gstreamer/ext/opus/gstopusparse.c

159 lines
4.5 KiB
C
Raw Normal View History

/* GStreamer
* Copyright (C) 2004 Wim Taymans <wim@fluendo.com>
* Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
* Copyright (C) 2008 Sebastian Dröge <sebastian.droege@collabora.co.uk>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-opusparse
* @see_also: opusenc, opusdec
*
* This element parses OPUS packets.
*
* <refsect2>
* <title>Example pipelines</title>
* |[
* gst-launch -v filesrc location=opusdata ! opusparse ! opusdec ! audioconvert ! audioresample ! alsasink
* ]| Decode and plays an unmuxed Opus file.
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <opus/opus.h>
#include "gstopusparse.h"
GST_DEBUG_CATEGORY_STATIC (opusparse_debug);
#define GST_CAT_DEFAULT opusparse_debug
#define MAX_PAYLOAD_BYTES 1500
static GstStaticPadTemplate opus_parse_src_factory =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-opus, framed = (boolean) true")
);
static GstStaticPadTemplate opus_parse_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-opus")
);
G_DEFINE_TYPE (GstOpusParse, gst_opus_parse, GST_TYPE_BASE_PARSE);
static gboolean gst_opus_parse_start (GstBaseParse * parse);
static gboolean gst_opus_parse_check_valid_frame (GstBaseParse * base,
GstBaseParseFrame * frame, guint * frame_size, gint * skip);
static void
gst_opus_parse_class_init (GstOpusParseClass * klass)
{
GstBaseParseClass *bpclass;
GstElementClass *element_class;
bpclass = (GstBaseParseClass *) klass;
element_class = (GstElementClass *) klass;
bpclass->start = GST_DEBUG_FUNCPTR (gst_opus_parse_start);
bpclass->check_valid_frame =
GST_DEBUG_FUNCPTR (gst_opus_parse_check_valid_frame);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&opus_parse_src_factory));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&opus_parse_sink_factory));
gst_element_class_set_details_simple (element_class, "Opus audio parser",
"Codec/Parser/Audio",
"parses opus audio streams",
"Vincent Penquerc'h <vincent.penquerch@collabora.co.uk>");
GST_DEBUG_CATEGORY_INIT (opusparse_debug, "opusparse", 0,
"opus parsing element");
}
static void
gst_opus_parse_init (GstOpusParse * parse)
{
}
static gboolean
gst_opus_parse_start (GstBaseParse * base)
{
GstOpusParse *parse = GST_OPUS_PARSE (base);
GstCaps *caps;
caps = gst_caps_from_string ("audio/x-opus");
gst_pad_set_caps (GST_BASE_PARSE_SRC_PAD (GST_BASE_PARSE (parse)), caps);
gst_caps_unref (caps);
return TRUE;
}
static gboolean
gst_opus_parse_check_valid_frame (GstBaseParse * base,
GstBaseParseFrame * frame, guint * frame_size, gint * skip)
{
GstOpusParse *parse;
guint8 *data;
gsize size;
guint32 packet_size;
int ret = FALSE;
int channels, bandwidth;
parse = GST_OPUS_PARSE (base);
data = GST_BUFFER_DATA (frame->buffer);
size = GST_BUFFER_SIZE (frame->buffer);
GST_DEBUG_OBJECT (parse, "Checking for frame, %u bytes in buffer", size);
if (size < 4) {
GST_DEBUG_OBJECT (parse, "Too small");
goto beach;
}
packet_size = GST_READ_UINT32_BE (data);
GST_DEBUG_OBJECT (parse, "Packet size: %u bytes", packet_size);
if (packet_size > MAX_PAYLOAD_BYTES) {
GST_DEBUG_OBJECT (parse, "Too large");
goto beach;
}
if (packet_size > size - 4) {
GST_DEBUG_OBJECT (parse, "Truncated");
goto beach;
}
channels = opus_packet_get_nb_channels (data + 8);
bandwidth = opus_packet_get_bandwidth (data + 8);
if (channels < 0 || bandwidth < 0) {
GST_DEBUG_OBJECT (parse, "It looked like a packet, but it is not");
goto beach;
}
GST_DEBUG_OBJECT (parse, "Got Opus packet, %d bytes");
*skip = 8;
*frame_size = packet_size;
ret = TRUE;
beach:
return ret;
}