/* GStreamer SBC audio decoder * * Copyright (C) 2004-2010 Marcel Holtmann <marcel@holtmann.org> * Copyright (C) 2013 Tim-Philipp Müller <tim centricular net> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser 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 * */ /** * SECTION:element-sbdec * * This element decodes a Bluetooth SBC audio streams to raw integer PCM audio * * <refsect2> * <title>Example pipelines</title> * |[ * gst-launch-1.0 -v filesrc location=audio.sbc ! sbcparse ! sbcdec ! audioconvert ! audioresample ! autoaudiosink * ]| Decode a raw SBC file. * </refsect2> */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <string.h> #include "gstsbcdec.h" /* FIXME: where does this come from? how is it derived? */ #define BUF_SIZE 8192 GST_DEBUG_CATEGORY_STATIC (sbc_dec_debug); #define GST_CAT_DEFAULT sbc_dec_debug #define parent_class gst_sbc_dec_parent_class G_DEFINE_TYPE (GstSbcDec, gst_sbc_dec, GST_TYPE_AUDIO_DECODER); static GstStaticPadTemplate sbc_dec_sink_factory = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-sbc, channels = (int) [ 1, 2 ], " "rate = (int) { 16000, 32000, 44100, 48000 }, " "parsed = (boolean) true")); static GstStaticPadTemplate sbc_dec_src_factory = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-raw, format=" GST_AUDIO_NE (S16) ", " "rate = (int) { 16000, 32000, 44100, 48000 }, " "channels = (int) [ 1, 2 ], layout=interleaved")); static GstFlowReturn gst_sbc_dec_handle_frame (GstAudioDecoder * audio_dec, GstBuffer * buf) { GstSbcDec *dec = GST_SBC_DEC (audio_dec); GstBuffer *outbuf = NULL; GstMapInfo out_map; GstMapInfo in_map; gsize output_size; guint num_frames, i; /* no fancy draining */ if (G_UNLIKELY (buf == NULL)) return GST_FLOW_OK; gst_buffer_map (buf, &in_map, GST_MAP_READ); if (G_UNLIKELY (in_map.size == 0)) goto done; /* we assume all frames are of the same size, this is implied by the * input caps applying to the whole input buffer, and the parser should * also have made sure of that */ if (G_UNLIKELY (in_map.size % dec->frame_len != 0)) goto mixed_frames; num_frames = in_map.size / dec->frame_len; output_size = num_frames * dec->samples_per_frame * sizeof (gint16); outbuf = gst_audio_decoder_allocate_output_buffer (audio_dec, output_size); if (outbuf == NULL) goto no_buffer; gst_buffer_map (outbuf, &out_map, GST_MAP_WRITE); for (i = 0; i < num_frames; ++i) { gssize ret; gsize written; ret = sbc_decode (&dec->sbc, in_map.data + (i * dec->frame_len), dec->frame_len, out_map.data + (i * dec->samples_per_frame * 2), dec->samples_per_frame * 2, &written); if (ret <= 0 || written != (dec->samples_per_frame * 2)) { GST_WARNING_OBJECT (dec, "decoding error, ret = %" G_GSSIZE_FORMAT ", " "written = %" G_GSSIZE_FORMAT, ret, written); break; } } gst_buffer_unmap (outbuf, &out_map); if (i > 0) gst_buffer_set_size (outbuf, i * dec->samples_per_frame * 2); else gst_buffer_replace (&outbuf, NULL); done: gst_buffer_unmap (buf, &in_map); return gst_audio_decoder_finish_frame (audio_dec, outbuf, 1); /* ERRORS */ mixed_frames: { GST_WARNING_OBJECT (dec, "inconsistent input data/frames, skipping"); goto done; } no_buffer: { GST_ERROR_OBJECT (dec, "could not allocate output buffer"); goto done; } } static gboolean gst_sbc_dec_set_format (GstAudioDecoder * audio_dec, GstCaps * caps) { GstSbcDec *dec = GST_SBC_DEC (audio_dec); const gchar *channel_mode; GstAudioInfo info; GstStructure *s; gint channels, rate, subbands, blocks, bitpool; s = gst_caps_get_structure (caps, 0); gst_structure_get_int (s, "channels", &channels); gst_structure_get_int (s, "rate", &rate); /* save input format */ channel_mode = gst_structure_get_string (s, "channel-mode"); if (channel_mode == NULL || !gst_structure_get_int (s, "subbands", &subbands) || !gst_structure_get_int (s, "blocks", &blocks) || !gst_structure_get_int (s, "bitpool", &bitpool)) return FALSE; if (strcmp (channel_mode, "mono") == 0) { dec->frame_len = 4 + (subbands * 1) / 2 + (blocks * 1 * bitpool) / 8; } else if (strcmp (channel_mode, "dual") == 0) { dec->frame_len = 4 + (subbands * 2) / 2 + (blocks * 2 * bitpool) / 8; } else if (strcmp (channel_mode, "stereo") == 0) { dec->frame_len = 4 + (subbands * 2) / 2 + (blocks * bitpool) / 8; } else if (strcmp (channel_mode, "joint") == 0) { dec->frame_len = 4 + (subbands * 2) / 2 + (subbands + blocks * bitpool) / 8; } else { return FALSE; } dec->samples_per_frame = channels * blocks * subbands; GST_INFO_OBJECT (dec, "frame len: %" G_GSIZE_FORMAT ", samples per frame " "%" G_GSIZE_FORMAT, dec->frame_len, dec->samples_per_frame); /* set up output format */ gst_audio_info_init (&info); gst_audio_info_set_format (&info, GST_AUDIO_FORMAT_S16, rate, channels, NULL); gst_audio_decoder_set_output_format (audio_dec, &info); return TRUE; } static gboolean gst_sbc_dec_start (GstAudioDecoder * dec) { GstSbcDec *sbcdec = GST_SBC_DEC (dec); GST_INFO_OBJECT (dec, "Setup subband codec"); sbc_init (&sbcdec->sbc, 0); return TRUE; } static gboolean gst_sbc_dec_stop (GstAudioDecoder * dec) { GstSbcDec *sbcdec = GST_SBC_DEC (dec); GST_INFO_OBJECT (sbcdec, "Finish subband codec"); sbc_finish (&sbcdec->sbc); sbcdec->samples_per_frame = 0; sbcdec->frame_len = 0; return TRUE; } static void gst_sbc_dec_class_init (GstSbcDecClass * klass) { GstAudioDecoderClass *audio_decoder_class = (GstAudioDecoderClass *) klass; GstElementClass *element_class = (GstElementClass *) klass; audio_decoder_class->start = GST_DEBUG_FUNCPTR (gst_sbc_dec_start); audio_decoder_class->stop = GST_DEBUG_FUNCPTR (gst_sbc_dec_stop); audio_decoder_class->set_format = GST_DEBUG_FUNCPTR (gst_sbc_dec_set_format); audio_decoder_class->handle_frame = GST_DEBUG_FUNCPTR (gst_sbc_dec_handle_frame); gst_element_class_add_pad_template (element_class, gst_static_pad_template_get (&sbc_dec_sink_factory)); gst_element_class_add_pad_template (element_class, gst_static_pad_template_get (&sbc_dec_src_factory)); gst_element_class_set_static_metadata (element_class, "Bluetooth SBC audio decoder", "Codec/Decoder/Audio", "Decode an SBC audio stream", "Marcel Holtmann <marcel@holtmann.org>"); GST_DEBUG_CATEGORY_INIT (sbc_dec_debug, "sbcdec", 0, "SBC decoding element"); } static void gst_sbc_dec_init (GstSbcDec * dec) { gst_audio_decoder_set_needs_format (GST_AUDIO_DECODER (dec), TRUE); dec->samples_per_frame = 0; dec->frame_len = 0; }