aboutsummaryrefslogtreecommitdiffstats
path: root/src/decoder/plugins/OpusDecoderPlugin.cxx
blob: 983d17278d5a7673d2ef150809ce3ec1554f79fc (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
/*
 * Copyright (C) 2003-2014 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h" /* must be first for large file support */
#include "OpusDecoderPlugin.h"
#include "OpusDomain.hxx"
#include "OpusHead.hxx"
#include "OpusTags.hxx"
#include "OggFind.hxx"
#include "OggSyncState.hxx"
#include "../DecoderAPI.hxx"
#include "OggCodec.hxx"
#include "tag/TagHandler.hxx"
#include "tag/TagBuilder.hxx"
#include "input/InputStream.hxx"
#include "util/Error.hxx"
#include "Log.hxx"

#include <opus.h>
#include <ogg/ogg.h>

#include <string.h>

static constexpr opus_int32 opus_sample_rate = 48000;

gcc_pure
static bool
IsOpusHead(const ogg_packet &packet)
{
	return packet.bytes >= 8 && memcmp(packet.packet, "OpusHead", 8) == 0;
}

gcc_pure
static bool
IsOpusTags(const ogg_packet &packet)
{
	return packet.bytes >= 8 && memcmp(packet.packet, "OpusTags", 8) == 0;
}

static bool
mpd_opus_init(gcc_unused const config_param &param)
{
	LogDebug(opus_domain, opus_get_version_string());

	return true;
}

class MPDOpusDecoder {
	Decoder &decoder;
	InputStream &input_stream;

	ogg_stream_state os;

	OpusDecoder *opus_decoder;
	opus_int16 *output_buffer;
	unsigned output_size;

	bool os_initialized;
	bool found_opus;

	int opus_serialno;

	ogg_int64_t eos_granulepos;

	size_t frame_size;

public:
	MPDOpusDecoder(Decoder &_decoder,
		       InputStream &_input_stream)
		:decoder(_decoder), input_stream(_input_stream),
		 opus_decoder(nullptr),
		 output_buffer(nullptr), output_size(0),
		 os_initialized(false), found_opus(false) {}
	~MPDOpusDecoder();

	bool ReadFirstPage(OggSyncState &oy);
	bool ReadNextPage(OggSyncState &oy);

	DecoderCommand HandlePackets();
	DecoderCommand HandlePacket(const ogg_packet &packet);
	DecoderCommand HandleBOS(const ogg_packet &packet);
	DecoderCommand HandleTags(const ogg_packet &packet);
	DecoderCommand HandleAudio(const ogg_packet &packet);

	bool Seek(OggSyncState &oy, double where);
};

MPDOpusDecoder::~MPDOpusDecoder()
{
	delete[] output_buffer;

	if (opus_decoder != nullptr)
		opus_decoder_destroy(opus_decoder);

	if (os_initialized)
		ogg_stream_clear(&os);
}

inline bool
MPDOpusDecoder::ReadFirstPage(OggSyncState &oy)
{
	assert(!os_initialized);

	if (!oy.ExpectFirstPage(os))
		return false;

	os_initialized = true;
	return true;
}

inline bool
MPDOpusDecoder::ReadNextPage(OggSyncState &oy)
{
	assert(os_initialized);

	ogg_page page;
	if (!oy.ExpectPage(page))
		return false;

	const auto page_serialno = ogg_page_serialno(&page);
	if (page_serialno != os.serialno)
		ogg_stream_reset_serialno(&os, page_serialno);

	ogg_stream_pagein(&os, &page);
	return true;
}

inline DecoderCommand
MPDOpusDecoder::HandlePackets()
{
	ogg_packet packet;
	while (ogg_stream_packetout(&os, &packet) == 1) {
		auto cmd = HandlePacket(packet);
		if (cmd != DecoderCommand::NONE)
			return cmd;
	}

	return DecoderCommand::NONE;
}

inline DecoderCommand
MPDOpusDecoder::HandlePacket(const ogg_packet &packet)
{
	if (packet.e_o_s)
		return DecoderCommand::STOP;

	if (packet.b_o_s)
		return HandleBOS(packet);
	else if (!found_opus)
		return DecoderCommand::STOP;

	if (IsOpusTags(packet))
		return HandleTags(packet);

	return HandleAudio(packet);
}

/**
 * Load the end-of-stream packet and restore the previous file
 * position.
 */
static bool
LoadEOSPacket(InputStream &is, Decoder *decoder, int serialno,
	      ogg_packet &packet)
{
	if (!is.CheapSeeking())
		/* we do this for local files only, because seeking
		   around remote files is expensive and not worth the
		   troubl */
		return -1;

	const auto old_offset = is.GetOffset();
	if (old_offset < 0)
		return -1;

	/* create temporary Ogg objects for seeking and parsing the
	   EOS packet */
	OggSyncState oy(is, decoder);
	ogg_stream_state os;
	ogg_stream_init(&os, serialno);

	bool result = OggSeekFindEOS(oy, os, packet, is);
	ogg_stream_clear(&os);

	/* restore the previous file position */
	is.Seek(old_offset, SEEK_SET, IgnoreError());

	return result;
}

/**
 * Load the end-of-stream granulepos and restore the previous file
 * position.
 *
 * @return -1 on error
 */
gcc_pure
static ogg_int64_t
LoadEOSGranulePos(InputStream &is, Decoder *decoder, int serialno)
{
	ogg_packet packet;
	if (!LoadEOSPacket(is, decoder, serialno, packet))
		return -1;

	return packet.granulepos;
}

inline DecoderCommand
MPDOpusDecoder::HandleBOS(const ogg_packet &packet)
{
	assert(packet.b_o_s);

	if (found_opus || !IsOpusHead(packet))
		return DecoderCommand::STOP;

	unsigned channels;
	if (!ScanOpusHeader(packet.packet, packet.bytes, channels) ||
	    !audio_valid_channel_count(channels))
		return DecoderCommand::STOP;

	assert(opus_decoder == nullptr);
	assert(output_buffer == nullptr);

	opus_serialno = os.serialno;
	found_opus = true;

	/* TODO: parse attributes from the OpusHead (sample rate,
	   channels, ...) */

	int opus_error;
	opus_decoder = opus_decoder_create(opus_sample_rate, channels,
					   &opus_error);
	if (opus_decoder == nullptr) {
		FormatError(opus_domain, "libopus error: %s",
			    opus_strerror(opus_error));
		return DecoderCommand::STOP;
	}

	eos_granulepos = LoadEOSGranulePos(input_stream, &decoder,
					   opus_serialno);
	const double duration = eos_granulepos >= 0
		? double(eos_granulepos) / opus_sample_rate
		: -1.0;

	const AudioFormat audio_format(opus_sample_rate,
				       SampleFormat::S16, channels);
	decoder_initialized(decoder, audio_format,
			    eos_granulepos > 0, duration);
	frame_size = audio_format.GetFrameSize();

	/* allocate an output buffer for 16 bit PCM samples big enough
	   to hold a quarter second, larger than 120ms required by
	   libopus */
	output_size = audio_format.sample_rate / 4;
	output_buffer = new opus_int16[output_size * audio_format.channels];

	return decoder_get_command(decoder);
}

inline DecoderCommand
MPDOpusDecoder::HandleTags(const ogg_packet &packet)
{
	ReplayGainInfo rgi;
	rgi.Clear();

	TagBuilder tag_builder;

	DecoderCommand cmd;
	if (ScanOpusTags(packet.packet, packet.bytes,
			 &rgi,
			 &add_tag_handler, &tag_builder) &&
	    !tag_builder.IsEmpty()) {
		decoder_replay_gain(decoder, &rgi);

		Tag tag = tag_builder.Commit();
		cmd = decoder_tag(decoder, input_stream, std::move(tag));
	} else
		cmd = decoder_get_command(decoder);

	return cmd;
}

inline DecoderCommand
MPDOpusDecoder::HandleAudio(const ogg_packet &packet)
{
	assert(opus_decoder != nullptr);

	int nframes = opus_decode(opus_decoder,
				  (const unsigned char*)packet.packet,
				  packet.bytes,
				  output_buffer, output_size,
				  0);
	if (nframes < 0) {
		LogError(opus_domain, opus_strerror(nframes));
		return DecoderCommand::STOP;
	}

	if (nframes > 0) {
		const size_t nbytes = nframes * frame_size;
		auto cmd = decoder_data(decoder, input_stream,
					output_buffer, nbytes,
					0);
		if (cmd != DecoderCommand::NONE)
			return cmd;

		if (packet.granulepos > 0)
			decoder_timestamp(decoder,
					  double(packet.granulepos)
					  / opus_sample_rate);
	}

	return DecoderCommand::NONE;
}

bool
MPDOpusDecoder::Seek(OggSyncState &oy, double where_s)
{
	assert(eos_granulepos > 0);
	assert(input_stream.IsSeekable());
	assert(input_stream.KnownSize());
	assert(input_stream.GetOffset() >= 0);

	const ogg_int64_t where_granulepos(where_s * opus_sample_rate);

	/* interpolate the file offset where we expect to find the
	   given granule position */
	/* TODO: implement binary search */
	InputStream::offset_type offset(where_granulepos * input_stream.GetSize()
					/ eos_granulepos);

	if (!OggSeekPageAtOffset(oy, os, input_stream, offset, SEEK_SET))
		return false;

	decoder_timestamp(decoder, where_s);
	return true;
}

static void
mpd_opus_stream_decode(Decoder &decoder,
		       InputStream &input_stream)
{
	if (ogg_codec_detect(&decoder, input_stream) != OGG_CODEC_OPUS)
		return;

	/* rewind the stream, because ogg_codec_detect() has
	   moved it */
	input_stream.LockRewind(IgnoreError());

	MPDOpusDecoder d(decoder, input_stream);
	OggSyncState oy(input_stream, &decoder);

	if (!d.ReadFirstPage(oy))
		return;

	while (true) {
		auto cmd = d.HandlePackets();
		if (cmd == DecoderCommand::SEEK) {
			if (d.Seek(oy, decoder_seek_where(decoder)))
				decoder_command_finished(decoder);
			else
				decoder_seek_error(decoder);

			continue;
		}

		if (cmd != DecoderCommand::NONE)
			break;

		if (!d.ReadNextPage(oy))
			break;
	}
}

static bool
mpd_opus_scan_stream(InputStream &is,
		     const struct tag_handler *handler, void *handler_ctx)
{
	OggSyncState oy(is);

	ogg_stream_state os;
	if (!oy.ExpectFirstPage(os))
		return false;

	/* read at most two more pages */
	unsigned remaining_pages = 2;

	bool result = false;

	ogg_packet packet;
	while (true) {
		int r = ogg_stream_packetout(&os, &packet);
		if (r < 0) {
			result = false;
			break;
		}

		if (r == 0) {
			if (remaining_pages-- == 0)
				break;

			if (!oy.ExpectPageIn(os)) {
				result = false;
				break;
			}

			continue;
		}

		if (packet.b_o_s) {
			if (!IsOpusHead(packet))
				break;

			unsigned channels;
			if (!ScanOpusHeader(packet.packet, packet.bytes, channels) ||
			    !audio_valid_channel_count(channels)) {
				result = false;
				break;
			}

			result = true;
		} else if (!result)
			break;
		else if (IsOpusTags(packet)) {
			if (!ScanOpusTags(packet.packet, packet.bytes,
					  nullptr,
					  handler, handler_ctx))
				result = false;

			break;
		}
	}

	if (packet.e_o_s || OggSeekFindEOS(oy, os, packet, is))
		tag_handler_invoke_duration(handler, handler_ctx,
					    packet.granulepos / opus_sample_rate);

	ogg_stream_clear(&os);

	return result;
}

static const char *const opus_suffixes[] = {
	"opus",
	"ogg",
	"oga",
	nullptr
};

static const char *const opus_mime_types[] = {
	"audio/opus",
	nullptr
};

const struct DecoderPlugin opus_decoder_plugin = {
	"opus",
	mpd_opus_init,
	nullptr,
	mpd_opus_stream_decode,
	nullptr,
	nullptr,
	mpd_opus_scan_stream,
	nullptr,
	opus_suffixes,
	opus_mime_types,
};