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authorAndy Wingo <wingo@pobox.com>2001-12-22 23:26:33 +0000
committerAndy Wingo <wingo@pobox.com>2001-12-22 23:26:33 +0000
commitad6ed7da2d0d15eecc924dfe408320652481e885 (patch)
tree5adb0cfc1d7b419d6b4246f616400dca7678bac0 /gst/mpegaudioparse/gstmpegaudioparse.c
parente5d9d6e2a512540848f5d38e01b9678a1ef5c761 (diff)
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Initial revision
Original commit message from CVS: Initial revision
Diffstat (limited to 'gst/mpegaudioparse/gstmpegaudioparse.c')
-rw-r--r--gst/mpegaudioparse/gstmpegaudioparse.c506
1 files changed, 506 insertions, 0 deletions
diff --git a/gst/mpegaudioparse/gstmpegaudioparse.c b/gst/mpegaudioparse/gstmpegaudioparse.c
new file mode 100644
index 00000000..b1431c73
--- /dev/null
+++ b/gst/mpegaudioparse/gstmpegaudioparse.c
@@ -0,0 +1,506 @@
+/* Gnome-Streamer
+ * 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 GST_DEBUG_ENABLED
+#include <gstmpegaudioparse.h>
+
+
+/* elementfactory information */
+static GstElementDetails mp3parse_details = {
+ "MP3 Parser",
+ "Filter/Parser/Audio",
+ "Parses and frames MP3 audio streams, provides seek",
+ VERSION,
+ "Erik Walthinsen <omega@cse.ogi.edu>",
+ "(C) 1999",
+};
+
+static GstPadTemplate*
+mp3_src_factory (void)
+{
+ return
+ gst_padtemplate_new (
+ "src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ gst_caps_new (
+ "mp3parse_src",
+ "audio/mp3",
+ gst_props_new (
+ "layer", GST_PROPS_INT_RANGE (1, 3),
+ "bitrate", GST_PROPS_INT_RANGE (8, 320),
+ "framed", GST_PROPS_BOOLEAN (TRUE),
+ NULL)),
+ NULL);
+}
+
+static GstPadTemplate*
+mp3_sink_factory (void)
+{
+ return
+ gst_padtemplate_new (
+ "sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ gst_caps_new (
+ "mp3parse_sink",
+ "audio/mp3",
+ NULL),
+ NULL);
+};
+
+/* GstMPEGAudioParse signals and args */
+enum {
+ /* FILL ME */
+ LAST_SIGNAL
+};
+
+enum {
+ ARG_0,
+ ARG_SKIP,
+ ARG_BIT_RATE,
+ /* FILL ME */
+};
+
+static GstPadTemplate *sink_temp, *src_temp;
+
+static void gst_mp3parse_class_init (GstMPEGAudioParseClass *klass);
+static void gst_mp3parse_init (GstMPEGAudioParse *mp3parse);
+
+static void gst_mp3parse_loop (GstElement *element);
+static void gst_mp3parse_chain (GstPad *pad,GstBuffer *buf);
+static long bpf_from_header (GstMPEGAudioParse *parse, unsigned long header);
+static int head_check (unsigned long head);
+
+static void gst_mp3parse_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
+static void gst_mp3parse_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
+
+static GstElementClass *parent_class = NULL;
+//static guint gst_mp3parse_signals[LAST_SIGNAL] = { 0 };
+
+GType
+mp3parse_get_type(void) {
+ static GType mp3parse_type = 0;
+
+ if (!mp3parse_type) {
+ static const GTypeInfo mp3parse_info = {
+ sizeof(GstMPEGAudioParseClass), NULL,
+ NULL,
+ (GClassInitFunc)gst_mp3parse_class_init,
+ NULL,
+ NULL,
+ sizeof(GstMPEGAudioParse),
+ 0,
+ (GInstanceInitFunc)gst_mp3parse_init,
+ };
+ mp3parse_type = g_type_register_static(GST_TYPE_ELEMENT, "GstMPEGAudioParse", &mp3parse_info, 0);
+ }
+ return mp3parse_type;
+}
+
+static void
+gst_mp3parse_class_init (GstMPEGAudioParseClass *klass)
+{
+ GObjectClass *gobject_class;
+ GstElementClass *gstelement_class;
+
+ gobject_class = (GObjectClass*)klass;
+ gstelement_class = (GstElementClass*)klass;
+
+ 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
+ g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_BIT_RATE,
+ g_param_spec_int("bit_rate","bit_rate","bit_rate",
+ G_MININT,G_MAXINT,0,G_PARAM_READABLE)); // CHECKME
+
+ parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
+
+ gobject_class->set_property = gst_mp3parse_set_property;
+ gobject_class->get_property = gst_mp3parse_get_property;
+}
+
+static void
+gst_mp3parse_init (GstMPEGAudioParse *mp3parse)
+{
+ mp3parse->sinkpad = gst_pad_new_from_template(sink_temp, "sink");
+ gst_pad_set_caps(mp3parse->sinkpad, gst_pad_get_padtemplate_caps (mp3parse->sinkpad));
+ gst_element_add_pad(GST_ELEMENT(mp3parse),mp3parse->sinkpad);
+// gst_pad_set_type_id(mp3parse->sinkpad, mp3type);
+
+#if 1 // set this to one to use the old chaining code
+ gst_pad_set_chain_function(mp3parse->sinkpad,gst_mp3parse_chain);
+#else // else you get the new loop-based code, which isn't complete yet
+ gst_element_set_loop_function (GST_ELEMENT(mp3parse),gst_mp3parse_loop);
+#endif
+
+ mp3parse->srcpad = gst_pad_new_from_template(src_temp, "src");
+ gst_element_add_pad(GST_ELEMENT(mp3parse),mp3parse->srcpad);
+ //gst_pad_set_type_id(mp3parse->srcpad, mp3frametype);
+
+ mp3parse->partialbuf = NULL;
+ mp3parse->skip = 0;
+ mp3parse->in_flush = FALSE;
+}
+
+static guint32
+gst_mp3parse_next_header (guchar *buf,guint32 len,guint32 start)
+{
+ guint32 offset = start;
+ int f = 0;
+
+ while (offset < (len - 4)) {
+ fprintf(stderr,"%02x ",buf[offset]);
+ if (buf[offset] == 0xff)
+ f = 1;
+ else if (f && ((buf[offset] >> 4) == 0x0f))
+ return offset - 1;
+ else
+ f = 0;
+ offset++;
+ }
+ return -1;
+}
+
+static void
+gst_mp3parse_loop (GstElement *element)
+{
+ GstMPEGAudioParse *parse = GST_MP3PARSE(element);
+ GstBuffer *inbuf, *outbuf;
+ guint32 size, offset;
+ guchar *data;
+ guint32 start;
+ guint32 header;
+ gint bpf;
+
+ while (1) {
+ // get a new buffer
+ inbuf = gst_pad_pull (parse->sinkpad);
+ size = GST_BUFFER_SIZE (inbuf);
+ data = GST_BUFFER_DATA (inbuf);
+ offset = 0;
+fprintf(stderr, "have buffer of %d bytes\n",size);
+
+ // loop through it and find all the frames
+ while (offset < (size - 4)) {
+ start = gst_mp3parse_next_header (data,size,offset);
+fprintf(stderr, "skipped %d bytes searching for the next header\n",start-offset);
+ header = GULONG_FROM_BE(*((guint32 *)(data+start)));
+fprintf(stderr, "header is 0x%08x\n",header);
+
+ // figure out how big the frame is supposed to be
+ bpf = bpf_from_header (parse, header);
+
+ // see if there are enough bytes in this buffer for the whole frame
+ if ((start + bpf) <= size) {
+ outbuf = gst_buffer_create_sub (inbuf,start,bpf);
+fprintf(stderr, "sending buffer of %d bytes\n",bpf);
+ gst_pad_push (parse->srcpad, outbuf);
+ offset = start + bpf;
+
+ // if not, we have to deal with it somehow
+ } else {
+fprintf(stderr,"don't have enough data for this frame\n");
+
+ break;
+ }
+ }
+ }
+}
+
+static void
+gst_mp3parse_chain (GstPad *pad, GstBuffer *buf)
+{
+ GstMPEGAudioParse *mp3parse;
+ guchar *data;
+ glong size,offset = 0;
+ unsigned long header;
+ int bpf;
+ GstBuffer *outbuf;
+ guint64 last_ts;
+
+ 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));
+
+ mp3parse = GST_MP3PARSE (gst_pad_get_parent (pad));
+
+ GST_DEBUG (0,"mp3parse: received buffer of %d bytes\n",GST_BUFFER_SIZE(buf));
+
+ last_ts = GST_BUFFER_TIMESTAMP(buf);
+
+ if (GST_BUFFER_FLAG_IS_SET(buf, GST_BUFFER_FLUSH)) {
+ if (mp3parse->partialbuf) {
+ gst_buffer_unref(mp3parse->partialbuf);
+ mp3parse->partialbuf = NULL;
+ }
+ mp3parse->in_flush = TRUE;
+ }
+
+ // if we have something left from the previous frame
+ if (mp3parse->partialbuf) {
+
+ mp3parse->partialbuf = gst_buffer_append(mp3parse->partialbuf, buf);
+ // and the one we received..
+ gst_buffer_unref(buf);
+ }
+ else {
+ mp3parse->partialbuf = buf;
+ }
+
+ size = GST_BUFFER_SIZE(mp3parse->partialbuf);
+ data = GST_BUFFER_DATA(mp3parse->partialbuf);
+
+ // while we still have bytes left -4 for the header
+ while (offset < size-4) {
+ int skipped = 0;
+
+ GST_DEBUG (0,"mp3parse: offset %ld, size %ld \n",offset, size);
+
+ // search for a possible start byte
+ for (;((data[offset] != 0xff) && (offset < size));offset++) skipped++;
+ if (skipped && !mp3parse->in_flush) {
+ GST_DEBUG (0,"mp3parse: **** now at %ld skipped %d bytes\n",offset,skipped);
+ }
+ // construct the header word
+ header = GULONG_FROM_BE(*((gulong *)(data+offset)));
+ // if it's a valid header, go ahead and send off the frame
+ if (head_check(header)) {
+ // calculate the bpf of the frame
+ bpf = bpf_from_header(mp3parse, header);
+
+ /********************************************************************************
+ * robust seek support
+ * - This performs additional frame validation if the in_flush flag is set
+ * (indicating a discontinuous stream).
+ * - The current frame header is not accepted as valid unless the NEXT frame
+ * header has the same values for most fields. This significantly increases
+ * the probability that we aren't processing random data.
+ * - It is not clear if this is sufficient for robust seeking of Layer III
+ * streams which utilize the concept of a "bit reservoir" by borrow bitrate
+ * from previous frames. In this case, seeking may be more complicated because
+ * the frames are not independently coded.
+ ********************************************************************************/
+ if ( mp3parse->in_flush ) {
+ unsigned long header2;
+
+ if ((size-offset)<(bpf+4)) { if (mp3parse->in_flush) break; } // wait until we have the the entire current frame as well as the next frame header
+
+ header2 = GULONG_FROM_BE(*((gulong *)(data+offset+bpf)));
+ GST_DEBUG(0,"mp3parse: header=%08lX, header2=%08lX, bpf=%d\n", header, header2, bpf );
+
+ #define HDRMASK ~( (0xF<<12)/*bitrate*/ | (1<<9)/*padding*/ | (3<<4)/*mode extension*/ ) // mask the bits which are allowed to differ between frames
+
+ if ( (header2&HDRMASK) != (header&HDRMASK) ) { // require 2 matching headers in a row
+ GST_DEBUG(0,"mp3parse: next header doesn't match (header=%08lX, header2=%08lX, bpf=%d)\n", header, header2, bpf );
+ offset++; // This frame is invalid. Start looking for a valid frame at the next position in the stream
+ continue;
+ }
+
+ }
+
+ // if we don't have the whole frame...
+ if ((size - offset) < bpf) {
+ GST_DEBUG (0,"mp3parse: partial buffer needed %ld < %d \n",(size-offset), bpf);
+ break;
+ } else {
+
+ outbuf = gst_buffer_create_sub(mp3parse->partialbuf,offset,bpf);
+
+ offset += bpf;
+ if (mp3parse->skip == 0) {
+ GST_DEBUG (0,"mp3parse: pushing buffer of %d bytes\n",GST_BUFFER_SIZE(outbuf));
+ if (mp3parse->in_flush) {
+ GST_BUFFER_FLAG_SET(outbuf, GST_BUFFER_FLUSH);
+ mp3parse->in_flush = FALSE;
+ }
+ else {
+ GST_BUFFER_FLAG_UNSET(outbuf, GST_BUFFER_FLUSH);
+ }
+ GST_BUFFER_TIMESTAMP(outbuf) = last_ts;
+ gst_pad_push(mp3parse->srcpad,outbuf);
+ }
+ else {
+ GST_DEBUG (0,"mp3parse: skipping buffer of %d bytes\n",GST_BUFFER_SIZE(outbuf));
+ gst_buffer_unref(outbuf);
+ mp3parse->skip--;
+ }
+ }
+ } else {
+ offset++;
+ if (!mp3parse->in_flush) GST_DEBUG (0,"mp3parse: *** 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) {
+ glong remainder = (size - offset);
+ GST_DEBUG (0,"mp3parse: partial buffer needed %ld for trailing bytes\n",remainder);
+
+ outbuf = gst_buffer_create_sub(mp3parse->partialbuf,offset,remainder);
+ gst_buffer_unref(mp3parse->partialbuf);
+ mp3parse->partialbuf = outbuf;
+ }
+ else {
+ gst_buffer_unref(mp3parse->partialbuf);
+ mp3parse->partialbuf = NULL;
+ }
+}
+
+static int mp3parse_tabsel[2][3][16] =
+{ { {0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, },
+ {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, },
+ {0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, } },
+ { {0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, },
+ {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, },
+ {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, } },
+};
+
+static long mp3parse_freqs[9] =
+{44100, 48000, 32000, 22050, 24000, 16000, 11025, 12000, 8000};
+
+
+static long
+bpf_from_header (GstMPEGAudioParse *parse, unsigned long header)
+{
+ int layer_index,layer,lsf,samplerate_index,padding;
+ long bpf;
+
+ //mpegver = (header >> 19) & 0x3; // don't need this for bpf
+ layer_index = (header >> 17) & 0x3;
+ layer = 4 - layer_index;
+ lsf = (header & (1 << 20)) ? ((header & (1 << 19)) ? 0 : 1) : 1;
+ parse->bit_rate = mp3parse_tabsel[lsf][layer - 1][((header >> 12) & 0xf)];
+ samplerate_index = (header >> 10) & 0x3;
+ padding = (header >> 9) & 0x1;
+
+ if (layer == 1) {
+ bpf = parse->bit_rate * 12000;
+ bpf /= mp3parse_freqs[samplerate_index];
+ bpf = ((bpf + padding) << 2);
+ } else {
+ bpf = parse->bit_rate * 144000;
+ bpf /= mp3parse_freqs[samplerate_index];
+ bpf += padding;
+ }
+
+ //g_print("%08x: layer %d lsf %d bitrate %d samplerate_index %d padding %d - bpf %d\n",
+//header,layer,lsf,bitrate,samplerate_index,padding,bpf);
+
+ return bpf;
+}
+
+static gboolean
+head_check (unsigned long head)
+{
+ GST_DEBUG (0,"checking mp3 header 0x%08lx\n",head);
+ /* if it's not a valid sync */
+ if ((head & 0xffe00000) != 0xffe00000) {
+ GST_DEBUG (0,"invalid sync\n");return FALSE; }
+ /* if it's an invalid MPEG version */
+ if (((head >> 19) & 3) == 0x1) {
+ GST_DEBUG (0,"invalid MPEG version\n");return FALSE; }
+ /* if it's an invalid layer */
+ if (!((head >> 17) & 3)) {
+ GST_DEBUG (0,"invalid layer\n");return FALSE; }
+ /* if it's an invalid bitrate */
+ if (((head >> 12) & 0xf) == 0x0) {
+ GST_DEBUG (0,"invalid bitrate\n");return FALSE; }
+ if (((head >> 12) & 0xf) == 0xf) {
+ GST_DEBUG (0,"invalid bitrate\n");return FALSE; }
+ /* if it's an invalid samplerate */
+ if (((head >> 10) & 0x3) == 0x3) {
+ GST_DEBUG (0,"invalid samplerate\n");return FALSE; }
+ if ((head & 0xffff0000) == 0xfffe0000) {
+ GST_DEBUG (0,"invalid sync\n");return FALSE; }
+ if (head & 0x00000002) {
+ GST_DEBUG (0,"invalid emphasis\n");return FALSE; }
+
+ return TRUE;
+}
+
+static void
+gst_mp3parse_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
+{
+ GstMPEGAudioParse *src;
+
+ /* it's not null if we got it, but it might not be ours */
+ g_return_if_fail(GST_IS_MP3PARSE(object));
+ src = GST_MP3PARSE(object);
+
+ switch (prop_id) {
+ case ARG_SKIP:
+ src->skip = g_value_get_int (value);
+ break;
+ default:
+ break;
+ }
+}
+
+static void
+gst_mp3parse_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
+{
+ GstMPEGAudioParse *src;
+
+ /* it's not null if we got it, but it might not be ours */
+ g_return_if_fail(GST_IS_MP3PARSE(object));
+ src = GST_MP3PARSE(object);
+
+ switch (prop_id) {
+ case ARG_SKIP:
+ g_value_set_int (value, src->skip);
+ break;
+ case ARG_BIT_RATE:
+ g_value_set_int (value, src->bit_rate * 1000);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
+static gboolean
+plugin_init (GModule *module, GstPlugin *plugin)
+{
+ GstElementFactory *factory;
+
+ /* create an elementfactory for the mp3parse element */
+ factory = gst_elementfactory_new ("mp3parse",
+ GST_TYPE_MP3PARSE,
+ &mp3parse_details);
+ g_return_val_if_fail (factory != NULL, FALSE);
+
+ sink_temp = mp3_sink_factory ();
+ gst_elementfactory_add_padtemplate (factory, sink_temp);
+
+ src_temp = mp3_src_factory ();
+ gst_elementfactory_add_padtemplate (factory, src_temp);
+
+ gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
+
+ return TRUE;
+}
+
+GstPluginDesc plugin_desc = {
+ GST_VERSION_MAJOR,
+ GST_VERSION_MINOR,
+ "mp3parse",
+ plugin_init
+};