--- /dev/null
+/* GStreamer SBC audio parser
+ * Copyright (C) 2012 Collabora Ltd. <tim.muller@collabora.co.uk>
+ *
+ * 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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/**
+ * SECTION:element-sbcparse
+ * @see_also: sbcdec, sbcenc
+ *
+ * The sbcparse element will parse a bluetooth SBC audio stream into
+ * frames and timestamp them properly.
+ *
+ * Since: 1.2.0
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstsbcparse.h"
+
+#include <string.h>
+#include <gst/tag/tag.h>
+#include <gst/audio/audio.h>
+
+#include <gst/base/gstbitreader.h>
+#include <gst/base/gstbytereader.h>
+
+#define SBC_SYNCBYTE 0x9C
+
+GST_DEBUG_CATEGORY_STATIC (sbcparse_debug);
+#define GST_CAT_DEFAULT sbcparse_debug
+
+static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS ("audio/x-sbc, parsed = (boolean) true, "
+ "channels = (int) [ 1, 2 ], "
+ "rate = (int) { 16000, 32000, 44100, 48000 }")
+ );
+
+static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS ("audio/x-sbc")
+ );
+
+static gboolean gst_sbc_parse_start (GstBaseParse * parse);
+static gboolean gst_sbc_parse_stop (GstBaseParse * parse);
+static GstFlowReturn gst_sbc_parse_handle_frame (GstBaseParse * parse,
+ GstBaseParseFrame * frame, gint * skipsize);
+static GstCaps *gst_sbc_parse_get_sink_caps (GstBaseParse * parse,
+ GstCaps * filter);
+
+static guint8 gst_sbc_calculate_crc8 (const guint8 * data, gint bits_crc);
+static gsize gst_sbc_calc_framelen (guint subbands, GstSbcChannelMode ch_mode,
+ guint blocks, guint bitpool);
+static gsize gst_sbc_parse_header (const guint8 * data, guint * rate,
+ guint * n_blocks, GstSbcChannelMode * ch_mode,
+ GstSbcAllocationMethod * alloc_method, guint * n_subbands, guint * bitpool);
+
+#define parent_class gst_sbc_parse_parent_class
+G_DEFINE_TYPE (GstSbcParse, gst_sbc_parse, GST_TYPE_BASE_PARSE);
+
+static void
+gst_sbc_parse_class_init (GstSbcParseClass * klass)
+{
+ GstBaseParseClass *baseparse_class = GST_BASE_PARSE_CLASS (klass);
+ GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+ GST_DEBUG_CATEGORY_INIT (sbcparse_debug, "sbcparse", 0, "SBC audio parser");
+
+ baseparse_class->start = GST_DEBUG_FUNCPTR (gst_sbc_parse_start);
+ baseparse_class->stop = GST_DEBUG_FUNCPTR (gst_sbc_parse_stop);
+
+ baseparse_class->handle_frame =
+ GST_DEBUG_FUNCPTR (gst_sbc_parse_handle_frame);
+ baseparse_class->get_sink_caps =
+ GST_DEBUG_FUNCPTR (gst_sbc_parse_get_sink_caps);
+
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&src_factory));
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&sink_factory));
+
+ gst_element_class_set_static_metadata (element_class, "SBC audio parser",
+ "Codec/Parser/Audio", "Parses an SBC bluetooth audio stream",
+ "Tim-Philipp Müller <tim.muller@collabora.co.uk>");
+}
+
+static void
+gst_sbc_parse_reset (GstSbcParse * sbcparse)
+{
+ sbcparse->alloc_method = GST_SBC_ALLOCATION_METHOD_INVALID;
+ sbcparse->ch_mode = GST_SBC_CHANNEL_MODE_INVALID;
+ sbcparse->rate = -1;
+ sbcparse->n_blocks = -1;
+ sbcparse->n_subbands = -1;
+ sbcparse->bitpool = -1;
+}
+
+static void
+gst_sbc_parse_init (GstSbcParse * sbcparse)
+{
+ gst_sbc_parse_reset (sbcparse);
+}
+
+static gboolean
+gst_sbc_parse_start (GstBaseParse * parse)
+{
+ gst_base_parse_set_min_frame_size (parse,
+ gst_sbc_calc_framelen (4, GST_SBC_CHANNEL_MODE_MONO, 4, 2));
+
+ gst_base_parse_set_has_timing_info (parse, FALSE);
+
+ gst_base_parse_set_syncable (parse, TRUE);
+
+ return TRUE;
+}
+
+static gboolean
+gst_sbc_parse_stop (GstBaseParse * parse)
+{
+ gst_sbc_parse_reset (GST_SBC_PARSE (parse));
+ return TRUE;
+}
+
+static const gchar *
+gst_sbc_channel_mode_get_name (GstSbcChannelMode ch_mode)
+{
+ switch (ch_mode) {
+ case GST_SBC_CHANNEL_MODE_MONO:
+ return "mono";
+ case GST_SBC_CHANNEL_MODE_DUAL:
+ return "dual";
+ case GST_SBC_CHANNEL_MODE_STEREO:
+ return "stereo";
+ case GST_SBC_CHANNEL_MODE_JOINT_STEREO:
+ return "joint";
+ default:
+ break;
+ }
+ return "invalid";
+}
+
+static const gchar *
+gst_sbc_allocation_method_get_name (GstSbcAllocationMethod alloc_method)
+{
+ switch (alloc_method) {
+ case GST_SBC_ALLOCATION_METHOD_SNR:
+ return "snr";
+ case GST_SBC_ALLOCATION_METHOD_LOUDNESS:
+ return "loudness";
+ default:
+ break;
+ }
+ return "invalid";
+}
+
+static GstFlowReturn
+gst_sbc_parse_handle_frame (GstBaseParse * parse, GstBaseParseFrame * frame,
+ gint * skipsize)
+{
+ GstSbcParse *sbcparse = GST_SBC_PARSE (parse);
+ GstSbcAllocationMethod alloc_method;
+ GstSbcChannelMode ch_mode;
+ GstMapInfo map;
+ guint rate, n_blocks, n_subbands, bitpool;
+ gsize frame_len;
+
+ gst_buffer_map (frame->buffer, &map, GST_MAP_READ);
+
+ g_assert (map.size >= 6);
+
+ frame_len = gst_sbc_parse_header (map.data, &rate, &n_blocks, &ch_mode,
+ &alloc_method, &n_subbands, &bitpool);
+
+ GST_LOG_OBJECT (parse, "frame_len: %u", (guint) frame_len);
+
+ if (frame_len == 0)
+ goto resync;
+
+ if (sbcparse->alloc_method != alloc_method
+ || sbcparse->ch_mode != ch_mode
+ || sbcparse->rate != rate
+ || sbcparse->n_blocks != n_blocks
+ || sbcparse->n_subbands != n_subbands || sbcparse->bitpool != bitpool) {
+ guint avg_bitrate;
+ GstCaps *caps;
+
+ /* FIXME: do all of these need to be in the caps? */
+ caps = gst_caps_new_simple ("audio/x-sbc", "rate", G_TYPE_INT, rate,
+ "channels", G_TYPE_INT, (ch_mode == GST_SBC_CHANNEL_MODE_MONO) ? 1 : 2,
+ "channel-mode", G_TYPE_STRING, gst_sbc_channel_mode_get_name (ch_mode),
+ "blocks", G_TYPE_INT, n_blocks, "subbands", G_TYPE_INT, n_subbands,
+ "allocation-method", G_TYPE_STRING,
+ gst_sbc_allocation_method_get_name (alloc_method),
+ "bitpool", G_TYPE_INT, bitpool, "parsed", G_TYPE_BOOLEAN, TRUE, NULL);
+
+ GST_INFO_OBJECT (sbcparse, "caps changed to %" GST_PTR_FORMAT, caps);
+
+ gst_pad_push_event (GST_BASE_PARSE_SRC_PAD (sbcparse),
+ gst_event_new_caps (caps));
+
+ avg_bitrate = (8 * frame_len * rate) / (n_subbands * n_blocks);
+ gst_base_parse_set_average_bitrate (parse, avg_bitrate);
+
+ gst_base_parse_set_frame_rate (parse, rate, n_subbands * n_blocks, 0, 0);
+
+ sbcparse->alloc_method = alloc_method;
+ sbcparse->ch_mode = ch_mode;
+ sbcparse->rate = rate;
+ sbcparse->n_blocks = n_blocks;
+ sbcparse->n_subbands = n_subbands;
+ sbcparse->bitpool = bitpool;
+
+ gst_caps_unref (caps);
+ }
+
+ if (frame_len > map.size)
+ goto need_more_data;
+
+ GST_BUFFER_OFFSET (frame->buffer) = GST_BUFFER_OFFSET_NONE;
+ GST_BUFFER_OFFSET_END (frame->buffer) = GST_BUFFER_OFFSET_NONE;
+
+ gst_buffer_unmap (frame->buffer, &map);
+ return gst_base_parse_finish_frame (parse, frame, frame_len);
+
+resync:
+ {
+ const guint8 *possible_sync;
+
+ GST_DEBUG_OBJECT (parse, "no sync, resyncing");
+
+ possible_sync = memchr (map.data, SBC_SYNCBYTE, map.size);
+
+ if (possible_sync != NULL)
+ *skipsize = (gint) (possible_sync - map.data);
+ else
+ *skipsize = map.size;
+
+ gst_buffer_unmap (frame->buffer, &map);
+
+ /* we could optimise things here by looping over the data and checking
+ * whether the sync is good or not instead of handing control back to
+ * the base class just to be called again */
+ return GST_FLOW_OK;
+ }
+need_more_data:
+ {
+ GST_LOG_OBJECT (parse, "need %u bytes, but only have %" G_GSIZE_FORMAT,
+ frame_len, map.size);
+ gst_base_parse_set_min_frame_size (parse, frame_len);
+ gst_buffer_unmap (frame->buffer, &map);
+ return GST_FLOW_OK;
+ }
+}
+
+static GstCaps *
+gst_sbc_parse_get_sink_caps (GstBaseParse * parse, GstCaps * filter)
+{
+ GstCaps *peercaps, *templ;
+ GstCaps *res;
+
+ templ = gst_pad_get_pad_template_caps (GST_BASE_PARSE_SINK_PAD (parse));
+ peercaps = gst_pad_peer_query_caps (GST_BASE_PARSE_SRC_PAD (parse), filter);
+
+ if (peercaps) {
+ guint i, n;
+
+ /* Remove the parsed field */
+ peercaps = gst_caps_make_writable (peercaps);
+ n = gst_caps_get_size (peercaps);
+ for (i = 0; i < n; i++) {
+ GstStructure *s = gst_caps_get_structure (peercaps, i);
+
+ gst_structure_remove_field (s, "parsed");
+ }
+
+ res = gst_caps_intersect_full (peercaps, templ, GST_CAPS_INTERSECT_FIRST);
+ gst_caps_unref (peercaps);
+ res = gst_caps_make_writable (res);
+
+ /* Append the template caps because we still want to accept
+ * caps without any fields in the case upstream does not
+ * know anything.
+ */
+ gst_caps_append (res, templ);
+ } else {
+ res = templ;
+ }
+
+ if (filter) {
+ GstCaps *intersection;
+
+ intersection =
+ gst_caps_intersect_full (filter, res, GST_CAPS_INTERSECT_FIRST);
+ gst_caps_unref (res);
+ res = intersection;
+ }
+
+ return res;
+}
+
+static const guint8 crc_table[256] = {
+ 0x00, 0x1D, 0x3A, 0x27, 0x74, 0x69, 0x4E, 0x53,
+ 0xE8, 0xF5, 0xD2, 0xCF, 0x9C, 0x81, 0xA6, 0xBB,
+ 0xCD, 0xD0, 0xF7, 0xEA, 0xB9, 0xA4, 0x83, 0x9E,
+ 0x25, 0x38, 0x1F, 0x02, 0x51, 0x4C, 0x6B, 0x76,
+ 0x87, 0x9A, 0xBD, 0xA0, 0xF3, 0xEE, 0xC9, 0xD4,
+ 0x6F, 0x72, 0x55, 0x48, 0x1B, 0x06, 0x21, 0x3C,
+ 0x4A, 0x57, 0x70, 0x6D, 0x3E, 0x23, 0x04, 0x19,
+ 0xA2, 0xBF, 0x98, 0x85, 0xD6, 0xCB, 0xEC, 0xF1,
+ 0x13, 0x0E, 0x29, 0x34, 0x67, 0x7A, 0x5D, 0x40,
+ 0xFB, 0xE6, 0xC1, 0xDC, 0x8F, 0x92, 0xB5, 0xA8,
+ 0xDE, 0xC3, 0xE4, 0xF9, 0xAA, 0xB7, 0x90, 0x8D,
+ 0x36, 0x2B, 0x0C, 0x11, 0x42, 0x5F, 0x78, 0x65,
+ 0x94, 0x89, 0xAE, 0xB3, 0xE0, 0xFD, 0xDA, 0xC7,
+ 0x7C, 0x61, 0x46, 0x5B, 0x08, 0x15, 0x32, 0x2F,
+ 0x59, 0x44, 0x63, 0x7E, 0x2D, 0x30, 0x17, 0x0A,
+ 0xB1, 0xAC, 0x8B, 0x96, 0xC5, 0xD8, 0xFF, 0xE2,
+ 0x26, 0x3B, 0x1C, 0x01, 0x52, 0x4F, 0x68, 0x75,
+ 0xCE, 0xD3, 0xF4, 0xE9, 0xBA, 0xA7, 0x80, 0x9D,
+ 0xEB, 0xF6, 0xD1, 0xCC, 0x9F, 0x82, 0xA5, 0xB8,
+ 0x03, 0x1E, 0x39, 0x24, 0x77, 0x6A, 0x4D, 0x50,
+ 0xA1, 0xBC, 0x9B, 0x86, 0xD5, 0xC8, 0xEF, 0xF2,
+ 0x49, 0x54, 0x73, 0x6E, 0x3D, 0x20, 0x07, 0x1A,
+ 0x6C, 0x71, 0x56, 0x4B, 0x18, 0x05, 0x22, 0x3F,
+ 0x84, 0x99, 0xBE, 0xA3, 0xF0, 0xED, 0xCA, 0xD7,
+ 0x35, 0x28, 0x0F, 0x12, 0x41, 0x5C, 0x7B, 0x66,
+ 0xDD, 0xC0, 0xE7, 0xFA, 0xA9, 0xB4, 0x93, 0x8E,
+ 0xF8, 0xE5, 0xC2, 0xDF, 0x8C, 0x91, 0xB6, 0xAB,
+ 0x10, 0x0D, 0x2A, 0x37, 0x64, 0x79, 0x5E, 0x43,
+ 0xB2, 0xAF, 0x88, 0x95, 0xC6, 0xDB, 0xFC, 0xE1,
+ 0x5A, 0x47, 0x60, 0x7D, 0x2E, 0x33, 0x14, 0x09,
+ 0x7F, 0x62, 0x45, 0x58, 0x0B, 0x16, 0x31, 0x2C,
+ 0x97, 0x8A, 0xAD, 0xB0, 0xE3, 0xFE, 0xD9, 0xC4
+};
+
+static guint8
+gst_sbc_calculate_crc8 (const guint8 * data, gint crc_bits)
+{
+ guint8 crc = 0x0f;
+ guint8 octet;
+
+ while (crc_bits >= 8) {
+ crc = crc_table[crc ^ *data];
+ crc_bits -= 8;
+ ++data;
+ }
+
+ octet = *data;
+ while (crc_bits > 0) {
+ gchar bit = ((octet ^ crc) & 0x80) >> 7;
+
+ crc = ((crc & 0x7f) << 1) ^ (bit ? 0x1d : 0);
+
+ octet = octet << 1;
+ --crc_bits;
+ }
+
+ return crc;
+}
+
+static gsize
+gst_sbc_calc_framelen (guint subbands, GstSbcChannelMode ch_mode,
+ guint blocks, guint bitpool)
+{
+ switch (ch_mode) {
+ case GST_SBC_CHANNEL_MODE_MONO:
+ return 4 + (subbands * 1) / 2 + (blocks * 1 * bitpool) / 8;
+ case GST_SBC_CHANNEL_MODE_DUAL:
+ return 4 + (subbands * 2) / 2 + (blocks * 2 * bitpool) / 8;
+ case GST_SBC_CHANNEL_MODE_STEREO:
+ return 4 + (subbands * 2) / 2 + (blocks * bitpool) / 8;
+ case GST_SBC_CHANNEL_MODE_JOINT_STEREO:
+ return 4 + (subbands * 2) / 2 + (subbands + blocks * bitpool) / 8;
+ default:
+ break;
+ }
+
+ g_return_val_if_reached (0);
+}
+
+static gsize
+gst_sbc_parse_header (const guint8 * data, guint * rate, guint * n_blocks,
+ GstSbcChannelMode * ch_mode, GstSbcAllocationMethod * alloc_method,
+ guint * n_subbands, guint * bitpool)
+{
+ static const guint16 sbc_rates[4] = { 16000, 32000, 44100, 48000 };
+ static const guint8 sbc_blocks[4] = { 4, 8, 12, 16 };
+ guint8 crc_data[2 + 1 + 8], crc_bits, i;
+
+ GST_MEMDUMP ("header", data, 8);
+
+ if (data[0] != SBC_SYNCBYTE)
+ return 0;
+
+ *rate = sbc_rates[(data[1] >> 6) & 0x03];
+ *n_blocks = sbc_blocks[(data[1] >> 4) & 0x03];
+ *ch_mode = (GstSbcChannelMode) ((data[1] >> 2) & 0x03);
+ *alloc_method = (data[1] >> 1) & 0x01;
+ *n_subbands = (data[1] & 0x01) ? 8 : 4;
+ *bitpool = data[2];
+
+ GST_TRACE ("rate=%u, n_blocks=%u, ch_mode=%u, alloc_method=%u, "
+ "n_subbands=%u, bitpool=%u", *rate, *n_blocks, *ch_mode, *alloc_method,
+ *n_subbands, *bitpool);
+
+ if (*bitpool < 2)
+ return 0;
+
+ /* check CRC */
+ crc_data[0] = data[1];
+ crc_data[1] = data[2];
+ crc_bits = 16;
+
+ /* joint flags and RFA */
+ if (*ch_mode == GST_SBC_CHANNEL_MODE_JOINT_STEREO)
+ crc_bits += *n_subbands;
+
+ /* scale factors */
+ if (*ch_mode == GST_SBC_CHANNEL_MODE_MONO)
+ crc_bits += *n_subbands * 1 * 4;
+ else
+ crc_bits += *n_subbands * 2 * 4;
+
+ for (i = 16; i < crc_bits; i += 8) {
+ crc_data[i / 8] = data[1 + (i / 8) + 1];
+ }
+
+ if (i > crc_bits) {
+ crc_data[(i / 8) - 1] &= 0xF0;
+ }
+
+ GST_MEMDUMP ("crc bytes", crc_data, GST_ROUND_UP_8 (crc_bits) / 8);
+ if (gst_sbc_calculate_crc8 (crc_data, crc_bits) != data[3]) {
+ GST_LOG ("header CRC check failed, bits=%u, got 0x%02x, expected 0x%02x",
+ crc_bits, gst_sbc_calculate_crc8 (crc_data, crc_bits), data[3]);
+ return 0;
+ }
+
+ return gst_sbc_calc_framelen (*n_subbands, *ch_mode, *n_blocks, *bitpool);
+}
projects / platform / upstream / gst-plugins-good.git / commitdiff