gstreamer/gst/audioparsers/gstamrparse.c
2011-04-29 17:55:28 +02:00

371 lines
10 KiB
C

/* GStreamer Adaptive Multi-Rate parser plugin
* Copyright (C) 2006 Edgard Lima <edgard.lima@indt.org.br>
* Copyright (C) 2008 Nokia Corporation. All rights reserved.
*
* Contact: Stefan Kost <stefan.kost@nokia.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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-amrparse
* @short_description: AMR parser
* @see_also: #GstAmrnbDec, #GstAmrnbEnc
*
* This is an AMR parser capable of handling both narrow-band and wideband
* formats.
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch filesrc location=abc.amr ! amrparse ! amrdec ! audioresample ! audioconvert ! alsasink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gstamrparse.h"
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/AMR, " "rate = (int) 8000, " "channels = (int) 1;"
"audio/AMR-WB, " "rate = (int) 16000, " "channels = (int) 1;")
);
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-amr-nb-sh; audio/x-amr-wb-sh"));
GST_DEBUG_CATEGORY_STATIC (amrparse_debug);
#define GST_CAT_DEFAULT amrparse_debug
static const gint block_size_nb[16] =
{ 12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0 };
static const gint block_size_wb[16] =
{ 17, 23, 32, 36, 40, 46, 50, 58, 60, 5, -1, -1, -1, -1, 0, 0 };
/* AMR has a "hardcoded" framerate of 50fps */
#define AMR_FRAMES_PER_SECOND 50
#define AMR_FRAME_DURATION (GST_SECOND/AMR_FRAMES_PER_SECOND)
#define AMR_MIME_HEADER_SIZE 9
gboolean gst_amr_parse_start (GstBaseParse * parse);
gboolean gst_amr_parse_stop (GstBaseParse * parse);
static gboolean gst_amr_parse_sink_setcaps (GstBaseParse * parse,
GstCaps * caps);
gboolean gst_amr_parse_check_valid_frame (GstBaseParse * parse,
GstBaseParseFrame * frame, guint * framesize, gint * skipsize);
GstFlowReturn gst_amr_parse_parse_frame (GstBaseParse * parse,
GstBaseParseFrame * frame);
G_DEFINE_TYPE (GstAmrParse, gst_amr_parse, GST_TYPE_BASE_PARSE);
/**
* gst_amr_parse_class_init:
* @klass: GstAmrParseClass.
*
*/
static void
gst_amr_parse_class_init (GstAmrParseClass * klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
GstBaseParseClass *parse_class = GST_BASE_PARSE_CLASS (klass);
GST_DEBUG_CATEGORY_INIT (amrparse_debug, "amrparse", 0,
"AMR-NB audio stream parser");
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&src_template));
gst_element_class_set_details_simple (element_class,
"AMR audio stream parser", "Codec/Parser/Audio",
"Adaptive Multi-Rate audio parser",
"Ronald Bultje <rbultje@ronald.bitfreak.net>");
parse_class->start = GST_DEBUG_FUNCPTR (gst_amr_parse_start);
parse_class->stop = GST_DEBUG_FUNCPTR (gst_amr_parse_stop);
parse_class->set_sink_caps = GST_DEBUG_FUNCPTR (gst_amr_parse_sink_setcaps);
parse_class->parse_frame = GST_DEBUG_FUNCPTR (gst_amr_parse_parse_frame);
parse_class->check_valid_frame =
GST_DEBUG_FUNCPTR (gst_amr_parse_check_valid_frame);
}
/**
* gst_amr_parse_init:
* @amrparse: #GstAmrParse
* @klass: #GstAmrParseClass.
*
*/
static void
gst_amr_parse_init (GstAmrParse * amrparse)
{
/* init rest */
gst_base_parse_set_min_frame_size (GST_BASE_PARSE (amrparse), 62);
GST_DEBUG ("initialized");
}
/**
* gst_amr_parse_set_src_caps:
* @amrparse: #GstAmrParse.
*
* Set source pad caps according to current knowledge about the
* audio stream.
*
* Returns: TRUE if caps were successfully set.
*/
static gboolean
gst_amr_parse_set_src_caps (GstAmrParse * amrparse)
{
GstCaps *src_caps = NULL;
gboolean res = FALSE;
if (amrparse->wide) {
GST_DEBUG_OBJECT (amrparse, "setting srcpad caps to AMR-WB");
src_caps = gst_caps_new_simple ("audio/AMR-WB",
"channels", G_TYPE_INT, 1, "rate", G_TYPE_INT, 16000, NULL);
} else {
GST_DEBUG_OBJECT (amrparse, "setting srcpad caps to AMR-NB");
/* Max. size of NB frame is 31 bytes, so we can set the min. frame
size to 32 (+1 for next frame header) */
gst_base_parse_set_min_frame_size (GST_BASE_PARSE (amrparse), 32);
src_caps = gst_caps_new_simple ("audio/AMR",
"channels", G_TYPE_INT, 1, "rate", G_TYPE_INT, 8000, NULL);
}
gst_pad_use_fixed_caps (GST_BASE_PARSE (amrparse)->srcpad);
res = gst_pad_set_caps (GST_BASE_PARSE (amrparse)->srcpad, src_caps);
gst_caps_unref (src_caps);
return res;
}
/**
* gst_amr_parse_sink_setcaps:
* @sinkpad: GstPad
* @caps: GstCaps
*
* Returns: TRUE on success.
*/
static gboolean
gst_amr_parse_sink_setcaps (GstBaseParse * parse, GstCaps * caps)
{
GstAmrParse *amrparse;
GstStructure *structure;
const gchar *name;
amrparse = GST_AMR_PARSE (parse);
structure = gst_caps_get_structure (caps, 0);
name = gst_structure_get_name (structure);
GST_DEBUG_OBJECT (amrparse, "setcaps: %s", name);
if (!strncmp (name, "audio/x-amr-wb-sh", 17)) {
amrparse->block_size = block_size_wb;
amrparse->wide = 1;
} else if (!strncmp (name, "audio/x-amr-nb-sh", 17)) {
amrparse->block_size = block_size_nb;
amrparse->wide = 0;
} else {
GST_WARNING ("Unknown caps");
return FALSE;
}
amrparse->need_header = FALSE;
gst_base_parse_set_frame_rate (GST_BASE_PARSE (amrparse), 50, 1, 2, 2);
gst_amr_parse_set_src_caps (amrparse);
return TRUE;
}
/**
* gst_amr_parse_parse_header:
* @amrparse: #GstAmrParse
* @data: Header data to be parsed.
* @skipsize: Output argument where the frame size will be stored.
*
* Check if the given data contains an AMR mime header.
*
* Returns: TRUE on success.
*/
static gboolean
gst_amr_parse_parse_header (GstAmrParse * amrparse,
const guint8 * data, gint * skipsize)
{
GST_DEBUG_OBJECT (amrparse, "Parsing header data");
if (!memcmp (data, "#!AMR-WB\n", 9)) {
GST_DEBUG_OBJECT (amrparse, "AMR-WB detected");
amrparse->block_size = block_size_wb;
amrparse->wide = TRUE;
*skipsize = amrparse->header = 9;
} else if (!memcmp (data, "#!AMR\n", 6)) {
GST_DEBUG_OBJECT (amrparse, "AMR-NB detected");
amrparse->block_size = block_size_nb;
amrparse->wide = FALSE;
*skipsize = amrparse->header = 6;
} else
return FALSE;
gst_amr_parse_set_src_caps (amrparse);
return TRUE;
}
/**
* gst_amr_parse_check_valid_frame:
* @parse: #GstBaseParse.
* @buffer: #GstBuffer.
* @framesize: Output variable where the found frame size is put.
* @skipsize: Output variable which tells how much data needs to be skipped
* until a frame header is found.
*
* Implementation of "check_valid_frame" vmethod in #GstBaseParse class.
*
* Returns: TRUE if the given data contains valid frame.
*/
gboolean
gst_amr_parse_check_valid_frame (GstBaseParse * parse,
GstBaseParseFrame * frame, guint * framesize, gint * skipsize)
{
GstBuffer *buffer;
guint8 *data;
gsize size;
gint fsize, mode, dsize;
GstAmrParse *amrparse;
gboolean ret = FALSE;
amrparse = GST_AMR_PARSE (parse);
buffer = frame->buffer;
data = gst_buffer_map (buffer, &size, NULL, GST_MAP_READ);
dsize = size;
GST_LOG ("buffer: %d bytes", dsize);
if (amrparse->need_header) {
if (dsize >= AMR_MIME_HEADER_SIZE &&
gst_amr_parse_parse_header (amrparse, data, skipsize)) {
amrparse->need_header = FALSE;
gst_base_parse_set_frame_rate (GST_BASE_PARSE (amrparse), 50, 1, 2, 2);
} else {
GST_WARNING ("media doesn't look like a AMR format");
}
/* We return FALSE, so this frame won't get pushed forward. Instead,
the "skip" value is set, so next time we will receive a valid frame. */
goto done;
}
/* Does this look like a possible frame header candidate? */
if ((data[0] & 0x83) == 0) {
/* Yep. Retrieve the frame size */
mode = (data[0] >> 3) & 0x0F;
fsize = amrparse->block_size[mode] + 1; /* +1 for the header byte */
/* We recognize this data as a valid frame when:
* - We are in sync. There is no need for extra checks then
* - We are in EOS. There might not be enough data to check next frame
* - Sync is lost, but the following data after this frame seem
* to contain a valid header as well (and there is enough data to
* perform this check)
*/
if (fsize &&
(!GST_BASE_PARSE_LOST_SYNC (parse) || GST_BASE_PARSE_DRAINING (parse)
|| (dsize > fsize && (data[fsize] & 0x83) == 0))) {
*framesize = fsize;
ret = TRUE;
goto done;
}
}
GST_LOG ("sync lost");
done:
gst_buffer_unmap (buffer, data, size);
return ret;
}
/**
* gst_amr_parse_parse_frame:
* @parse: #GstBaseParse.
* @buffer: #GstBuffer.
*
* Implementation of "parse" vmethod in #GstBaseParse class.
*
* Returns: #GstFlowReturn defining the parsing status.
*/
GstFlowReturn
gst_amr_parse_parse_frame (GstBaseParse * parse, GstBaseParseFrame * frame)
{
return GST_FLOW_OK;
}
/**
* gst_amr_parse_start:
* @parse: #GstBaseParse.
*
* Implementation of "start" vmethod in #GstBaseParse class.
*
* Returns: TRUE on success.
*/
gboolean
gst_amr_parse_start (GstBaseParse * parse)
{
GstAmrParse *amrparse;
amrparse = GST_AMR_PARSE (parse);
GST_DEBUG ("start");
amrparse->need_header = TRUE;
amrparse->header = 0;
return TRUE;
}
/**
* gst_amr_parse_stop:
* @parse: #GstBaseParse.
*
* Implementation of "stop" vmethod in #GstBaseParse class.
*
* Returns: TRUE on success.
*/
gboolean
gst_amr_parse_stop (GstBaseParse * parse)
{
GstAmrParse *amrparse;
amrparse = GST_AMR_PARSE (parse);
GST_DEBUG ("stop");
amrparse->need_header = TRUE;
amrparse->header = 0;
return TRUE;
}