gstreamer/subprojects/gst-plugins-base/gst-libs/gst/audio/audio-buffer.c

190 lines
6.4 KiB
C

/* GStreamer
* Copyright (C) <2018> Collabora Ltd.
* @author George Kiagiadakis <george.kiagiadakis@collabora.com>
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "audio-buffer.h"
static void
gst_audio_buffer_unmap_internal (GstAudioBuffer * buffer, guint n_unmap)
{
guint i;
for (i = 0; i < n_unmap; i++) {
gst_buffer_unmap (buffer->buffer, &buffer->map_infos[i]);
}
if (buffer->planes != buffer->priv_planes_arr)
g_free (buffer->planes);
if (buffer->map_infos != buffer->priv_map_infos_arr)
g_free (buffer->map_infos);
}
/**
* gst_audio_buffer_unmap:
* @buffer: the #GstAudioBuffer to unmap
*
* Unmaps an audio buffer that was previously mapped with
* gst_audio_buffer_map().
*
* Since: 1.16
*/
void
gst_audio_buffer_unmap (GstAudioBuffer * buffer)
{
gst_audio_buffer_unmap_internal (buffer, buffer->n_planes);
}
/**
* gst_audio_buffer_map:
* @buffer: (out caller-allocates): pointer to a #GstAudioBuffer
* @info: the audio properties of the buffer
* @gstbuffer: (transfer none): the #GstBuffer to be mapped
* @flags: the access mode for the memory
*
* Maps an audio @gstbuffer so that it can be read or written and stores the
* result of the map operation in @buffer.
*
* This is especially useful when the @gstbuffer is in non-interleaved (planar)
* layout, in which case this function will use the information in the
* @gstbuffer's attached #GstAudioMeta in order to map each channel in a
* separate "plane" in #GstAudioBuffer. If a #GstAudioMeta is not attached
* on the @gstbuffer, then it must be in interleaved layout.
*
* If a #GstAudioMeta is attached, then the #GstAudioInfo on the meta is checked
* against @info. Normally, they should be equal, but in case they are not,
* a g_critical will be printed and the #GstAudioInfo from the meta will be
* used.
*
* In non-interleaved buffers, it is possible to have each channel on a separate
* #GstMemory. In this case, each memory will be mapped separately to avoid
* copying their contents in a larger memory area. Do note though that it is
* not supported to have a single channel spanning over two or more different
* #GstMemory objects. Although the map operation will likely succeed in this
* case, it will be highly sub-optimal and it is recommended to merge all the
* memories in the buffer before calling this function.
*
* Note: The actual #GstBuffer is not ref'ed, but it is required to stay valid
* as long as it's mapped.
*
* Returns: %TRUE if the map operation succeeded or %FALSE on failure
*
* Since: 1.16
*/
gboolean
gst_audio_buffer_map (GstAudioBuffer * buffer, const GstAudioInfo * info,
GstBuffer * gstbuffer, GstMapFlags flags)
{
GstAudioMeta *meta = NULL;
guint i = 0, idx, length;
gsize skip;
g_return_val_if_fail (buffer != NULL, FALSE);
g_return_val_if_fail (info != NULL, FALSE);
g_return_val_if_fail (GST_AUDIO_INFO_IS_VALID (info), FALSE);
g_return_val_if_fail (GST_AUDIO_INFO_FORMAT (info) !=
GST_AUDIO_FORMAT_UNKNOWN, FALSE);
g_return_val_if_fail (GST_IS_BUFFER (gstbuffer), FALSE);
meta = gst_buffer_get_audio_meta (gstbuffer);
/* be strict on the layout */
g_return_val_if_fail ((!meta && info->layout == GST_AUDIO_LAYOUT_INTERLEAVED)
|| (meta && info->layout == meta->info.layout), FALSE);
/* and not so strict on other fields */
if (G_UNLIKELY (meta && !gst_audio_info_is_equal (&meta->info, info))) {
g_critical ("the GstAudioInfo argument is not equal "
"to the GstAudioMeta's attached info");
}
if (meta) {
/* make sure that the meta doesn't imply having more samples than
* what's actually possible to store in this buffer */
g_return_val_if_fail (meta->samples <=
gst_buffer_get_size (gstbuffer) / GST_AUDIO_INFO_BPF (&meta->info),
FALSE);
buffer->n_samples = meta->samples;
} else {
buffer->n_samples =
gst_buffer_get_size (gstbuffer) / GST_AUDIO_INFO_BPF (info);
}
buffer->info = meta ? meta->info : *info;
buffer->buffer = gstbuffer;
if (GST_AUDIO_BUFFER_LAYOUT (buffer) == GST_AUDIO_LAYOUT_INTERLEAVED) {
/* interleaved */
buffer->n_planes = 1;
buffer->planes = buffer->priv_planes_arr;
buffer->map_infos = buffer->priv_map_infos_arr;
if (!gst_buffer_map (gstbuffer, &buffer->map_infos[0], flags))
return FALSE;
buffer->planes[0] = buffer->map_infos[0].data;
} else {
/* non-interleaved */
buffer->n_planes = GST_AUDIO_BUFFER_CHANNELS (buffer);
if (G_UNLIKELY (buffer->n_planes > 8)) {
buffer->planes = g_new (gpointer, buffer->n_planes);
buffer->map_infos = g_new (GstMapInfo, buffer->n_planes);
} else {
buffer->planes = buffer->priv_planes_arr;
buffer->map_infos = buffer->priv_map_infos_arr;
}
if (buffer->n_samples == 0) {
memset (buffer->map_infos, 0,
buffer->n_planes * sizeof (buffer->map_infos[0]));
memset (buffer->planes, 0, buffer->n_planes * sizeof (buffer->planes[0]));
} else {
for (i = 0; i < buffer->n_planes; i++) {
if (!gst_buffer_find_memory (gstbuffer, meta->offsets[i],
GST_AUDIO_BUFFER_PLANE_SIZE (buffer), &idx, &length, &skip))
goto no_memory;
if (!gst_buffer_map_range (gstbuffer, idx, length,
&buffer->map_infos[i], flags))
goto cannot_map;
buffer->planes[i] = buffer->map_infos[i].data + skip;
}
}
}
return TRUE;
no_memory:
{
GST_DEBUG ("plane %u, no memory at offset %" G_GSIZE_FORMAT, i,
meta->offsets[i]);
gst_audio_buffer_unmap_internal (buffer, i);
return FALSE;
}
cannot_map:
{
GST_DEBUG ("cannot map memory range %u-%u", idx, length);
gst_audio_buffer_unmap_internal (buffer, i);
return FALSE;
}
}