/* GStreamer * Copyright (C) 2009 Pioneers of the Inevitable * * Authors: Michael Smith * * 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. */ /* Based on ADPCM decoders in libsndfile, Copyright (C) 1999-2002 Erik de Castro Lopo #include #define GST_TYPE_ADPCM_DEC \ (adpcmdec_get_type ()) #define GST_ADPCM_DEC(obj) \ (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ADPCM_DEC, ADPCMDec)) #define GST_CAT_DEFAULT adpcmdec_debug GST_DEBUG_CATEGORY_STATIC (adpcmdec_debug); static GstStaticPadTemplate adpcmdec_sink_template = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-adpcm, " " layout=(string){microsoft, dvi}, " " block_align = (int) [64, 8192], " " rate = (int)[ 1, MAX ], " "channels = (int)[1,2];") ); static GstStaticPadTemplate adpcmdec_src_template = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-raw, " "format = (string) " GST_AUDIO_NE (S16) ", " "layout = (string) interleaved, " "rate = (int) [1, MAX], channels = (int) [1,2]") ); enum adpcm_layout { LAYOUT_ADPCM_MICROSOFT, LAYOUT_ADPCM_DVI }; typedef struct _ADPCMDecClass { GstAudioDecoderClass parent_class; } ADPCMDecClass; typedef struct _ADPCMDec { GstAudioDecoder parent; enum adpcm_layout layout; int rate; int channels; int blocksize; } ADPCMDec; GType adpcmdec_get_type (void); G_DEFINE_TYPE (ADPCMDec, adpcmdec, GST_TYPE_AUDIO_DECODER); static gboolean adpcmdec_set_format (GstAudioDecoder * bdec, GstCaps * in_caps) { ADPCMDec *dec = (ADPCMDec *) (bdec); GstStructure *structure = gst_caps_get_structure (in_caps, 0); const gchar *layout; GstAudioInfo info; layout = gst_structure_get_string (structure, "layout"); if (!layout) return FALSE; if (g_str_equal (layout, "microsoft")) dec->layout = LAYOUT_ADPCM_MICROSOFT; else if (g_str_equal (layout, "dvi")) dec->layout = LAYOUT_ADPCM_DVI; else return FALSE; if (!gst_structure_get_int (structure, "block_align", &dec->blocksize)) dec->blocksize = -1; /* Not provided */ if (!gst_structure_get_int (structure, "rate", &dec->rate)) return FALSE; if (!gst_structure_get_int (structure, "channels", &dec->channels)) return FALSE; gst_audio_info_init (&info); gst_audio_info_set_format (&info, GST_AUDIO_FORMAT_S16, dec->rate, dec->channels, NULL); gst_audio_decoder_set_output_format (bdec, &info); return TRUE; } /*===================================================================== * From libsndfile: * * MS ADPCM Block Layout. * ====================== * Block is usually 256, 512 or 1024 bytes depending on sample rate. * For a mono file, the block is laid out as follows: * byte purpose * 0 block predictor [0..6] * 1,2 initial idelta (positive) * 3,4 sample 1 * 5,6 sample 0 * 7..n packed bytecodes * * For a stereo file, the block is laid out as follows: * byte purpose * 0 block predictor [0..6] for left channel * 1 block predictor [0..6] for right channel * 2,3 initial idelta (positive) for left channel * 4,5 initial idelta (positive) for right channel * 6,7 sample 1 for left channel * 8,9 sample 1 for right channel * 10,11 sample 0 for left channel * 12,13 sample 0 for right channel * 14..n packed bytecodes * *===================================================================== */ static const int AdaptationTable[] = { 230, 230, 230, 230, 307, 409, 512, 614, 768, 614, 512, 409, 307, 230, 230, 230 }; static const int AdaptCoeff1[] = { 256, 512, 0, 192, 240, 460, 392 }; static const int AdaptCoeff2[] = { 0, -256, 0, 64, 0, -208, -232 }; static gint16 read_sample (const guint8 * data) { guint16 val = data[0] | (data[1] << 8); return *((gint16 *) & val); } /* Decode a single block of data from 'data', storing 'n_samples' decoded 16 bit samples in 'samples'. All buffer lengths have been verified by the caller */ static gboolean adpcmdec_decode_ms_block (ADPCMDec * dec, int n_samples, const guint8 * data, gint16 * samples) { gint16 pred[2]; gint16 idelta[2]; int idx; /* Current byte offset in 'data' */ int i; /* Current sample index in 'samples' */ /* Read the block header, verify for sanity */ if (dec->channels == 1) { pred[0] = data[0]; idelta[0] = read_sample (data + 1); samples[1] = read_sample (data + 3); samples[0] = read_sample (data + 5); idx = 7; i = 2; if (pred[0] < 0 || pred[0] > 6) { GST_WARNING_OBJECT (dec, "Invalid block predictor"); return FALSE; } } else { pred[0] = data[0]; pred[1] = data[1]; idelta[0] = read_sample (data + 2); idelta[1] = read_sample (data + 4); samples[2] = read_sample (data + 6); samples[3] = read_sample (data + 8); samples[0] = read_sample (data + 10); samples[1] = read_sample (data + 12); idx = 14; i = 4; if (pred[0] < 0 || pred[0] > 6 || pred[1] < 0 || pred[1] > 6) { GST_WARNING_OBJECT (dec, "Invalid block predictor"); return FALSE; } } for (; i < n_samples; i++) { int chan = i % dec->channels; int bytecode; int delta; int current; int predict; if (i % 2 == 0) { bytecode = (data[idx] >> 4) & 0x0F; } else { bytecode = data[idx] & 0x0F; idx++; } delta = idelta[chan]; idelta[chan] = (AdaptationTable[bytecode] * delta) >> 8; if (idelta[chan] < 16) idelta[chan] = 16; /* Bytecode is used above as an index into the table. Below, it's used as a signed 4-bit value; convert appropriately */ if (bytecode & 0x8) bytecode -= 0x10; predict = ((samples[i - dec->channels] * AdaptCoeff1[pred[chan]]) + (samples[i - 2 * dec->channels] * AdaptCoeff2[pred[chan]]) ) >> 8; current = (bytecode * delta) + predict; /* Clamp to 16 bits, store decoded sample */ samples[i] = CLAMP (current, G_MININT16, G_MAXINT16); } return TRUE; } static const int ima_indx_adjust[16] = { -1, -1, -1, -1, 2, 4, 6, 8, -1, -1, -1, -1, 2, 4, 6, 8, }; static const int ima_step_size[89] = { 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767 }; /* Decode a single block of data from 'data', storing 'n_samples' decoded 16 bit samples in 'samples'. All buffer lengths have been verified by the caller */ static gboolean adpcmdec_decode_ima_block (ADPCMDec * dec, int n_samples, const guint8 * data, gint16 * samples) { gint16 stepindex[2]; int channel; int idx; int i, j; int sample; if ((n_samples - dec->channels) % 8 != 0) { GST_WARNING_OBJECT (dec, "Input not correct size"); return FALSE; } for (channel = 0; channel < dec->channels; channel++) { samples[channel] = read_sample (data + channel * 4); stepindex[channel] = MIN (data[channel * 4 + 2], 88); if (data[channel * 4 + 3] != 0) { GST_WARNING_OBJECT (dec, "Synchronisation error"); return FALSE; } } i = dec->channels; idx = 4 * dec->channels; while (i < n_samples) { for (channel = 0; channel < dec->channels; channel++) { sample = i + channel; for (j = 0; j < 8; j++) { int bytecode; int step; int diff; if (j % 2 == 0) { bytecode = data[idx] & 0x0F; } else { bytecode = (data[idx] >> 4) & 0x0F; idx++; } step = ima_step_size[stepindex[channel]]; diff = (2 * (bytecode & 0x7) * step + step) / 8; if (bytecode & 8) diff = -diff; samples[sample] = CLAMP (samples[sample - dec->channels] + diff, G_MININT16, G_MAXINT16); stepindex[channel] = CLAMP (stepindex[channel] + ima_indx_adjust[bytecode], 0, 88); sample += dec->channels; } } i += 8 * dec->channels; } return TRUE; } static GstBuffer * adpcmdec_decode_block (ADPCMDec * dec, const guint8 * data, int blocksize) { gboolean res = FALSE; GstBuffer *outbuf = NULL; int outsize; int samples; GstMapInfo omap; if (dec->layout == LAYOUT_ADPCM_MICROSOFT) { /* Each block has a 3 byte header per channel, plus 4 bytes per channel to give two initial sample values per channel. Then the remainder gives two samples per byte */ if (blocksize < 7 * dec->channels) goto exit; samples = (blocksize - 7 * dec->channels) * 2 + 2 * dec->channels; outsize = 2 * samples; outbuf = gst_buffer_new_and_alloc (outsize); gst_buffer_map (outbuf, &omap, GST_MAP_WRITE); res = adpcmdec_decode_ms_block (dec, samples, data, (gint16 *) omap.data); gst_buffer_unmap (outbuf, &omap); } else if (dec->layout == LAYOUT_ADPCM_DVI) { /* Each block has a 4 byte header per channel, include an initial sample. Then the remainder gives two samples per byte */ if (blocksize < 4 * dec->channels) goto exit; samples = (blocksize - 4 * dec->channels) * 2 + dec->channels; outsize = 2 * samples; outbuf = gst_buffer_new_and_alloc (outsize); gst_buffer_map (outbuf, &omap, GST_MAP_WRITE); res = adpcmdec_decode_ima_block (dec, samples, data, (gint16 *) omap.data); gst_buffer_unmap (outbuf, &omap); } else { GST_WARNING_OBJECT (dec, "Unknown layout"); } if (!res) { if (outbuf) gst_buffer_unref (outbuf); outbuf = NULL; GST_WARNING_OBJECT (dec, "Decode of block failed"); } exit: return outbuf; } static GstFlowReturn adpcmdec_parse (GstAudioDecoder * bdec, GstAdapter * adapter, gint * offset, gint * length) { ADPCMDec *dec = (ADPCMDec *) (bdec); guint size; size = gst_adapter_available (adapter); g_return_val_if_fail (size > 0, GST_FLOW_ERROR); if (dec->blocksize < 0) { /* No explicit blocksize; we just process one input buffer at a time */ *offset = 0; *length = size; } else { if (size >= dec->blocksize) { *offset = 0; *length = dec->blocksize; } else { return GST_FLOW_EOS; } } return GST_FLOW_OK; } static GstFlowReturn adpcmdec_handle_frame (GstAudioDecoder * bdec, GstBuffer * buffer) { ADPCMDec *dec = (ADPCMDec *) (bdec); GstFlowReturn ret = GST_FLOW_OK; GstMapInfo map; GstBuffer *outbuf = NULL; /* no fancy draining */ if (G_UNLIKELY (!buffer)) return GST_FLOW_OK; if (!dec->blocksize) return GST_FLOW_NOT_NEGOTIATED; gst_buffer_map (buffer, &map, GST_MAP_READ); outbuf = adpcmdec_decode_block (dec, map.data, dec->blocksize); gst_buffer_unmap (buffer, &map); if (outbuf == NULL) { GST_AUDIO_DECODER_ERROR (bdec, 1, STREAM, DECODE, (NULL), ("frame decode failed"), ret); } if (ret == GST_FLOW_OK) ret = gst_audio_decoder_finish_frame (bdec, outbuf, 1); return ret; } static gboolean adpcmdec_start (GstAudioDecoder * bdec) { ADPCMDec *dec = (ADPCMDec *) bdec; GST_DEBUG_OBJECT (dec, "start"); dec->blocksize = 0; dec->rate = 0; dec->channels = 0; return TRUE; } static gboolean adpcmdec_stop (GstAudioDecoder * dec) { GST_DEBUG_OBJECT (dec, "stop"); return TRUE; } static void adpcmdec_init (ADPCMDec * dec) { gst_audio_decoder_set_needs_format (GST_AUDIO_DECODER (dec), TRUE); gst_audio_decoder_set_use_default_pad_acceptcaps (GST_AUDIO_DECODER_CAST (dec), TRUE); GST_PAD_SET_ACCEPT_TEMPLATE (GST_AUDIO_DECODER_SINK_PAD (dec)); } static void adpcmdec_class_init (ADPCMDecClass * klass) { GstElementClass *element_class = (GstElementClass *) klass; GstAudioDecoderClass *base_class = (GstAudioDecoderClass *) klass; gst_element_class_add_pad_template (element_class, gst_static_pad_template_get (&adpcmdec_sink_template)); gst_element_class_add_pad_template (element_class, gst_static_pad_template_get (&adpcmdec_src_template)); gst_element_class_set_static_metadata (element_class, "ADPCM decoder", "Codec/Decoder/Audio", "Decode MS and IMA ADPCM audio", "Pioneers of the Inevitable "); base_class->start = GST_DEBUG_FUNCPTR (adpcmdec_start); base_class->stop = GST_DEBUG_FUNCPTR (adpcmdec_stop); base_class->set_format = GST_DEBUG_FUNCPTR (adpcmdec_set_format); base_class->parse = GST_DEBUG_FUNCPTR (adpcmdec_parse); base_class->handle_frame = GST_DEBUG_FUNCPTR (adpcmdec_handle_frame); } static gboolean plugin_init (GstPlugin * plugin) { GST_DEBUG_CATEGORY_INIT (adpcmdec_debug, "adpcmdec", 0, "ADPCM Decoders"); if (!gst_element_register (plugin, "adpcmdec", GST_RANK_PRIMARY, GST_TYPE_ADPCM_DEC)) { return FALSE; } return TRUE; } GST_PLUGIN_DEFINE (GST_VERSION_MAJOR, GST_VERSION_MINOR, adpcmdec, "ADPCM decoder", plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);