/* GStreamer MPEG audio parser * Copyright (C) 2006-2007 Jan Schmidt * Copyright (C) 2010 Mark Nauwelaerts * Copyright (C) 2010 Nokia Corporation. All rights reserved. * Contact: Stefan Kost * * 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-mpegaudioparse * @short_description: MPEG audio parser * @see_also: #GstAmrParse, #GstAACParse * * Parses and frames mpeg1 audio streams. Provides seeking. * * * Example launch line * |[ * gst-launch filesrc location=test.mp3 ! mpegaudioparse ! mad ! autoaudiosink * ]| * */ /* FIXME: we should make the base class (GstBaseParse) aware of the * XING seek table somehow, so it can use it properly for things like * accurate seeks. Currently it can only do a lookup via the convert function, * but then doesn't know what the result represents exactly. One could either * add a vfunc for index lookup, or just make mpegaudioparse populate the * base class's index via the API provided. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include "gstmpegaudioparse.h" #include GST_DEBUG_CATEGORY_STATIC (mpeg_audio_parse_debug); #define GST_CAT_DEFAULT mpeg_audio_parse_debug #define MPEG_AUDIO_CHANNEL_MODE_UNKNOWN -1 #define MPEG_AUDIO_CHANNEL_MODE_STEREO 0 #define MPEG_AUDIO_CHANNEL_MODE_JOINT_STEREO 1 #define MPEG_AUDIO_CHANNEL_MODE_DUAL_CHANNEL 2 #define MPEG_AUDIO_CHANNEL_MODE_MONO 3 #define CRC_UNKNOWN -1 #define CRC_PROTECTED 0 #define CRC_NOT_PROTECTED 1 #define XING_FRAMES_FLAG 0x0001 #define XING_BYTES_FLAG 0x0002 #define XING_TOC_FLAG 0x0004 #define XING_VBR_SCALE_FLAG 0x0008 #define MIN_FRAME_SIZE 6 static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/mpeg, " "mpegversion = (int) 1, " "layer = (int) [ 1, 3 ], " "rate = (int) [ 8000, 48000 ], channels = (int) [ 1, 2 ]," "parsed=(boolean) true") ); static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/mpeg, mpegversion = (int) 1, parsed=(boolean)false") ); static void gst_mpeg_audio_parse_finalize (GObject * object); static gboolean gst_mpeg_audio_parse_start (GstBaseParse * parse); static gboolean gst_mpeg_audio_parse_stop (GstBaseParse * parse); static gboolean gst_mpeg_audio_parse_check_valid_frame (GstBaseParse * parse, GstBaseParseFrame * frame, guint * size, gint * skipsize); static GstFlowReturn gst_mpeg_audio_parse_parse_frame (GstBaseParse * parse, GstBaseParseFrame * frame); static GstFlowReturn gst_mpeg_audio_parse_pre_push_frame (GstBaseParse * parse, GstBaseParseFrame * frame); static gboolean gst_mpeg_audio_parse_convert (GstBaseParse * parse, GstFormat src_format, gint64 src_value, GstFormat dest_format, gint64 * dest_value); #define gst_mpeg_audio_parse_parent_class parent_class G_DEFINE_TYPE (GstMpegAudioParse, gst_mpeg_audio_parse, GST_TYPE_BASE_PARSE); #define GST_TYPE_MPEG_AUDIO_CHANNEL_MODE \ (gst_mpeg_audio_channel_mode_get_type()) static const GEnumValue mpeg_audio_channel_mode[] = { {MPEG_AUDIO_CHANNEL_MODE_UNKNOWN, "Unknown", "unknown"}, {MPEG_AUDIO_CHANNEL_MODE_MONO, "Mono", "mono"}, {MPEG_AUDIO_CHANNEL_MODE_DUAL_CHANNEL, "Dual Channel", "dual-channel"}, {MPEG_AUDIO_CHANNEL_MODE_JOINT_STEREO, "Joint Stereo", "joint-stereo"}, {MPEG_AUDIO_CHANNEL_MODE_STEREO, "Stereo", "stereo"}, {0, NULL, NULL}, }; static GType gst_mpeg_audio_channel_mode_get_type (void) { static GType mpeg_audio_channel_mode_type = 0; if (!mpeg_audio_channel_mode_type) { mpeg_audio_channel_mode_type = g_enum_register_static ("GstMpegAudioChannelMode", mpeg_audio_channel_mode); } return mpeg_audio_channel_mode_type; } static const gchar * gst_mpeg_audio_channel_mode_get_nick (gint mode) { guint i; for (i = 0; i < G_N_ELEMENTS (mpeg_audio_channel_mode); i++) { if (mpeg_audio_channel_mode[i].value == mode) return mpeg_audio_channel_mode[i].value_nick; } return NULL; } static void gst_mpeg_audio_parse_class_init (GstMpegAudioParseClass * klass) { GstBaseParseClass *parse_class = GST_BASE_PARSE_CLASS (klass); GstElementClass *element_class = GST_ELEMENT_CLASS (klass); GObjectClass *object_class = G_OBJECT_CLASS (klass); GST_DEBUG_CATEGORY_INIT (mpeg_audio_parse_debug, "mpegaudioparse", 0, "MPEG1 audio stream parser"); object_class->finalize = gst_mpeg_audio_parse_finalize; parse_class->start = GST_DEBUG_FUNCPTR (gst_mpeg_audio_parse_start); parse_class->stop = GST_DEBUG_FUNCPTR (gst_mpeg_audio_parse_stop); parse_class->check_valid_frame = GST_DEBUG_FUNCPTR (gst_mpeg_audio_parse_check_valid_frame); parse_class->parse_frame = GST_DEBUG_FUNCPTR (gst_mpeg_audio_parse_parse_frame); parse_class->pre_push_frame = GST_DEBUG_FUNCPTR (gst_mpeg_audio_parse_pre_push_frame); parse_class->convert = GST_DEBUG_FUNCPTR (gst_mpeg_audio_parse_convert); /* register tags */ #define GST_TAG_CRC "has-crc" #define GST_TAG_MODE "channel-mode" gst_tag_register (GST_TAG_CRC, GST_TAG_FLAG_META, G_TYPE_BOOLEAN, "has crc", "Using CRC", NULL); gst_tag_register (GST_TAG_MODE, GST_TAG_FLAG_ENCODED, G_TYPE_STRING, "channel mode", "MPEG audio channel mode", NULL); g_type_class_ref (GST_TYPE_MPEG_AUDIO_CHANNEL_MODE); 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, "MPEG1 Audio Parser", "Codec/Parser/Audio", "Parses and frames mpeg1 audio streams (levels 1-3), provides seek", "Jan Schmidt ," "Mark Nauwelaerts "); } static void gst_mpeg_audio_parse_reset (GstMpegAudioParse * mp3parse) { mp3parse->channels = -1; mp3parse->rate = -1; mp3parse->sent_codec_tag = FALSE; mp3parse->last_posted_crc = CRC_UNKNOWN; mp3parse->last_posted_channel_mode = MPEG_AUDIO_CHANNEL_MODE_UNKNOWN; mp3parse->hdr_bitrate = 0; mp3parse->xing_flags = 0; mp3parse->xing_bitrate = 0; mp3parse->xing_frames = 0; mp3parse->xing_total_time = 0; mp3parse->xing_bytes = 0; mp3parse->xing_vbr_scale = 0; memset (mp3parse->xing_seek_table, 0, 100); memset (mp3parse->xing_seek_table_inverse, 0, 256); mp3parse->vbri_bitrate = 0; mp3parse->vbri_frames = 0; mp3parse->vbri_total_time = 0; mp3parse->vbri_bytes = 0; mp3parse->vbri_seek_points = 0; g_free (mp3parse->vbri_seek_table); mp3parse->vbri_seek_table = NULL; mp3parse->encoder_delay = 0; mp3parse->encoder_padding = 0; } static void gst_mpeg_audio_parse_init (GstMpegAudioParse * mp3parse) { gst_mpeg_audio_parse_reset (mp3parse); } static void gst_mpeg_audio_parse_finalize (GObject * object) { G_OBJECT_CLASS (parent_class)->finalize (object); } static gboolean gst_mpeg_audio_parse_start (GstBaseParse * parse) { GstMpegAudioParse *mp3parse = GST_MPEG_AUDIO_PARSE (parse); gst_base_parse_set_min_frame_size (GST_BASE_PARSE (mp3parse), MIN_FRAME_SIZE); GST_DEBUG_OBJECT (parse, "starting"); gst_mpeg_audio_parse_reset (mp3parse); return TRUE; } static gboolean gst_mpeg_audio_parse_stop (GstBaseParse * parse) { GstMpegAudioParse *mp3parse = GST_MPEG_AUDIO_PARSE (parse); GST_DEBUG_OBJECT (parse, "stopping"); gst_mpeg_audio_parse_reset (mp3parse); return TRUE; } static const guint mp3types_bitrates[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 const guint mp3types_freqs[3][3] = { {44100, 48000, 32000}, {22050, 24000, 16000}, {11025, 12000, 8000} }; static inline guint mp3_type_frame_length_from_header (GstMpegAudioParse * mp3parse, guint32 header, guint * put_version, guint * put_layer, guint * put_channels, guint * put_bitrate, guint * put_samplerate, guint * put_mode, guint * put_crc) { guint length; gulong mode, samplerate, bitrate, layer, channels, padding, crc; gulong version; gint lsf, mpg25; if (header & (1 << 20)) { lsf = (header & (1 << 19)) ? 0 : 1; mpg25 = 0; } else { lsf = 1; mpg25 = 1; } version = 1 + lsf + mpg25; layer = 4 - ((header >> 17) & 0x3); crc = (header >> 16) & 0x1; bitrate = (header >> 12) & 0xF; bitrate = mp3types_bitrates[lsf][layer - 1][bitrate] * 1000; /* The caller has ensured we have a valid header, so bitrate can't be zero here. */ g_assert (bitrate != 0); samplerate = (header >> 10) & 0x3; samplerate = mp3types_freqs[lsf + mpg25][samplerate]; padding = (header >> 9) & 0x1; mode = (header >> 6) & 0x3; channels = (mode == 3) ? 1 : 2; switch (layer) { case 1: length = 4 * ((bitrate * 12) / samplerate + padding); break; case 2: length = (bitrate * 144) / samplerate + padding; break; default: case 3: length = (bitrate * 144) / (samplerate << lsf) + padding; break; } GST_DEBUG_OBJECT (mp3parse, "Calculated mp3 frame length of %u bytes", length); GST_DEBUG_OBJECT (mp3parse, "samplerate = %lu, bitrate = %lu, version = %lu, " "layer = %lu, channels = %lu, mode = %s", samplerate, bitrate, version, layer, channels, gst_mpeg_audio_channel_mode_get_nick (mode)); if (put_version) *put_version = version; if (put_layer) *put_layer = layer; if (put_channels) *put_channels = channels; if (put_bitrate) *put_bitrate = bitrate; if (put_samplerate) *put_samplerate = samplerate; if (put_mode) *put_mode = mode; if (put_crc) *put_crc = crc; return length; } /* Minimum number of consecutive, valid-looking frames to consider * for resyncing */ #define MIN_RESYNC_FRAMES 3 /* Perform extended validation to check that subsequent headers match * the first header given here in important characteristics, to avoid * false sync. We look for a minimum of MIN_RESYNC_FRAMES consecutive * frames to match their major characteristics. * * If at_eos is set to TRUE, we just check that we don't find any invalid * frames in whatever data is available, rather than requiring a full * MIN_RESYNC_FRAMES of data. * * Returns TRUE if we've seen enough data to validate or reject the frame. * If TRUE is returned, then *valid contains TRUE if it validated, or false * if we decided it was false sync. * If FALSE is returned, then *valid contains minimum needed data. */ static gboolean gst_mp3parse_validate_extended (GstMpegAudioParse * mp3parse, GstBuffer * buf, guint32 header, int bpf, gboolean at_eos, gint * valid) { guint32 next_header; guint8 *data; gsize available; gboolean res = TRUE; int frames_found = 1; int offset = bpf; data = gst_buffer_map (buf, &available, NULL, GST_MAP_READ); while (frames_found < MIN_RESYNC_FRAMES) { /* Check if we have enough data for all these frames, plus the next frame header. */ if (available < offset + 4) { if (at_eos) { /* Running out of data at EOS is fine; just accept it */ *valid = TRUE; goto cleanup; } else { *valid = offset + 4; res = FALSE; goto cleanup; } } next_header = GST_READ_UINT32_BE (data + offset); GST_DEBUG_OBJECT (mp3parse, "At %d: header=%08X, header2=%08X, bpf=%d", offset, (unsigned int) header, (unsigned int) next_header, bpf); /* mask the bits which are allowed to differ between frames */ #define HDRMASK ~((0xF << 12) /* bitrate */ | \ (0x1 << 9) /* padding */ | \ (0xf << 4) /* mode|mode extension */ | \ (0xf)) /* copyright|emphasis */ if ((next_header & HDRMASK) != (header & HDRMASK)) { /* If any of the unmasked bits don't match, then it's not valid */ GST_DEBUG_OBJECT (mp3parse, "next header doesn't match " "(header=%08X (%08X), header2=%08X (%08X), bpf=%d)", (guint) header, (guint) header & HDRMASK, (guint) next_header, (guint) next_header & HDRMASK, bpf); *valid = FALSE; goto cleanup; } else if ((((next_header >> 12) & 0xf) == 0) || (((next_header >> 12) & 0xf) == 0xf)) { /* The essential parts were the same, but the bitrate held an invalid value - also reject */ GST_DEBUG_OBJECT (mp3parse, "next header invalid (bitrate)"); *valid = FALSE; goto cleanup; } bpf = mp3_type_frame_length_from_header (mp3parse, next_header, NULL, NULL, NULL, NULL, NULL, NULL, NULL); offset += bpf; frames_found++; } *valid = TRUE; cleanup: gst_buffer_unmap (buf, data, available); return res; } static gboolean gst_mpeg_audio_parse_head_check (GstMpegAudioParse * mp3parse, unsigned long head) { GST_DEBUG_OBJECT (mp3parse, "checking mp3 header 0x%08lx", head); /* if it's not a valid sync */ if ((head & 0xffe00000) != 0xffe00000) { GST_WARNING_OBJECT (mp3parse, "invalid sync"); return FALSE; } /* if it's an invalid MPEG version */ if (((head >> 19) & 3) == 0x1) { GST_WARNING_OBJECT (mp3parse, "invalid MPEG version: 0x%lx", (head >> 19) & 3); return FALSE; } /* if it's an invalid layer */ if (!((head >> 17) & 3)) { GST_WARNING_OBJECT (mp3parse, "invalid layer: 0x%lx", (head >> 17) & 3); return FALSE; } /* if it's an invalid bitrate */ if (((head >> 12) & 0xf) == 0x0) { GST_WARNING_OBJECT (mp3parse, "invalid bitrate: 0x%lx." "Free format files are not supported yet", (head >> 12) & 0xf); return FALSE; } if (((head >> 12) & 0xf) == 0xf) { GST_WARNING_OBJECT (mp3parse, "invalid bitrate: 0x%lx", (head >> 12) & 0xf); return FALSE; } /* if it's an invalid samplerate */ if (((head >> 10) & 0x3) == 0x3) { GST_WARNING_OBJECT (mp3parse, "invalid samplerate: 0x%lx", (head >> 10) & 0x3); return FALSE; } if ((head & 0x3) == 0x2) { /* Ignore this as there are some files with emphasis 0x2 that can * be played fine. See BGO #537235 */ GST_WARNING_OBJECT (mp3parse, "invalid emphasis: 0x%lx", head & 0x3); } return TRUE; } static gboolean gst_mpeg_audio_parse_check_valid_frame (GstBaseParse * parse, GstBaseParseFrame * frame, guint * framesize, gint * skipsize) { GstMpegAudioParse *mp3parse = GST_MPEG_AUDIO_PARSE (parse); GstBuffer *buf = frame->buffer; GstByteReader reader; gint off, bpf; gboolean lost_sync, draining, valid, caps_change; guint32 header; guint bitrate, layer, rate, channels, version, mode, crc; guint8 *data; gsize bufsize; gboolean res = FALSE; data = gst_buffer_map (buf, &bufsize, NULL, GST_MAP_READ); if (G_UNLIKELY (bufsize < 6)) goto cleanup; gst_byte_reader_init (&reader, data, bufsize); off = gst_byte_reader_masked_scan_uint32 (&reader, 0xffe00000, 0xffe00000, 0, bufsize); GST_LOG_OBJECT (parse, "possible sync at buffer offset %d", off); /* didn't find anything that looks like a sync word, skip */ if (off < 0) { *skipsize = bufsize - 3; goto cleanup; } /* possible frame header, but not at offset 0? skip bytes before sync */ if (off > 0) { *skipsize = off; goto cleanup; } /* make sure the values in the frame header look sane */ header = GST_READ_UINT32_BE (data); if (!gst_mpeg_audio_parse_head_check (mp3parse, header)) { *skipsize = 1; goto cleanup; } GST_LOG_OBJECT (parse, "got frame"); bpf = mp3_type_frame_length_from_header (mp3parse, header, &version, &layer, &channels, &bitrate, &rate, &mode, &crc); g_assert (bpf != 0); if (channels != mp3parse->channels || rate != mp3parse->rate || layer != mp3parse->layer || version != mp3parse->version) caps_change = TRUE; else caps_change = FALSE; lost_sync = GST_BASE_PARSE_LOST_SYNC (parse); draining = GST_BASE_PARSE_DRAINING (parse); if (!draining && (lost_sync || caps_change)) { if (!gst_mp3parse_validate_extended (mp3parse, buf, header, bpf, draining, &valid)) { /* not enough data */ gst_base_parse_set_min_frame_size (parse, valid); *skipsize = 0; goto cleanup; } else { if (!valid) { *skipsize = off + 2; goto cleanup; } } } else if (draining && lost_sync && caps_change && mp3parse->rate > 0) { /* avoid caps jitter that we can't be sure of */ *skipsize = off + 2; goto cleanup; } /* restore default minimum */ gst_base_parse_set_min_frame_size (parse, MIN_FRAME_SIZE); *framesize = bpf; res = TRUE; cleanup: gst_buffer_unmap (buf, data, bufsize); return res; } static void gst_mpeg_audio_parse_handle_first_frame (GstMpegAudioParse * mp3parse, GstBuffer * buf) { const guint32 xing_id = 0x58696e67; /* 'Xing' in hex */ const guint32 info_id = 0x496e666f; /* 'Info' in hex - found in LAME CBR files */ const guint32 vbri_id = 0x56425249; /* 'VBRI' in hex */ const guint32 lame_id = 0x4c414d45; /* 'LAME' in hex */ gint offset_xing, offset_vbri; guint64 avail; gint64 upstream_total_bytes = 0; GstFormat fmt = GST_FORMAT_BYTES; guint32 read_id_xing = 0, read_id_vbri = 0; guint8 *data, *origdata; gsize bufsize; guint bitrate; if (mp3parse->sent_codec_tag) return; /* Check first frame for Xing info */ if (mp3parse->version == 1) { /* MPEG-1 file */ if (mp3parse->channels == 1) offset_xing = 0x11; else offset_xing = 0x20; } else { /* MPEG-2 header */ if (mp3parse->channels == 1) offset_xing = 0x09; else offset_xing = 0x11; } /* The VBRI tag is always at offset 0x20 */ offset_vbri = 0x20; /* Skip the 4 bytes of the MP3 header too */ offset_xing += 4; offset_vbri += 4; /* Check if we have enough data to read the Xing header */ origdata = data = gst_buffer_map (buf, &bufsize, NULL, GST_MAP_READ); avail = bufsize; if (avail >= offset_xing + 4) { read_id_xing = GST_READ_UINT32_BE (data + offset_xing); } if (avail >= offset_vbri + 4) { read_id_vbri = GST_READ_UINT32_BE (data + offset_vbri); } /* obtain real upstream total bytes */ fmt = GST_FORMAT_BYTES; if (!gst_pad_query_peer_duration (GST_BASE_PARSE_SINK_PAD (GST_BASE_PARSE (mp3parse)), &fmt, &upstream_total_bytes)) upstream_total_bytes = 0; if (read_id_xing == xing_id || read_id_xing == info_id) { guint32 xing_flags; guint bytes_needed = offset_xing + 8; gint64 total_bytes; GstClockTime total_time; GST_DEBUG_OBJECT (mp3parse, "Found Xing header marker 0x%x", xing_id); /* Move data after Xing header */ data += offset_xing + 4; /* Read 4 base bytes of flags, big-endian */ xing_flags = GST_READ_UINT32_BE (data); data += 4; if (xing_flags & XING_FRAMES_FLAG) bytes_needed += 4; if (xing_flags & XING_BYTES_FLAG) bytes_needed += 4; if (xing_flags & XING_TOC_FLAG) bytes_needed += 100; if (xing_flags & XING_VBR_SCALE_FLAG) bytes_needed += 4; if (avail < bytes_needed) { GST_DEBUG_OBJECT (mp3parse, "Not enough data to read Xing header (need %d)", bytes_needed); goto cleanup; } GST_DEBUG_OBJECT (mp3parse, "Reading Xing header"); mp3parse->xing_flags = xing_flags; if (xing_flags & XING_FRAMES_FLAG) { mp3parse->xing_frames = GST_READ_UINT32_BE (data); if (mp3parse->xing_frames == 0) { GST_WARNING_OBJECT (mp3parse, "Invalid number of frames in Xing header"); mp3parse->xing_flags &= ~XING_FRAMES_FLAG; } else { mp3parse->xing_total_time = gst_util_uint64_scale (GST_SECOND, (guint64) (mp3parse->xing_frames) * (mp3parse->spf), mp3parse->rate); } data += 4; } else { mp3parse->xing_frames = 0; mp3parse->xing_total_time = 0; } if (xing_flags & XING_BYTES_FLAG) { mp3parse->xing_bytes = GST_READ_UINT32_BE (data); if (mp3parse->xing_bytes == 0) { GST_WARNING_OBJECT (mp3parse, "Invalid number of bytes in Xing header"); mp3parse->xing_flags &= ~XING_BYTES_FLAG; } data += 4; } else { mp3parse->xing_bytes = 0; } /* If we know the upstream size and duration, compute the * total bitrate, rounded up to the nearest kbit/sec */ if ((total_time = mp3parse->xing_total_time) && (total_bytes = mp3parse->xing_bytes)) { mp3parse->xing_bitrate = gst_util_uint64_scale (total_bytes, 8 * GST_SECOND, total_time); mp3parse->xing_bitrate += 500; mp3parse->xing_bitrate -= mp3parse->xing_bitrate % 1000; } if (xing_flags & XING_TOC_FLAG) { int i, percent = 0; guchar *table = mp3parse->xing_seek_table; guchar old = 0, new; guint first; first = data[0]; GST_DEBUG_OBJECT (mp3parse, "Subtracting initial offset of %d bytes from Xing TOC", first); /* xing seek table: percent time -> 1/256 bytepos */ for (i = 0; i < 100; i++) { new = data[i] - first; if (old > new) { GST_WARNING_OBJECT (mp3parse, "Skipping broken Xing TOC"); mp3parse->xing_flags &= ~XING_TOC_FLAG; goto skip_toc; } mp3parse->xing_seek_table[i] = old = new; } /* build inverse table: 1/256 bytepos -> 1/100 percent time */ for (i = 0; i < 256; i++) { while (percent < 99 && table[percent + 1] <= i) percent++; if (table[percent] == i) { mp3parse->xing_seek_table_inverse[i] = percent * 100; } else if (table[percent] < i && percent < 99) { gdouble fa, fb, fx; gint a = percent, b = percent + 1; fa = table[a]; fb = table[b]; fx = (b - a) / (fb - fa) * (i - fa) + a; mp3parse->xing_seek_table_inverse[i] = (guint16) (fx * 100); } else if (percent == 99) { gdouble fa, fb, fx; gint a = percent, b = 100; fa = table[a]; fb = 256.0; fx = (b - a) / (fb - fa) * (i - fa) + a; mp3parse->xing_seek_table_inverse[i] = (guint16) (fx * 100); } } skip_toc: data += 100; } else { memset (mp3parse->xing_seek_table, 0, 100); memset (mp3parse->xing_seek_table_inverse, 0, 256); } if (xing_flags & XING_VBR_SCALE_FLAG) { mp3parse->xing_vbr_scale = GST_READ_UINT32_BE (data); data += 4; } else mp3parse->xing_vbr_scale = 0; GST_DEBUG_OBJECT (mp3parse, "Xing header reported %u frames, time %" GST_TIME_FORMAT ", %u bytes, vbr scale %u", mp3parse->xing_frames, GST_TIME_ARGS (mp3parse->xing_total_time), mp3parse->xing_bytes, mp3parse->xing_vbr_scale); /* check for truncated file */ if (upstream_total_bytes && mp3parse->xing_bytes && mp3parse->xing_bytes * 0.8 > upstream_total_bytes) { GST_WARNING_OBJECT (mp3parse, "File appears to have been truncated; " "invalidating Xing header duration and size"); mp3parse->xing_flags &= ~XING_BYTES_FLAG; mp3parse->xing_flags &= ~XING_FRAMES_FLAG; } /* Optional LAME tag? */ if (avail - bytes_needed >= 36 && GST_READ_UINT32_BE (data) == lame_id) { gchar lame_version[10] = { 0, }; guint tag_rev; guint32 encoder_delay, encoder_padding; memcpy (lame_version, data, 9); data += 9; tag_rev = data[0] >> 4; GST_DEBUG_OBJECT (mp3parse, "Found LAME tag revision %d created by '%s'", tag_rev, lame_version); /* Skip all the information we're not interested in */ data += 12; /* Encoder delay and end padding */ encoder_delay = GST_READ_UINT24_BE (data); encoder_delay >>= 12; encoder_padding = GST_READ_UINT24_BE (data); encoder_padding &= 0x000fff; mp3parse->encoder_delay = encoder_delay; mp3parse->encoder_padding = encoder_padding; GST_DEBUG_OBJECT (mp3parse, "Encoder delay %u, encoder padding %u", encoder_delay, encoder_padding); } } if (read_id_vbri == vbri_id) { gint64 total_bytes, total_frames; GstClockTime total_time; guint16 nseek_points; GST_DEBUG_OBJECT (mp3parse, "Found VBRI header marker 0x%x", vbri_id); if (avail < offset_vbri + 26) { GST_DEBUG_OBJECT (mp3parse, "Not enough data to read VBRI header (need %d)", offset_vbri + 26); goto cleanup; } GST_DEBUG_OBJECT (mp3parse, "Reading VBRI header"); /* Move data after VBRI header */ data += offset_vbri + 4; if (GST_READ_UINT16_BE (data) != 0x0001) { GST_WARNING_OBJECT (mp3parse, "Unsupported VBRI version 0x%x", GST_READ_UINT16_BE (data)); goto cleanup; } data += 2; /* Skip encoder delay */ data += 2; /* Skip quality */ data += 2; total_bytes = GST_READ_UINT32_BE (data); if (total_bytes != 0) mp3parse->vbri_bytes = total_bytes; data += 4; total_frames = GST_READ_UINT32_BE (data); if (total_frames != 0) { mp3parse->vbri_frames = total_frames; mp3parse->vbri_total_time = gst_util_uint64_scale (GST_SECOND, (guint64) (mp3parse->vbri_frames) * (mp3parse->spf), mp3parse->rate); } data += 4; /* If we know the upstream size and duration, compute the * total bitrate, rounded up to the nearest kbit/sec */ if ((total_time = mp3parse->vbri_total_time) && (total_bytes = mp3parse->vbri_bytes)) { mp3parse->vbri_bitrate = gst_util_uint64_scale (total_bytes, 8 * GST_SECOND, total_time); mp3parse->vbri_bitrate += 500; mp3parse->vbri_bitrate -= mp3parse->vbri_bitrate % 1000; } nseek_points = GST_READ_UINT16_BE (data); data += 2; if (nseek_points > 0) { guint scale, seek_bytes, seek_frames; gint i; mp3parse->vbri_seek_points = nseek_points; scale = GST_READ_UINT16_BE (data); data += 2; seek_bytes = GST_READ_UINT16_BE (data); data += 2; seek_frames = GST_READ_UINT16_BE (data); if (scale == 0 || seek_bytes == 0 || seek_bytes > 4 || seek_frames == 0) { GST_WARNING_OBJECT (mp3parse, "Unsupported VBRI seek table"); goto out_vbri; } if (avail < offset_vbri + 26 + nseek_points * seek_bytes) { GST_WARNING_OBJECT (mp3parse, "Not enough data to read VBRI seek table (need %d)", offset_vbri + 26 + nseek_points * seek_bytes); goto out_vbri; } if (seek_frames * nseek_points < total_frames - seek_frames || seek_frames * nseek_points > total_frames + seek_frames) { GST_WARNING_OBJECT (mp3parse, "VBRI seek table doesn't cover the complete file"); goto out_vbri; } if (avail < offset_vbri + 26) { GST_DEBUG_OBJECT (mp3parse, "Not enough data to read VBRI header (need %d)", offset_vbri + 26 + nseek_points * seek_bytes); goto cleanup; } data = origdata; data += offset_vbri + 26; /* VBRI seek table: frame/seek_frames -> byte */ mp3parse->vbri_seek_table = g_new (guint32, nseek_points); if (seek_bytes == 4) for (i = 0; i < nseek_points; i++) { mp3parse->vbri_seek_table[i] = GST_READ_UINT32_BE (data) * scale; data += 4; } else if (seek_bytes == 3) for (i = 0; i < nseek_points; i++) { mp3parse->vbri_seek_table[i] = GST_READ_UINT24_BE (data) * scale; data += 3; } else if (seek_bytes == 2) for (i = 0; i < nseek_points; i++) { mp3parse->vbri_seek_table[i] = GST_READ_UINT16_BE (data) * scale; data += 2; } else /* seek_bytes == 1 */ for (i = 0; i < nseek_points; i++) { mp3parse->vbri_seek_table[i] = GST_READ_UINT8 (data) * scale; data += 1; } } out_vbri: GST_DEBUG_OBJECT (mp3parse, "VBRI header reported %u frames, time %" GST_TIME_FORMAT ", bytes %u", mp3parse->vbri_frames, GST_TIME_ARGS (mp3parse->vbri_total_time), mp3parse->vbri_bytes); /* check for truncated file */ if (upstream_total_bytes && mp3parse->vbri_bytes && mp3parse->vbri_bytes * 0.8 > upstream_total_bytes) { GST_WARNING_OBJECT (mp3parse, "File appears to have been truncated; " "invalidating VBRI header duration and size"); mp3parse->vbri_valid = FALSE; } else { mp3parse->vbri_valid = TRUE; } } else { GST_DEBUG_OBJECT (mp3parse, "Xing, LAME or VBRI header not found in first frame"); } /* set duration if tables provided a valid one */ if (mp3parse->xing_flags & XING_FRAMES_FLAG) { gst_base_parse_set_duration (GST_BASE_PARSE (mp3parse), GST_FORMAT_TIME, mp3parse->xing_total_time, 0); } if (mp3parse->vbri_total_time != 0 && mp3parse->vbri_valid) { gst_base_parse_set_duration (GST_BASE_PARSE (mp3parse), GST_FORMAT_TIME, mp3parse->vbri_total_time, 0); } /* tell baseclass how nicely we can seek, and a bitrate if one found */ /* FIXME: fill index with seek table */ #if 0 seekable = GST_BASE_PARSE_SEEK_DEFAULT; if ((mp3parse->xing_flags & XING_TOC_FLAG) && mp3parse->xing_bytes && mp3parse->xing_total_time) seekable = GST_BASE_PARSE_SEEK_TABLE; if (mp3parse->vbri_seek_table && mp3parse->vbri_bytes && mp3parse->vbri_total_time) seekable = GST_BASE_PARSE_SEEK_TABLE; #endif if (mp3parse->xing_bitrate) bitrate = mp3parse->xing_bitrate; else if (mp3parse->vbri_bitrate) bitrate = mp3parse->vbri_bitrate; else bitrate = 0; gst_base_parse_set_average_bitrate (GST_BASE_PARSE (mp3parse), bitrate); cleanup: gst_buffer_unmap (buf, origdata, bufsize); } static GstFlowReturn gst_mpeg_audio_parse_parse_frame (GstBaseParse * parse, GstBaseParseFrame * frame) { GstMpegAudioParse *mp3parse = GST_MPEG_AUDIO_PARSE (parse); GstBuffer *buf = frame->buffer; guint8 *data; gsize bufsize; guint bitrate, layer, rate, channels, version, mode, crc; data = gst_buffer_map (buf, &bufsize, NULL, GST_MAP_READ); if (G_UNLIKELY (bufsize < 4)) goto short_buffer; if (!mp3_type_frame_length_from_header (mp3parse, GST_READ_UINT32_BE (data), &version, &layer, &channels, &bitrate, &rate, &mode, &crc)) goto broken_header; if (G_UNLIKELY (channels != mp3parse->channels || rate != mp3parse->rate || layer != mp3parse->layer || version != mp3parse->version)) { GstCaps *caps = gst_caps_new_simple ("audio/mpeg", "mpegversion", G_TYPE_INT, 1, "mpegaudioversion", G_TYPE_INT, version, "layer", G_TYPE_INT, layer, "rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, channels, "parsed", G_TYPE_BOOLEAN, TRUE, NULL); gst_pad_set_caps (GST_BASE_PARSE_SRC_PAD (parse), caps); gst_caps_unref (caps); mp3parse->rate = rate; mp3parse->channels = channels; mp3parse->layer = layer; mp3parse->version = version; /* see http://www.codeproject.com/audio/MPEGAudioInfo.asp */ if (mp3parse->layer == 1) mp3parse->spf = 384; else if (mp3parse->layer == 2) mp3parse->spf = 1152; else if (mp3parse->version == 1) { mp3parse->spf = 1152; } else { /* MPEG-2 or "2.5" */ mp3parse->spf = 576; } /* lead_in: * We start pushing 9 frames earlier (29 frames for MPEG2) than * segment start to be able to decode the first frame we want. * 9 (29) frames are the theoretical maximum of frames that contain * data for the current frame (bit reservoir). * * lead_out: * Some mp3 streams have an offset in the timestamps, for which we have to * push the frame *after* the end position in order for the decoder to be * able to decode everything up until the segment.stop position. */ gst_base_parse_set_frame_rate (parse, mp3parse->rate, mp3parse->spf, (version == 1) ? 10 : 30, 2); } mp3parse->hdr_bitrate = bitrate; /* For first frame; check for seek tables and output a codec tag */ gst_mpeg_audio_parse_handle_first_frame (mp3parse, buf); /* store some frame info for later processing */ mp3parse->last_crc = crc; mp3parse->last_mode = mode; gst_buffer_unmap (buf, data, bufsize); return GST_FLOW_OK; /* ERRORS */ broken_header: { /* this really shouldn't ever happen */ gst_buffer_unmap (buf, data, bufsize); GST_ELEMENT_ERROR (parse, STREAM, DECODE, (NULL), (NULL)); return GST_FLOW_ERROR; } short_buffer: { gst_buffer_unmap (buf, data, bufsize); return GST_FLOW_ERROR; } } static gboolean gst_mpeg_audio_parse_time_to_bytepos (GstMpegAudioParse * mp3parse, GstClockTime ts, gint64 * bytepos) { gint64 total_bytes; GstClockTime total_time; /* If XING seek table exists use this for time->byte conversion */ if ((mp3parse->xing_flags & XING_TOC_FLAG) && (total_bytes = mp3parse->xing_bytes) && (total_time = mp3parse->xing_total_time)) { gdouble fa, fb, fx; gdouble percent = CLAMP ((100.0 * gst_util_guint64_to_gdouble (ts)) / gst_util_guint64_to_gdouble (total_time), 0.0, 100.0); gint index = CLAMP (percent, 0, 99); fa = mp3parse->xing_seek_table[index]; if (index < 99) fb = mp3parse->xing_seek_table[index + 1]; else fb = 256.0; fx = fa + (fb - fa) * (percent - index); *bytepos = (1.0 / 256.0) * fx * total_bytes; return TRUE; } if (mp3parse->vbri_seek_table && (total_bytes = mp3parse->vbri_bytes) && (total_time = mp3parse->vbri_total_time)) { gint i, j; gdouble a, b, fa, fb; i = gst_util_uint64_scale (ts, mp3parse->vbri_seek_points - 1, total_time); i = CLAMP (i, 0, mp3parse->vbri_seek_points - 1); a = gst_guint64_to_gdouble (gst_util_uint64_scale (i, total_time, mp3parse->vbri_seek_points)); fa = 0.0; for (j = i; j >= 0; j--) fa += mp3parse->vbri_seek_table[j]; if (i + 1 < mp3parse->vbri_seek_points) { b = gst_guint64_to_gdouble (gst_util_uint64_scale (i + 1, total_time, mp3parse->vbri_seek_points)); fb = fa + mp3parse->vbri_seek_table[i + 1]; } else { b = gst_guint64_to_gdouble (total_time); fb = total_bytes; } *bytepos = fa + ((fb - fa) / (b - a)) * (gst_guint64_to_gdouble (ts) - a); return TRUE; } return FALSE; } static gboolean gst_mpeg_audio_parse_bytepos_to_time (GstMpegAudioParse * mp3parse, gint64 bytepos, GstClockTime * ts) { gint64 total_bytes; GstClockTime total_time; /* If XING seek table exists use this for byte->time conversion */ if ((mp3parse->xing_flags & XING_TOC_FLAG) && (total_bytes = mp3parse->xing_bytes) && (total_time = mp3parse->xing_total_time)) { gdouble fa, fb, fx; gdouble pos; gint index; pos = CLAMP ((bytepos * 256.0) / total_bytes, 0.0, 256.0); index = CLAMP (pos, 0, 255); fa = mp3parse->xing_seek_table_inverse[index]; if (index < 255) fb = mp3parse->xing_seek_table_inverse[index + 1]; else fb = 10000.0; fx = fa + (fb - fa) * (pos - index); *ts = (1.0 / 10000.0) * fx * gst_util_guint64_to_gdouble (total_time); return TRUE; } if (mp3parse->vbri_seek_table && (total_bytes = mp3parse->vbri_bytes) && (total_time = mp3parse->vbri_total_time)) { gint i = 0; guint64 sum = 0; gdouble a, b, fa, fb; do { sum += mp3parse->vbri_seek_table[i]; i++; } while (i + 1 < mp3parse->vbri_seek_points && sum + mp3parse->vbri_seek_table[i] < bytepos); i--; a = gst_guint64_to_gdouble (sum); fa = gst_guint64_to_gdouble (gst_util_uint64_scale (i, total_time, mp3parse->vbri_seek_points)); if (i + 1 < mp3parse->vbri_seek_points) { b = a + mp3parse->vbri_seek_table[i + 1]; fb = gst_guint64_to_gdouble (gst_util_uint64_scale (i + 1, total_time, mp3parse->vbri_seek_points)); } else { b = total_bytes; fb = gst_guint64_to_gdouble (total_time); } *ts = gst_gdouble_to_guint64 (fa + ((fb - fa) / (b - a)) * (bytepos - a)); return TRUE; } return FALSE; } static gboolean gst_mpeg_audio_parse_convert (GstBaseParse * parse, GstFormat src_format, gint64 src_value, GstFormat dest_format, gint64 * dest_value) { GstMpegAudioParse *mp3parse = GST_MPEG_AUDIO_PARSE (parse); gboolean res = FALSE; if (src_format == GST_FORMAT_TIME && dest_format == GST_FORMAT_BYTES) res = gst_mpeg_audio_parse_time_to_bytepos (mp3parse, src_value, dest_value); else if (src_format == GST_FORMAT_BYTES && dest_format == GST_FORMAT_TIME) res = gst_mpeg_audio_parse_bytepos_to_time (mp3parse, src_value, (GstClockTime *) dest_value); /* if no tables, fall back to default estimated rate based conversion */ if (!res) return gst_base_parse_convert_default (parse, src_format, src_value, dest_format, dest_value); return res; } static GstFlowReturn gst_mpeg_audio_parse_pre_push_frame (GstBaseParse * parse, GstBaseParseFrame * frame) { GstMpegAudioParse *mp3parse = GST_MPEG_AUDIO_PARSE (parse); GstTagList *taglist; /* tag sending done late enough in hook to ensure pending events * have already been sent */ if (!mp3parse->sent_codec_tag) { gchar *codec; /* codec tag */ if (mp3parse->layer == 3) { codec = g_strdup_printf ("MPEG %d Audio, Layer %d (MP3)", mp3parse->version, mp3parse->layer); } else { codec = g_strdup_printf ("MPEG %d Audio, Layer %d", mp3parse->version, mp3parse->layer); } taglist = gst_tag_list_new (); gst_tag_list_add (taglist, GST_TAG_MERGE_REPLACE, GST_TAG_AUDIO_CODEC, codec, NULL); if (mp3parse->hdr_bitrate > 0 && mp3parse->xing_bitrate == 0 && mp3parse->vbri_bitrate == 0) { /* We don't have a VBR bitrate, so post the available bitrate as * nominal and let baseparse calculate the real bitrate */ gst_tag_list_add (taglist, GST_TAG_MERGE_REPLACE, GST_TAG_NOMINAL_BITRATE, mp3parse->hdr_bitrate, NULL); } gst_element_found_tags_for_pad (GST_ELEMENT (mp3parse), GST_BASE_PARSE_SRC_PAD (mp3parse), taglist); g_free (codec); /* also signals the end of first-frame processing */ mp3parse->sent_codec_tag = TRUE; } /* we will create a taglist (if any of the parameters has changed) * to add the tags that changed */ taglist = NULL; if (mp3parse->last_posted_crc != mp3parse->last_crc) { gboolean using_crc; if (!taglist) { taglist = gst_tag_list_new (); } mp3parse->last_posted_crc = mp3parse->last_crc; if (mp3parse->last_posted_crc == CRC_PROTECTED) { using_crc = TRUE; } else { using_crc = FALSE; } gst_tag_list_add (taglist, GST_TAG_MERGE_REPLACE, GST_TAG_CRC, using_crc, NULL); } if (mp3parse->last_posted_channel_mode != mp3parse->last_mode) { if (!taglist) { taglist = gst_tag_list_new (); } mp3parse->last_posted_channel_mode = mp3parse->last_mode; gst_tag_list_add (taglist, GST_TAG_MERGE_REPLACE, GST_TAG_MODE, gst_mpeg_audio_channel_mode_get_nick (mp3parse->last_mode), NULL); } /* if the taglist exists, we need to send it */ if (taglist) { gst_element_found_tags_for_pad (GST_ELEMENT (mp3parse), GST_BASE_PARSE_SRC_PAD (mp3parse), taglist); } /* usual clipping applies */ frame->flags |= GST_BASE_PARSE_FRAME_FLAG_CLIP; return GST_FLOW_OK; }