/* GStreamer
* Copyright (C) 2009 Pioneers of the Inevitable <songbird@songbirdnest.com>
*
* Authors: Michael Smith <msmith@songbirdnest.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.
*/
/* Based on MS-ADPCM decoder in libsndfile,
Copyright (C) 1999-2002 Erik de Castro Lopo <erikd@zip.com.au
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/base/gstadapter.h>
#define GST_TYPE_ADPCM_DEC \
(adpcmdec_get_type ())
#define GST_ADPCM_DEC(obj) \
(G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ADPCM_DEC, ADPCMDec))
#define GST_CAT_DEFAULT adpcmdec_debug
GST_DEBUG_CATEGORY_STATIC (adpcmdec_debug);
static const GstElementDetails adpcmdec_details =
GST_ELEMENT_DETAILS ("MS-ADPCM decoder",
"Codec/Decoder/Audio",
"Decode MS AD-PCM audio",
"Pioneers of the Inevitable <songbird@songbirdnest.com");
static GstStaticPadTemplate adpcmdec_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-adpcm, "
"layout=(string)microsoft, "
"block_align = (int) [64, 8096], "
"rate = (int)[ 1, MAX ], " "channels = (int)[1,2]")
);
static GstStaticPadTemplate adpcmdec_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw-int, "
"depth = (int)16, "
"width = (int)16, "
"endianness = (int)" G_STRINGIFY (G_BYTE_ORDER) ", "
"signed = (boolean)TRUE, "
"channels = (int) [1,2], " "rate = (int)[1, MAX]")
);
typedef struct _ADPCMDecClass
{
GstElementClass parent_class;
} ADPCMDecClass;
typedef struct _ADPCMDec
{
GstElement parent;
GstPad *sinkpad;
GstPad *srcpad;
GstCaps *output_caps;
int rate;
int channels;
int blocksize;
gboolean is_setup;
GstClockTime timestamp;
guint64 out_samples;
GstAdapter *adapter;
} ADPCMDec;
GST_BOILERPLATE (ADPCMDec, adpcmdec, GstElement, GST_TYPE_ELEMENT);
static gboolean
adpcmdec_setup (ADPCMDec * dec)
{
dec->output_caps = gst_caps_new_simple ("audio/x-raw-int",
"rate", G_TYPE_INT, dec->rate,
"channels", G_TYPE_INT, dec->channels,
"width", G_TYPE_INT, 16,
"depth", G_TYPE_INT, 16,
"endianness", G_TYPE_INT, G_BYTE_ORDER,
"signed", G_TYPE_BOOLEAN, TRUE, NULL);
if (dec->output_caps) {
gst_pad_set_caps (dec->srcpad, dec->output_caps);
}
dec->is_setup = TRUE;
dec->timestamp = GST_CLOCK_TIME_NONE;
dec->adapter = gst_adapter_new ();
dec->out_samples = 0;
return gst_pad_push_event (dec->srcpad, gst_event_new_new_segment (FALSE,
1.0, GST_FORMAT_TIME, 0, -1, 0));
}
static void
adpcmdec_teardown (ADPCMDec * dec)
{
if (dec->output_caps) {
gst_caps_unref (dec->output_caps);
dec->output_caps = NULL;
}
if (dec->adapter) {
g_object_unref (dec->adapter);
dec->adapter = NULL;
}
dec->is_setup = FALSE;
}
static gboolean
adpcmdec_sink_setcaps (GstPad * pad, GstCaps * caps)
{
ADPCMDec *dec = (ADPCMDec *) gst_pad_get_parent (pad);
GstStructure *structure = gst_caps_get_structure (caps, 0);
if (!gst_structure_get_int (structure, "block_align", &dec->blocksize))
return FALSE;
if (!gst_structure_get_int (structure, "rate", &dec->rate))
return FALSE;
if (!gst_structure_get_int (structure, "channels", &dec->channels))
return FALSE;
if (dec->is_setup)
adpcmdec_teardown (dec);
gst_object_unref (dec);
return TRUE;
}
/*=====================================================================
* From libsndfile:
*
* MS ADPCM Block Layout.
* ======================
* Block is usually 256, 512 or 1024 bytes depending on sample rate.
* For a mono file, the block is laid out as follows:
* byte purpose
* 0 block predictor [0..6]
* 1,2 initial idelta (positive)
* 3,4 sample 1
* 5,6 sample 0
* 7..n packed bytecodes
*
* For a stereo file, the block is laid out as follows:
* byte purpose
* 0 block predictor [0..6] for left channel
* 1 block predictor [0..6] for right channel
* 2,3 initial idelta (positive) for left channel
* 4,5 initial idelta (positive) for right channel
* 6,7 sample 1 for left channel
* 8,9 sample 1 for right channel
* 10,11 sample 0 for left channel
* 12,13 sample 0 for right channel
* 14..n packed bytecodes
*
*=====================================================================
*/
static int AdaptationTable[] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
};
static int AdaptCoeff1[] = {
256, 512, 0, 192, 240, 460, 392
};
static int AdaptCoeff2[] = {
0, -256, 0, 64, 0, -208, -232
};
static gint16
read_sample (guint8 * data)
{
guint16 val = data[0] | (data[1] << 8);
return *((gint16 *) & val);
}
/* Decode a single block of data from 'data', storing 'n_samples' decoded 16 bit
samples in 'samples'.
All buffer lengths have been verified by the caller
*/
static gboolean
adpcmdec_decode_ms_block (ADPCMDec * dec, int n_samples, guint8 * data,
gint16 * samples)
{
gint16 pred[2];
gint16 idelta[2];
int idx; /* Current byte offset in 'data' */
int i; /* Current sample index in 'samples' */
/* Read the block header, verify for sanity */
if (dec->channels == 1) {
pred[0] = data[0];
idelta[0] = read_sample (data + 1);
samples[1] = read_sample (data + 3);
samples[0] = read_sample (data + 5);
idx = 7;
i = 2;
if (pred[0] < 0 || pred[0] > 6) {
GST_WARNING_OBJECT (dec, "Invalid block predictor");
return FALSE;
}
}
else {
pred[0] = data[0];
pred[1] = data[1];
idelta[0] = read_sample (data + 2);
idelta[1] = read_sample (data + 4);
samples[2] = read_sample (data + 6);
samples[3] = read_sample (data + 8);
samples[0] = read_sample (data + 10);
samples[1] = read_sample (data + 12);
idx = 14;
i = 4;
if (pred[0] < 0 || pred[0] > 6 || pred[1] < 0 || pred[1] > 6) {
GST_WARNING_OBJECT (dec, "Invalid block predictor");
return FALSE;
}
}
for (; i < n_samples; i++) {
int chan = i % dec->channels;
int bytecode;
int delta;
int current;
int predict;
if (i % 2 == 0) {
bytecode = (data[idx] >> 4) & 0x0F;
} else {
bytecode = data[idx] & 0x0F;
idx++;
}
delta = idelta[chan];
idelta[chan] = (AdaptationTable[bytecode] * delta) >> 8;
if (idelta[chan] < 16)
idelta[chan] = 16;
/* Bytecode is used above as an index into the table. Below, it's used
as a signed 4-bit value; convert appropriately */
if (bytecode & 0x8)
bytecode -= 0x10;
predict = ((samples[i - dec->channels] * AdaptCoeff1[pred[chan]]) +
(samples[i - 2 * dec->channels] * AdaptCoeff2[pred[chan]])
) >> 8;
current = (bytecode * delta) + predict;
/* Clamp to 16 bits, store decoded sample */
samples[i] = CLAMP (current, G_MININT16, G_MAXINT16);
}
return TRUE;
}
static GstFlowReturn
adpcmdec_chain (GstPad * pad, GstBuffer * buf)
{
ADPCMDec *dec = (ADPCMDec *) gst_pad_get_parent (pad);
GstFlowReturn ret = GST_FLOW_OK;
guint8 *data;
GstBuffer *outbuf = NULL;
GstBuffer *databuf = NULL;
int outsize;
int samples;
gboolean res;
if (!dec->is_setup)
adpcmdec_setup (dec);
if (dec->timestamp == GST_CLOCK_TIME_NONE)
dec->timestamp = GST_BUFFER_TIMESTAMP (buf);
gst_adapter_push (dec->adapter, buf);
while (gst_adapter_available (dec->adapter) >= dec->blocksize) {
databuf = gst_adapter_take_buffer (dec->adapter, dec->blocksize);
data = GST_BUFFER_DATA (databuf);
/* Each block has a 3 byte header per channel, plus 4 bytes per channel to
give two initial sample values per channel. Then the remainder gives
two samples per byte */
samples = (dec->blocksize - 7 * dec->channels) * 2 + 2 * dec->channels;
outsize = 2 * samples;
outbuf = gst_buffer_new_and_alloc (outsize);
res = adpcmdec_decode_ms_block (dec, samples, data,
(gint16 *) (GST_BUFFER_DATA (outbuf)));
/* Done with input data, free it */
gst_buffer_unref (databuf);
if (!res) {
gst_buffer_unref (outbuf);
GST_WARNING_OBJECT (dec, "Decode of block failed");
ret = GST_FLOW_ERROR;
goto done;
}
gst_buffer_set_caps (outbuf, dec->output_caps);
GST_BUFFER_TIMESTAMP (outbuf) = dec->timestamp;
dec->out_samples += samples / dec->channels;
dec->timestamp =
gst_util_uint64_scale_int (dec->out_samples, GST_SECOND, dec->rate);
GST_BUFFER_DURATION (outbuf) =
dec->timestamp - GST_BUFFER_TIMESTAMP (outbuf);
ret = gst_pad_push (dec->srcpad, outbuf);
if (ret != GST_FLOW_OK)
goto done;
}
done:
gst_object_unref (dec);
return ret;
}
static gboolean
adpcmdec_sink_event (GstPad * pad, GstEvent * event)
{
ADPCMDec *dec = (ADPCMDec *) gst_pad_get_parent (pad);
gboolean res;
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_FLUSH_STOP:
gst_adapter_clear (dec->adapter);
/* Fall through */
default:
res = gst_pad_push_event (dec->srcpad, event);
break;
}
gst_object_unref (dec);
return res;
}
static GstStateChangeReturn
adpcmdec_change_state (GstElement * element, GstStateChange transition)
{
GstStateChangeReturn ret;
ADPCMDec *dec = (ADPCMDec *) element;
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
break;
case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
break;
case GST_STATE_CHANGE_PAUSED_TO_READY:
adpcmdec_teardown (dec);
break;
case GST_STATE_CHANGE_READY_TO_NULL:
break;
default:
break;
}
return ret;
}
static void
adpcmdec_dispose (GObject * obj)
{
G_OBJECT_CLASS (parent_class)->dispose (obj);
}
static void
adpcmdec_init (ADPCMDec * dec, ADPCMDecClass * klass)
{
dec->sinkpad =
gst_pad_new_from_static_template (&adpcmdec_sink_template, "sink");
gst_pad_set_setcaps_function (dec->sinkpad,
GST_DEBUG_FUNCPTR (adpcmdec_sink_setcaps));
gst_pad_set_chain_function (dec->sinkpad, GST_DEBUG_FUNCPTR (adpcmdec_chain));
gst_pad_set_event_function (dec->sinkpad,
GST_DEBUG_FUNCPTR (adpcmdec_sink_event));
gst_element_add_pad (GST_ELEMENT (dec), dec->sinkpad);
dec->srcpad =
gst_pad_new_from_static_template (&adpcmdec_src_template, "src");
gst_element_add_pad (GST_ELEMENT (dec), dec->srcpad);
}
static void
adpcmdec_class_init (ADPCMDecClass * klass)
{
GObjectClass *gobjectclass = (GObjectClass *) klass;
GstElementClass *gstelement_class = (GstElementClass *) klass;
gobjectclass->dispose = adpcmdec_dispose;
gstelement_class->change_state = adpcmdec_change_state;
} static void
adpcmdec_base_init (gpointer klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&adpcmdec_sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&adpcmdec_src_template));
gst_element_class_set_details (element_class, &adpcmdec_details);
}
static gboolean
plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (adpcmdec_debug, "adpcmdec", 0, "ADPCM Decoders");
if (!gst_element_register (plugin, "msadpcmdec", GST_RANK_PRIMARY,
GST_TYPE_ADPCM_DEC)) {
return FALSE;
}
return TRUE;
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR, GST_VERSION_MINOR, "adpcmdec",
"ADPCM decoder", plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME,
GST_PACKAGE_ORIGIN);