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gstreamer/gst/ac3parse/gstac3parse.c
Leif Johnson b71ed5aa7d + checking in plugin category changes 
Original commit message from CVS:
+ checking in plugin category changes
2003-11-16 22:02:04 +00:00

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/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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.
*/
#define PCM_BUFFER_SIZE (1152*4)
/*#define DEBUG_ENABLED*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gstac3parse.h>
/* struct and table stolen from ac3dec by Aaron Holtzman */
struct frmsize_s {
guint16 bit_rate;
guint16 frm_size[3];
};
static struct frmsize_s frmsizecod_tbl[] = {
{ 32 ,{64 ,69 ,96 } },
{ 32 ,{64 ,70 ,96 } },
{ 40 ,{80 ,87 ,120 } },
{ 40 ,{80 ,88 ,120 } },
{ 48 ,{96 ,104 ,144 } },
{ 48 ,{96 ,105 ,144 } },
{ 56 ,{112 ,121 ,168 } },
{ 56 ,{112 ,122 ,168 } },
{ 64 ,{128 ,139 ,192 } },
{ 64 ,{128 ,140 ,192 } },
{ 80 ,{160 ,174 ,240 } },
{ 80 ,{160 ,175 ,240 } },
{ 96 ,{192 ,208 ,288 } },
{ 96 ,{192 ,209 ,288 } },
{ 112 ,{224 ,243 ,336 } },
{ 112 ,{224 ,244 ,336 } },
{ 128 ,{256 ,278 ,384 } },
{ 128 ,{256 ,279 ,384 } },
{ 160 ,{320 ,348 ,480 } },
{ 160 ,{320 ,349 ,480 } },
{ 192 ,{384 ,417 ,576 } },
{ 192 ,{384 ,418 ,576 } },
{ 224 ,{448 ,487 ,672 } },
{ 224 ,{448 ,488 ,672 } },
{ 256 ,{512 ,557 ,768 } },
{ 256 ,{512 ,558 ,768 } },
{ 320 ,{640 ,696 ,960 } },
{ 320 ,{640 ,697 ,960 } },
{ 384 ,{768 ,835 ,1152 } },
{ 384 ,{768 ,836 ,1152 } },
{ 448 ,{896 ,975 ,1344 } },
{ 448 ,{896 ,976 ,1344 } },
{ 512 ,{1024 ,1114 ,1536 } },
{ 512 ,{1024 ,1115 ,1536 } },
{ 576 ,{1152 ,1253 ,1728 } },
{ 576 ,{1152 ,1254 ,1728 } },
{ 640 ,{1280 ,1393 ,1920 } },
{ 640 ,{1280 ,1394 ,1920 } }};
/* elementfactory information */
static GstElementDetails ac3parse_details = GST_ELEMENT_DETAILS (
"AC3 Parser",
"Codec/Parser/Audio",
"Parses and frames AC3 audio streams, provides seek",
"Erik Walthinsen <omega@cse.ogi.edu>"
);
/* GstAc3Parse signals and args */
enum {
/* FILL ME */
LAST_SIGNAL
};
enum {
ARG_0,
ARG_SKIP,
/* FILL ME */
};
GST_PAD_TEMPLATE_FACTORY (src_factory,
"src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_CAPS_NEW ("ac3parse_src",
"audio/ac3",
"channels", GST_PROPS_INT_RANGE (1, 6),
"rate", GST_PROPS_INT_RANGE (32000, 48000)
)
);
GST_PAD_TEMPLATE_FACTORY (sink_factory,
"sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_CAPS_NEW ("ac3parse_sink",
"audio/x-ac3",
NULL
)
);
static void gst_ac3parse_class_init (gpointer g_class);
static void gst_ac3parse_init (GstAc3Parse *ac3parse);
static void gst_ac3parse_chain (GstPad *pad,
GstData *data);
static void gst_ac3parse_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec);
static void gst_ac3parse_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
static GstElementStateReturn
gst_ac3parse_change_state (GstElement *element);
static GstElementClass *parent_class = NULL;
/*static guint gst_ac3parse_signals[LAST_SIGNAL] = { 0 };*/
GType
ac3parse_get_type (void)
{
static GType ac3parse_type = 0;
if (!ac3parse_type) {
static const GTypeInfo ac3parse_info = {
sizeof(GstAc3ParseClass), NULL,
NULL,
(GClassInitFunc)gst_ac3parse_class_init,
NULL,
NULL,
sizeof(GstAc3Parse),
0,
(GInstanceInitFunc)gst_ac3parse_init,
};
ac3parse_type = g_type_register_static(GST_TYPE_ELEMENT, "GstAc3Parse", &ac3parse_info, 0);
}
return ac3parse_type;
}
static void
gst_ac3parse_class_init (gpointer g_class)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstAc3ParseClass *klass;
klass = (GstAc3ParseClass *)g_class;
gobject_class = (GObjectClass*)klass;
gstelement_class = (GstElementClass*)klass;
gst_element_class_add_pad_template (gstelement_class,
GST_PAD_TEMPLATE_GET(src_factory));
gst_element_class_add_pad_template (gstelement_class,
GST_PAD_TEMPLATE_GET(sink_factory));
gst_element_class_set_details (gstelement_class,
&ac3parse_details);
g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_SKIP,
g_param_spec_int("skip","skip","skip",
G_MININT,G_MAXINT,0,G_PARAM_READWRITE)); /* CHECKME */
parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
gobject_class->set_property = gst_ac3parse_set_property;
gobject_class->get_property = gst_ac3parse_get_property;
gstelement_class->change_state = gst_ac3parse_change_state;
}
static void
gst_ac3parse_init (GstAc3Parse *ac3parse)
{
ac3parse->sinkpad = gst_pad_new_from_template (
GST_PAD_TEMPLATE_GET(sink_factory), "sink");
gst_element_add_pad (GST_ELEMENT (ac3parse), ac3parse->sinkpad);
gst_pad_set_chain_function (ac3parse->sinkpad, gst_ac3parse_chain);
ac3parse->srcpad = gst_pad_new_from_template (
GST_PAD_TEMPLATE_GET(src_factory), "src");
gst_element_add_pad (GST_ELEMENT (ac3parse), ac3parse->srcpad);
ac3parse->partialbuf = NULL;
ac3parse->skip = 0;
ac3parse->sample_rate = ac3parse->channels = -1;
}
static void
gst_ac3parse_chain (GstPad *pad, GstData *_data)
{
GstBuffer *buf = GST_BUFFER (_data);
GstAc3Parse *ac3parse;
guchar *data;
glong size,offset = 0;
guint16 header;
guint8 channeldata, acmod, mask;
GstBuffer *outbuf = NULL;
gint bpf;
guint sample_rate = -1, channels = -1;
g_return_if_fail(pad != NULL);
g_return_if_fail(GST_IS_PAD(pad));
g_return_if_fail(buf != NULL);
/* g_return_if_fail(GST_IS_BUFFER(buf)); */
ac3parse = GST_AC3PARSE(GST_OBJECT_PARENT (pad));
GST_DEBUG ("ac3parse: received buffer of %d bytes", GST_BUFFER_SIZE (buf));
/* deal with partial frame from previous buffer */
if (ac3parse->partialbuf) {
ac3parse->partialbuf = gst_buffer_merge(ac3parse->partialbuf, buf);;
/* and the one we received.. */
gst_buffer_unref(buf);
}
else {
ac3parse->partialbuf = buf;
}
data = GST_BUFFER_DATA(ac3parse->partialbuf);
size = GST_BUFFER_SIZE(ac3parse->partialbuf);
/* we're searching for at least 7 bytes. first the
* syncinfo, where 2 bytes are for the syncword
* (header ID, 0x0b77), 2 bytes crc1 (checksum) and 1 byte
* fscod+fmrsizecod (framerate/bitrate) and then the
* bitstreaminfo bsid (version), bsmod (data type) and
* acmod (channel info, 3 bits). Then some "maybe"
* bits, and then the LFE indicator (subwoofer bit) */
while (offset < size-6) {
int skipped = 0;
GST_DEBUG ("ac3parse: offset %ld, size %ld ",offset, size);
/* search for a possible start byte */
for (;((data[offset] != 0x0b) && (offset < size-6));offset++) skipped++ ;
if (skipped) {
fprintf(stderr, "ac3parse: **** now at %ld skipped %d bytes (FIXME?)\n",offset,skipped);
}
/* construct the header word */
header = GUINT16_TO_BE(*((guint16 *)(data+offset)));
/* g_print("AC3PARSE: sync word is 0x%02X\n",header); */
/* if it's a valid header, go ahead and send off the frame */
if (header == 0x0b77) {
gint rate, fsize;
/* g_print("AC3PARSE: found sync at %d\n",offset); */
/* get the bits we're interested in */
rate = (data[offset+4] >> 6) & 0x3;
switch (rate) {
case 0x0: /* 00b */
sample_rate = 48000;
break;
case 0x1: /* 01b */
sample_rate = 44100;
break;
case 0x2: /* 10b */
sample_rate = 32000;
break;
case 0x3: /* 11b */
default:
/* reserved. if this happens, we're screwed */
g_assert (0);
break;
}
fsize = data[offset+4] & 0x3f;
/* calculate the bpf of the frame */
bpf = frmsizecod_tbl[fsize].frm_size[rate] * 2;
/* calculate number of channels */
channeldata = data[offset+6]; /* skip bsid/bsmod */
acmod = (channeldata >> 5) & 0x7;
switch (acmod) {
case 0x1: /* 001b = 1 channel */
channels = 1;
break;
case 0x0: /* 000b = 2 independent channels*/
case 0x2: /* 010b = 2x front (stereo) */
channels = 2;
break;
case 0x3: /* 011b = 3 front */
case 0x4: /* 100b = 2 front, 1 rear */
channels = 3;
break;
case 0x5: /* 101b = 3 front, 1 rear */
case 0x6: /* 110b = 2 front, 2 rear */
channels = 4;
break;
case 0x7: /* 111b = 3 front, 2 rear */
channels = 5;
break;
default:
/* whaaaaaaaaaaaaaa!!!!!!!!!!! */
g_assert (0);
}
/* fetch LFE bit (subwoofer) */
mask = 0x10;
if (acmod & 0x1 && acmod != 0x1) /* 3 front speakers? */
mask >>= 2;
if (acmod & 0x4) /* surround channel? */
mask >>= 2;
if (acmod == 0x2) /* 2/0 mode? */
mask >>= 2;
if (channeldata & mask) /* LFE: do we have a subwoofer channel? */
channels++;
/* if we don't have the whole frame... */
if ((size - offset) < bpf) {
GST_DEBUG ("ac3parse: partial buffer needed %ld < %d ",size-offset, bpf);
break;
} else {
gboolean need_capsnego = FALSE;
outbuf = gst_buffer_create_sub (ac3parse->partialbuf,offset,bpf);
/* make sure our properties still match */
if (channels > 0 && ac3parse->channels != channels) {
ac3parse->channels = channels;
need_capsnego = TRUE;
}
if (sample_rate > 0 && ac3parse->sample_rate != sample_rate) {
ac3parse->sample_rate = sample_rate;
need_capsnego = TRUE;
}
if (need_capsnego) {
GstCaps *newcaps;
newcaps = GST_CAPS_NEW ("ac3parse_src",
"audio/x-ac3",
"channels", GST_PROPS_INT (channels),
"rate", GST_PROPS_INT (sample_rate));
if (gst_pad_try_set_caps (ac3parse->srcpad, newcaps) <= 0) {
gst_element_error (GST_ELEMENT (ac3parse),
"Ac3parse: failed to negotiate format with next element");
return;
}
}
offset += bpf;
if (ac3parse->skip == 0 && GST_PAD_IS_LINKED(ac3parse->srcpad)) {
GST_DEBUG ("ac3parse: pushing buffer of %d bytes",GST_BUFFER_SIZE(outbuf));
gst_pad_push(ac3parse->srcpad,GST_DATA (outbuf));
}
else {
GST_DEBUG ("ac3parse: skipping buffer of %d bytes",GST_BUFFER_SIZE(outbuf));
gst_buffer_unref(outbuf);
ac3parse->skip--;
}
}
} else {
offset++;
fprintf(stderr, "ac3parse: *** wrong header, skipping byte (FIXME?)\n");
}
}
/* if we have processed this block and there are still */
/* bytes left not in a partial block, copy them over. */
if (size-offset > 0) {
gint remainder = (size - offset);
GST_DEBUG ("ac3parse: partial buffer needed %d for trailing bytes",remainder);
outbuf = gst_buffer_create_sub(ac3parse->partialbuf,offset,remainder);
gst_buffer_unref(ac3parse->partialbuf);
ac3parse->partialbuf = outbuf;
}
}
static void
gst_ac3parse_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
GstAc3Parse *src;
/* it's not null if we got it, but it might not be ours */
g_return_if_fail(GST_IS_AC3PARSE(object));
src = GST_AC3PARSE(object);
switch (prop_id) {
case ARG_SKIP:
src->skip = g_value_get_int (value);
break;
default:
break;
}
}
static void
gst_ac3parse_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
GstAc3Parse *src;
/* it's not null if we got it, but it might not be ours */
g_return_if_fail(GST_IS_AC3PARSE(object));
src = GST_AC3PARSE(object);
switch (prop_id) {
case ARG_SKIP:
g_value_set_int (value, src->skip);
break;
default:
break;
}
}
static GstElementStateReturn
gst_ac3parse_change_state (GstElement *element)
{
GstAc3Parse *ac3parse = GST_AC3PARSE(element);
switch (GST_STATE_TRANSITION (element)) {
case GST_STATE_PAUSED_TO_READY:
/* reset stream info */
ac3parse->channels = ac3parse->sample_rate = -1;
break;
}
if (GST_ELEMENT_CLASS (parent_class)->change_state)
return GST_ELEMENT_CLASS (parent_class)->change_state (element);
return GST_STATE_SUCCESS;
}
static gboolean
plugin_init (GstPlugin *plugin)
{
if(!gst_element_register(plugin, "ac3parse", GST_RANK_SECONDARY,
GST_TYPE_AC3PARSE)){
return FALSE;
}
return TRUE;
}
GST_PLUGIN_DEFINE(
GST_VERSION_MAJOR,
GST_VERSION_MINOR,
"ac3parse",
"ac3 parsing",
plugin_init,
VERSION,
"LGPL",
GST_COPYRIGHT,
GST_PACKAGE,
GST_ORIGIN
)
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