/* GStreamer * Copyright (C) <1999> Erik Walthinsen * * 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 /* elementfactory information */ static GstElementDetails mp3parse_details = { "MPEG1 Audio Parser", "Codec/Parser", "LGPL", "Parses and frames mpeg1 audio streams (levels 1-3), provides seek", VERSION, "Erik Walthinsen ", "(C) 1999", }; static GstPadTemplate* mp3_src_factory (void) { return gst_pad_template_new ( "src", GST_PAD_SRC, GST_PAD_ALWAYS, gst_caps_new ( "mp3parse_src", "audio/x-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_pad_template_new ( "sink", GST_PAD_SINK, GST_PAD_ALWAYS, gst_caps_new ( "mp3parse_sink", "audio/x-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 gst_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_element_add_pad(GST_ELEMENT(mp3parse),mp3parse->sinkpad); gst_element_set_loop_function (GST_ELEMENT(mp3parse),gst_mp3parse_loop); #if 1 /* set this to one to use the old chaining code */ gst_pad_set_chain_function(mp3parse->sinkpad,gst_mp3parse_chain); gst_element_set_loop_function (GST_ELEMENT(mp3parse),NULL); #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 = GUINT32_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; guint32 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",GST_BUFFER_SIZE(buf)); last_ts = GST_BUFFER_TIMESTAMP(buf); /* FIXME, do 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_merge(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 ",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",offset,skipped); } /* construct the header word */ header = GUINT32_FROM_BE(*((guint32 *)(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 ) { guint32 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 = GUINT32_FROM_BE(*((guint32 *)(data+offset+bpf))); GST_DEBUG(0,"mp3parse: header=%08X, header2=%08X, bpf=%d", (unsigned int)header, (unsigned int)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=%08X, header2=%08X, bpf=%d)", (unsigned int)header, (unsigned int)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 ",(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",GST_BUFFER_SIZE(outbuf)); if (mp3parse->in_flush) { /* FIXME do some sort of flush event */ mp3parse->in_flush = FALSE; } GST_BUFFER_TIMESTAMP(outbuf) = last_ts; gst_pad_push(mp3parse->srcpad,outbuf); } else { GST_DEBUG (0,"mp3parse: skipping buffer of %d bytes",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?)"); } } /* 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",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",head); /* if it's not a valid sync */ if ((head & 0xffe00000) != 0xffe00000) { GST_DEBUG (0,"invalid sync");return FALSE; } /* if it's an invalid MPEG version */ if (((head >> 19) & 3) == 0x1) { GST_DEBUG (0,"invalid MPEG version");return FALSE; } /* if it's an invalid layer */ if (!((head >> 17) & 3)) { GST_DEBUG (0,"invalid layer");return FALSE; } /* if it's an invalid bitrate */ if (((head >> 12) & 0xf) == 0x0) { GST_DEBUG (0,"invalid bitrate");return FALSE; } if (((head >> 12) & 0xf) == 0xf) { GST_DEBUG (0,"invalid bitrate");return FALSE; } /* if it's an invalid samplerate */ if (((head >> 10) & 0x3) == 0x3) { GST_DEBUG (0,"invalid samplerate");return FALSE; } if ((head & 0xffff0000) == 0xfffe0000) { GST_DEBUG (0,"invalid sync");return FALSE; } if (head & 0x00000002) { GST_DEBUG (0,"invalid emphasis");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_element_factory_new ("mp3parse", GST_TYPE_MP3PARSE, &mp3parse_details); g_return_val_if_fail (factory != NULL, FALSE); sink_temp = mp3_sink_factory (); gst_element_factory_add_pad_template (factory, sink_temp); src_temp = mp3_src_factory (); gst_element_factory_add_pad_template (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 };