43 * Last reviewed on 2006-03-02 (0.10.4)
48 * - audioconvert converts buffers in a set of supported caps. If it supports
49 * a caps, it supports conversion from these caps to any other caps it
50 * supports. (example: if it does A=>B and A=>C, it also does B=>C)
51 * - audioconvert does not save state between buffers. Every incoming buffer is
52 * converted and the converted buffer is pushed out.
54 * audioconvert is not supposed to be a one-element-does-anything solution for
64 #include "gstaudioconvert.h"
65 #include "gstchannelmix.h"
66 #include "gstaudioquantize.h"
69 GST_DEBUG_CATEGORY (audio_convert_debug);
70 GST_DEBUG_CATEGORY_STATIC (GST_CAT_PERFORMANCE);
72 /*** DEFINITIONS **************************************************************/
75 static void gst_audio_convert_dispose (GObject * obj);
77 /* gstreamer functions */
78 static gboolean gst_audio_convert_get_unit_size (GstBaseTransform * base,
79 GstCaps * caps, gsize * size);
80 static GstCaps *gst_audio_convert_transform_caps (GstBaseTransform * base,
81 GstPadDirection direction, GstCaps * caps, GstCaps * filter);
82 static void gst_audio_convert_fixate_caps (GstBaseTransform * base,
83 GstPadDirection direction, GstCaps * caps, GstCaps * othercaps);
84 static gboolean gst_audio_convert_set_caps (GstBaseTransform * base,
85 GstCaps * incaps, GstCaps * outcaps);
86 static GstFlowReturn gst_audio_convert_transform (GstBaseTransform * base,
87 GstBuffer * inbuf, GstBuffer * outbuf);
88 static GstFlowReturn gst_audio_convert_transform_ip (GstBaseTransform * base,
90 static void gst_audio_convert_set_property (GObject * object, guint prop_id,
91 const GValue * value, GParamSpec * pspec);
92 static void gst_audio_convert_get_property (GObject * object, guint prop_id,
93 GValue * value, GParamSpec * pspec);
95 /* AudioConvert signals and args */
110 GST_DEBUG_CATEGORY_INIT (audio_convert_debug, "audioconvert", 0, "audio conversion element"); \
111 GST_DEBUG_CATEGORY_GET (GST_CAT_PERFORMANCE, "GST_PERFORMANCE");
112 #define gst_audio_convert_parent_class parent_class
113 G_DEFINE_TYPE_WITH_CODE (GstAudioConvert, gst_audio_convert,
114 GST_TYPE_BASE_TRANSFORM, DEBUG_INIT);
116 /*** GSTREAMER PROTOTYPES *****************************************************/
118 #define STATIC_CAPS \
119 GST_STATIC_CAPS (GST_AUDIO_CAPS_MAKE (GST_AUDIO_FORMATS_ALL))
121 static GstStaticPadTemplate gst_audio_convert_src_template =
122 GST_STATIC_PAD_TEMPLATE ("src",
127 static GstStaticPadTemplate gst_audio_convert_sink_template =
128 GST_STATIC_PAD_TEMPLATE ("sink",
133 #define GST_TYPE_AUDIO_CONVERT_DITHERING (gst_audio_convert_dithering_get_type ())
135 gst_audio_convert_dithering_get_type (void)
137 static GType gtype = 0;
140 static const GEnumValue values[] = {
141 {DITHER_NONE, "No dithering",
143 {DITHER_RPDF, "Rectangular dithering", "rpdf"},
144 {DITHER_TPDF, "Triangular dithering (default)", "tpdf"},
145 {DITHER_TPDF_HF, "High frequency triangular dithering", "tpdf-hf"},
149 gtype = g_enum_register_static ("GstAudioConvertDithering", values);
154 #define GST_TYPE_AUDIO_CONVERT_NOISE_SHAPING (gst_audio_convert_ns_get_type ())
156 gst_audio_convert_ns_get_type (void)
158 static GType gtype = 0;
161 static const GEnumValue values[] = {
162 {NOISE_SHAPING_NONE, "No noise shaping (default)",
164 {NOISE_SHAPING_ERROR_FEEDBACK, "Error feedback", "error-feedback"},
165 {NOISE_SHAPING_SIMPLE, "Simple 2-pole noise shaping", "simple"},
166 {NOISE_SHAPING_MEDIUM, "Medium 5-pole noise shaping", "medium"},
167 {NOISE_SHAPING_HIGH, "High 8-pole noise shaping", "high"},
171 gtype = g_enum_register_static ("GstAudioConvertNoiseShaping", values);
177 /*** TYPE FUNCTIONS ***********************************************************/
179 gst_audio_convert_class_init (GstAudioConvertClass * klass)
181 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
182 GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
183 GstBaseTransformClass *basetransform_class = GST_BASE_TRANSFORM_CLASS (klass);
185 gobject_class->dispose = gst_audio_convert_dispose;
186 gobject_class->set_property = gst_audio_convert_set_property;
187 gobject_class->get_property = gst_audio_convert_get_property;
189 g_object_class_install_property (gobject_class, ARG_DITHERING,
190 g_param_spec_enum ("dithering", "Dithering",
191 "Selects between different dithering methods.",
192 GST_TYPE_AUDIO_CONVERT_DITHERING, DITHER_TPDF,
193 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
195 g_object_class_install_property (gobject_class, ARG_NOISE_SHAPING,
196 g_param_spec_enum ("noise-shaping", "Noise shaping",
197 "Selects between different noise shaping methods.",
198 GST_TYPE_AUDIO_CONVERT_NOISE_SHAPING, NOISE_SHAPING_NONE,
199 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
201 gst_element_class_add_pad_template (element_class,
202 gst_static_pad_template_get (&gst_audio_convert_src_template));
203 gst_element_class_add_pad_template (element_class,
204 gst_static_pad_template_get (&gst_audio_convert_sink_template));
205 gst_element_class_set_details_simple (element_class,
206 "Audio converter", "Filter/Converter/Audio",
207 "Convert audio to different formats", "Benjamin Otte <otte@gnome.org>");
209 basetransform_class->get_unit_size =
210 GST_DEBUG_FUNCPTR (gst_audio_convert_get_unit_size);
211 basetransform_class->transform_caps =
212 GST_DEBUG_FUNCPTR (gst_audio_convert_transform_caps);
213 basetransform_class->fixate_caps =
214 GST_DEBUG_FUNCPTR (gst_audio_convert_fixate_caps);
215 basetransform_class->set_caps =
216 GST_DEBUG_FUNCPTR (gst_audio_convert_set_caps);
217 basetransform_class->transform_ip =
218 GST_DEBUG_FUNCPTR (gst_audio_convert_transform_ip);
219 basetransform_class->transform =
220 GST_DEBUG_FUNCPTR (gst_audio_convert_transform);
222 basetransform_class->passthrough_on_same_caps = TRUE;
226 gst_audio_convert_init (GstAudioConvert * this)
228 this->dither = DITHER_TPDF;
229 this->ns = NOISE_SHAPING_NONE;
230 memset (&this->ctx, 0, sizeof (AudioConvertCtx));
232 gst_base_transform_set_gap_aware (GST_BASE_TRANSFORM (this), TRUE);
236 gst_audio_convert_dispose (GObject * obj)
238 GstAudioConvert *this = GST_AUDIO_CONVERT (obj);
240 audio_convert_clean_context (&this->ctx);
242 G_OBJECT_CLASS (parent_class)->dispose (obj);
245 /*** GSTREAMER FUNCTIONS ******************************************************/
247 /* BaseTransform vmethods */
249 gst_audio_convert_get_unit_size (GstBaseTransform * base, GstCaps * caps,
256 if (!gst_audio_info_from_caps (&info, caps))
260 GST_INFO_OBJECT (base, "unit_size = %" G_GSIZE_FORMAT, *size);
266 GST_INFO_OBJECT (base, "failed to parse caps to get unit_size");
271 /* copies the given caps */
273 gst_audio_convert_caps_remove_format_info (GstCaps * caps)
278 guint64 channel_mask;
280 res = gst_caps_new_empty ();
282 n = gst_caps_get_size (caps);
283 for (i = 0; i < n; i++) {
284 st = gst_caps_get_structure (caps, i);
286 /* If this is already expressed by the existing caps
287 * skip this structure */
288 if (i > 0 && gst_caps_is_subset_structure (res, st))
291 st = gst_structure_copy (st);
292 gst_structure_remove_field (st, "format");
294 /* Only remove the channels and channel-mask for non-NONE layouts */
295 if (gst_structure_get (st, "channel-mask", GST_TYPE_BITMASK, &channel_mask,
297 if (channel_mask != 0)
298 gst_structure_remove_fields (st, "channel-mask", "channels", NULL);
300 gst_structure_remove_fields (st, "channel-mask", "channels", NULL);
303 gst_caps_append_structure (res, st);
309 /* The caps can be transformed into any other caps with format info removed.
310 * However, we should prefer passthrough, so if passthrough is possible,
311 * put it first in the list. */
313 gst_audio_convert_transform_caps (GstBaseTransform * btrans,
314 GstPadDirection direction, GstCaps * caps, GstCaps * filter)
319 /* Get all possible caps that we can transform to */
320 tmp = gst_audio_convert_caps_remove_format_info (caps);
323 tmp2 = gst_caps_intersect_full (filter, tmp, GST_CAPS_INTERSECT_FIRST);
324 gst_caps_unref (tmp);
330 GST_DEBUG_OBJECT (btrans, "transformed %" GST_PTR_FORMAT " into %"
331 GST_PTR_FORMAT, caps, result);
336 static const GstAudioChannelPosition default_positions[8][8] = {
339 GST_AUDIO_CHANNEL_POSITION_MONO,
343 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
344 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
346 /* 3 channels (2.1) */
348 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
349 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
350 GST_AUDIO_CHANNEL_POSITION_LFE1,
352 /* 4 channels (4.0) */
354 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
355 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
356 GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
357 GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
361 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
362 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
363 GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
364 GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
365 GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
367 /* 6 channels (5.1) */
369 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
370 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
371 GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
372 GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
373 GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
374 GST_AUDIO_CHANNEL_POSITION_LFE1,
376 /* 7 channels (6.1) */
378 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
379 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
380 GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
381 GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
382 GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
383 GST_AUDIO_CHANNEL_POSITION_LFE1,
384 GST_AUDIO_CHANNEL_POSITION_REAR_CENTER,
386 /* 8 channels (7.1) */
388 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,
389 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,
390 GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,
391 GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,
392 GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,
393 GST_AUDIO_CHANNEL_POSITION_LFE1,
394 GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,
395 GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT,
400 n_bits_set (guint64 x)
406 for (i = 0; i < 64; i++) {
416 find_suitable_mask (guint64 mask, gint n_chans)
418 guint64 intersection;
423 g_assert (n_bits_set (mask) >= n_chans);
427 intersection = intersection & ((~G_GUINT64_CONSTANT (0)) >> i);
429 } while (n_bits_set (intersection) > n_chans && i < 64);
437 gst_audio_convert_fixate_channels (GstBaseTransform * base, GstStructure * ins,
440 gint in_chans, out_chans;
441 guint64 in_mask = 0, out_mask = 0;
442 gboolean has_in_mask = FALSE, has_out_mask = FALSE;
444 if (!gst_structure_get_int (ins, "channels", &in_chans))
445 return; /* this shouldn't really happen, should it? */
447 if (!gst_structure_has_field (outs, "channels")) {
448 /* we could try to get the implied number of channels from the layout,
449 * but that seems overdoing it for a somewhat exotic corner case */
450 gst_structure_remove_field (outs, "channel-mask");
454 /* ok, let's fixate the channels if they are not fixated yet */
455 gst_structure_fixate_field_nearest_int (outs, "channels", in_chans);
457 if (!gst_structure_get_int (outs, "channels", &out_chans)) {
458 /* shouldn't really happen ... */
459 gst_structure_remove_field (outs, "channel-mask");
463 /* get the channel layout of the output if any */
464 has_out_mask = gst_structure_has_field (outs, "channel-mask");
466 gst_structure_get (outs, "channel-mask", GST_TYPE_BITMASK, &out_mask, NULL);
468 /* channels == 1 => MONO */
469 if (out_chans == 2) {
471 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT |
472 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT;
477 /* get the channel layout of the input if any */
478 has_in_mask = gst_structure_has_field (ins, "channel-mask");
480 gst_structure_get (ins, "channel-mask", GST_TYPE_BITMASK, &in_mask, NULL);
482 /* channels == 1 => MONO */
485 GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT |
486 GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT;
488 } else if (in_chans > 2)
489 g_warning ("%s: Upstream caps contain no channel mask",
490 GST_ELEMENT_NAME (base));
493 if (!has_out_mask && out_chans == 1 && (in_chans != out_chans
495 return; /* nothing to do, default layout will be assumed */
497 if (in_chans == out_chans && (has_in_mask || in_chans == 1)) {
498 /* same number of channels and no output layout: just use input layout */
500 /* in_chans == 1 handled above already */
501 gst_structure_set (outs, "channel-mask", GST_TYPE_BITMASK, in_mask, NULL);
505 /* If both masks are the same we're done, this includes the NONE layout case */
506 if (in_mask == out_mask)
509 /* if output layout is fixed already and looks sane, we're done */
510 if (n_bits_set (out_mask) == out_chans)
513 if (n_bits_set (out_mask) < in_chans) {
514 /* Not much we can do here, this shouldn't just happen */
515 g_warning ("%s: Invalid downstream channel-mask with too few bits set",
516 GST_ELEMENT_NAME (base));
518 guint64 intersection;
520 /* if the output layout is not fixed, check if the output layout contains
521 * the input layout */
522 intersection = in_mask & out_mask;
523 if (n_bits_set (intersection) >= in_chans) {
524 gst_structure_set (outs, "channel-mask", GST_TYPE_BITMASK, in_mask,
529 /* output layout is not fixed and does not contain the input layout, so
530 * just pick the first possibility */
531 intersection = find_suitable_mask (out_mask, out_chans);
533 gst_structure_set (outs, "channel-mask", GST_TYPE_BITMASK, intersection,
539 /* ... else fall back to default layout (NB: out_layout is NULL here) */
540 GST_WARNING_OBJECT (base, "unexpected output channel layout");
542 guint64 intersection;
544 /* number of input channels != number of output channels:
545 * if this value contains a list of channel layouts (or even worse: a list
546 * with another list), just pick the first value and repeat until we find a
547 * channel position array or something else that's not a list; we assume
548 * the input if half-way sane and don't try to fall back on other list items
549 * if the first one is something unexpected or non-channel-pos-array-y */
550 if (n_bits_set (out_mask) >= out_chans) {
551 intersection = find_suitable_mask (out_mask, out_chans);
552 gst_structure_set (outs, "channel-mask", GST_TYPE_BITMASK, intersection,
557 /* what now?! Just ignore what we're given and use default positions */
558 GST_WARNING_OBJECT (base, "invalid or unexpected channel-positions");
561 /* missing or invalid output layout and we can't use the input layout for
562 * one reason or another, so just pick a default layout (we could be smarter
563 * and try to add/remove channels from the input layout, or pick a default
564 * layout based on LFE-presence in input layout, but let's save that for
566 if (out_chans > 0 && out_chans <= G_N_ELEMENTS (default_positions[0])) {
569 GST_DEBUG_OBJECT (base, "using default channel layout as fallback");
572 for (i = 0; i < out_chans; i++)
573 out_mask |= default_positions[out_chans - 1][i];
575 gst_structure_set (outs, "channel-mask", GST_TYPE_BITMASK, out_mask, NULL);
577 GST_ERROR_OBJECT (base, "Have no default layout for %d channels",
582 /* try to keep as many of the structure members the same by fixating the
583 * possible ranges; this way we convert the least amount of things as possible
586 gst_audio_convert_fixate_caps (GstBaseTransform * base,
587 GstPadDirection direction, GstCaps * caps, GstCaps * othercaps)
589 GstStructure *ins, *outs;
593 g_return_if_fail (gst_caps_is_fixed (caps));
595 GST_DEBUG_OBJECT (base, "trying to fixate othercaps %" GST_PTR_FORMAT
596 " based on caps %" GST_PTR_FORMAT, othercaps, caps);
598 ins = gst_caps_get_structure (caps, 0);
599 outs = gst_caps_get_structure (othercaps, 0);
601 gst_audio_convert_fixate_channels (base, ins, outs);
603 if ((fmt = gst_structure_get_string (ins, "format"))) {
604 /* FIXME, find the best format */
605 gst_structure_fixate_field_string (outs, "format", fmt);
608 if (gst_structure_get_int (ins, "rate", &rate)) {
609 if (gst_structure_has_field (outs, "rate")) {
610 gst_structure_fixate_field_nearest_int (outs, "rate", rate);
614 gst_caps_truncate (othercaps);
615 GST_DEBUG_OBJECT (base, "fixated othercaps to %" GST_PTR_FORMAT, othercaps);
619 gst_audio_convert_set_caps (GstBaseTransform * base, GstCaps * incaps,
622 GstAudioConvert *this = GST_AUDIO_CONVERT (base);
623 GstAudioInfo in_info;
624 GstAudioInfo out_info;
626 GST_DEBUG_OBJECT (base, "incaps %" GST_PTR_FORMAT ", outcaps %"
627 GST_PTR_FORMAT, incaps, outcaps);
629 if (!gst_audio_info_from_caps (&in_info, incaps))
631 if (!gst_audio_info_from_caps (&out_info, outcaps))
634 if (!audio_convert_prepare_context (&this->ctx, &in_info, &out_info,
635 this->dither, this->ns))
643 GST_ERROR_OBJECT (base, "invalid input caps");
648 GST_ERROR_OBJECT (base, "invalid output caps");
653 GST_ERROR_OBJECT (base, "could not find converter");
659 gst_audio_convert_transform_ip (GstBaseTransform * base, GstBuffer * buf)
661 /* nothing to do here */
666 gst_audio_convert_transform (GstBaseTransform * base, GstBuffer * inbuf,
670 GstAudioConvert *this = GST_AUDIO_CONVERT (base);
671 gsize srcsize, dstsize;
672 gint insize, outsize;
676 /* get amount of samples to convert. */
677 samples = gst_buffer_get_size (inbuf) / this->ctx.in.bpf;
679 /* get in/output sizes, to see if the buffers we got are of correct
681 if (!audio_convert_get_sizes (&this->ctx, samples, &insize, &outsize))
684 if (insize == 0 || outsize == 0)
687 /* get src and dst data */
688 src = gst_buffer_map (inbuf, &srcsize, NULL, GST_MAP_READ);
689 dst = gst_buffer_map (outbuf, &dstsize, NULL, GST_MAP_WRITE);
691 /* check in and outsize */
692 if (srcsize < insize)
694 if (dstsize < outsize)
697 /* and convert the samples */
698 if (!GST_BUFFER_FLAG_IS_SET (inbuf, GST_BUFFER_FLAG_GAP)) {
699 if (!audio_convert_convert (&this->ctx, src, dst,
700 samples, gst_buffer_is_writable (inbuf)))
703 /* Create silence buffer */
704 gst_audio_format_fill_silence (this->ctx.out.finfo, dst, outsize);
709 gst_buffer_unmap (outbuf, dst, outsize);
710 gst_buffer_unmap (inbuf, src, srcsize);
717 GST_ELEMENT_ERROR (this, STREAM, FORMAT,
718 (NULL), ("cannot get input/output sizes for %d samples", samples));
719 return GST_FLOW_ERROR;
723 GST_ELEMENT_ERROR (this, STREAM, FORMAT,
725 ("input/output buffers are of wrong size in: %" G_GSIZE_FORMAT " < %d"
726 " or out: %" G_GSIZE_FORMAT " < %d",
727 srcsize, insize, dstsize, outsize));
728 ret = GST_FLOW_ERROR;
733 GST_ELEMENT_ERROR (this, STREAM, FORMAT,
734 (NULL), ("error while converting"));
735 ret = GST_FLOW_ERROR;
741 gst_audio_convert_set_property (GObject * object, guint prop_id,
742 const GValue * value, GParamSpec * pspec)
744 GstAudioConvert *this = GST_AUDIO_CONVERT (object);
748 this->dither = g_value_get_enum (value);
750 case ARG_NOISE_SHAPING:
751 this->ns = g_value_get_enum (value);
754 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
760 gst_audio_convert_get_property (GObject * object, guint prop_id,
761 GValue * value, GParamSpec * pspec)
763 GstAudioConvert *this = GST_AUDIO_CONVERT (object);
767 g_value_set_enum (value, this->dither);
769 case ARG_NOISE_SHAPING:
770 g_value_set_enum (value, this->ns);
773 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);