path: root/libavcodec/opus.c (plain)
blob: 5847e88e11d3e01bc5f860615564b128686327e3

1	/*
2	* Copyright (c) 2012 Andrew D'Addesio
3	* Copyright (c) 2013-2014 Mozilla Corporation
4	*
5	* This file is part of FFmpeg.
6	*
7	* FFmpeg is free software; you can redistribute it and/or
8	* modify it under the terms of the GNU Lesser General Public
9	* License as published by the Free Software Foundation; either
10	* version 2.1 of the License, or (at your option) any later version.
11	*
12	* FFmpeg is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15	* Lesser General Public License for more details.
16	*
17	* You should have received a copy of the GNU Lesser General Public
18	* License along with FFmpeg; if not, write to the Free Software
19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	*/
21
22	/**
23	* @file
24	* Opus decoder/parser shared code
25	*/
26
27	#include <stdint.h>
28
29	#include "libavutil/error.h"
30	#include "libavutil/ffmath.h"
31
32	#include "opus.h"
33	#include "vorbis.h"
34
35	static const uint16_t opus_frame_duration[32] = {
36	480, 960, 1920, 2880,
37	480, 960, 1920, 2880,
38	480, 960, 1920, 2880,
39	480, 960,
40	480, 960,
41	120, 240, 480, 960,
42	120, 240, 480, 960,
43	120, 240, 480, 960,
44	120, 240, 480, 960,
45	};
46
47	/**
48	* Read a 1- or 2-byte frame length
49	*/
50	static inline int xiph_lacing_16bit(const uint8_t **ptr, const uint8_t *end)
51	{
52	int val;
53
54	if (*ptr >= end)
55	return AVERROR_INVALIDDATA;
56	val = *(*ptr)++;
57	if (val >= 252) {
58	if (*ptr >= end)
59	return AVERROR_INVALIDDATA;
60	val += 4 * *(*ptr)++;
61	}
62	return val;
63	}
64
65	/**
66	* Read a multi-byte length (used for code 3 packet padding size)
67	*/
68	static inline int xiph_lacing_full(const uint8_t **ptr, const uint8_t *end)
69	{
70	int val = 0;
71	int next;
72
73	while (1) {
74	if (*ptr >= end || val > INT_MAX - 254)
75	return AVERROR_INVALIDDATA;
76	next = *(*ptr)++;
77	val += next;
78	if (next < 255)
79	break;
80	else
81	val--;
82	}
83	return val;
84	}
85
86	/**
87	* Parse Opus packet info from raw packet data
88	*/
89	int ff_opus_parse_packet(OpusPacket *pkt, const uint8_t *buf, int buf_size,
90	int self_delimiting)
91	{
92	const uint8_t *ptr = buf;
93	const uint8_t *end = buf + buf_size;
94	int padding = 0;
95	int frame_bytes, i;
96
97	if (buf_size < 1)
98	goto fail;
99
100	/* TOC byte */
101	i = *ptr++;
102	pkt->code = (i ) & 0x3;
103	pkt->stereo = (i >> 2) & 0x1;
104	pkt->config = (i >> 3) & 0x1F;
105
106	/* code 2 and code 3 packets have at least 1 byte after the TOC */
107	if (pkt->code >= 2 && buf_size < 2)
108	goto fail;
109
110	switch (pkt->code) {
111	case 0:
112	/* 1 frame */
113	pkt->frame_count = 1;
114	pkt->vbr = 0;
115
116	if (self_delimiting) {
117	int len = xiph_lacing_16bit(&ptr, end);
118	if (len < 0 || len > end - ptr)
119	goto fail;
120	end = ptr + len;
121	buf_size = end - buf;
122	}
123
124	frame_bytes = end - ptr;
125	if (frame_bytes > MAX_FRAME_SIZE)
126	goto fail;
127	pkt->frame_offset[0] = ptr - buf;
128	pkt->frame_size[0] = frame_bytes;
129	break;
130	case 1:
131	/* 2 frames, equal size */
132	pkt->frame_count = 2;
133	pkt->vbr = 0;
134
135	if (self_delimiting) {
136	int len = xiph_lacing_16bit(&ptr, end);
137	if (len < 0 || 2 * len > end - ptr)
138	goto fail;
139	end = ptr + 2 * len;
140	buf_size = end - buf;
141	}
142
143	frame_bytes = end - ptr;
144	if (frame_bytes & 1 || frame_bytes >> 1 > MAX_FRAME_SIZE)
145	goto fail;
146	pkt->frame_offset[0] = ptr - buf;
147	pkt->frame_size[0] = frame_bytes >> 1;
148	pkt->frame_offset[1] = pkt->frame_offset[0] + pkt->frame_size[0];
149	pkt->frame_size[1] = frame_bytes >> 1;
150	break;
151	case 2:
152	/* 2 frames, different sizes */
153	pkt->frame_count = 2;
154	pkt->vbr = 1;
155
156	/* read 1st frame size */
157	frame_bytes = xiph_lacing_16bit(&ptr, end);
158	if (frame_bytes < 0)
159	goto fail;
160
161	if (self_delimiting) {
162	int len = xiph_lacing_16bit(&ptr, end);
163	if (len < 0 || len + frame_bytes > end - ptr)
164	goto fail;
165	end = ptr + frame_bytes + len;
166	buf_size = end - buf;
167	}
168
169	pkt->frame_offset[0] = ptr - buf;
170	pkt->frame_size[0] = frame_bytes;
171
172	/* calculate 2nd frame size */
173	frame_bytes = end - ptr - pkt->frame_size[0];
174	if (frame_bytes < 0 || frame_bytes > MAX_FRAME_SIZE)
175	goto fail;
176	pkt->frame_offset[1] = pkt->frame_offset[0] + pkt->frame_size[0];
177	pkt->frame_size[1] = frame_bytes;
178	break;
179	case 3:
180	/* 1 to 48 frames, can be different sizes */
181	i = *ptr++;
182	pkt->frame_count = (i ) & 0x3F;
183	padding = (i >> 6) & 0x01;
184	pkt->vbr = (i >> 7) & 0x01;
185
186	if (pkt->frame_count == 0 || pkt->frame_count > MAX_FRAMES)
187	goto fail;
188
189	/* read padding size */
190	if (padding) {
191	padding = xiph_lacing_full(&ptr, end);
192	if (padding < 0)
193	goto fail;
194	}
195
196	/* read frame sizes */
197	if (pkt->vbr) {
198	/* for VBR, all frames except the final one have their size coded
199	in the bitstream. the last frame size is implicit. */
200	int total_bytes = 0;
201	for (i = 0; i < pkt->frame_count - 1; i++) {
202	frame_bytes = xiph_lacing_16bit(&ptr, end);
203	if (frame_bytes < 0)
204	goto fail;
205	pkt->frame_size[i] = frame_bytes;
206	total_bytes += frame_bytes;
207	}
208
209	if (self_delimiting) {
210	int len = xiph_lacing_16bit(&ptr, end);
211	if (len < 0 || len + total_bytes + padding > end - ptr)
212	goto fail;
213	end = ptr + total_bytes + len + padding;
214	buf_size = end - buf;
215	}
216
217	frame_bytes = end - ptr - padding;
218	if (total_bytes > frame_bytes)
219	goto fail;
220	pkt->frame_offset[0] = ptr - buf;
221	for (i = 1; i < pkt->frame_count; i++)
222	pkt->frame_offset[i] = pkt->frame_offset[i-1] + pkt->frame_size[i-1];
223	pkt->frame_size[pkt->frame_count-1] = frame_bytes - total_bytes;
224	} else {
225	/* for CBR, the remaining packet bytes are divided evenly between
226	the frames */
227	if (self_delimiting) {
228	frame_bytes = xiph_lacing_16bit(&ptr, end);
229	if (frame_bytes < 0 || pkt->frame_count * frame_bytes + padding > end - ptr)
230	goto fail;
231	end = ptr + pkt->frame_count * frame_bytes + padding;
232	buf_size = end - buf;
233	} else {
234	frame_bytes = end - ptr - padding;
235	if (frame_bytes % pkt->frame_count ||
236	frame_bytes / pkt->frame_count > MAX_FRAME_SIZE)
237	goto fail;
238	frame_bytes /= pkt->frame_count;
239	}
240
241	pkt->frame_offset[0] = ptr - buf;
242	pkt->frame_size[0] = frame_bytes;
243	for (i = 1; i < pkt->frame_count; i++) {
244	pkt->frame_offset[i] = pkt->frame_offset[i-1] + pkt->frame_size[i-1];
245	pkt->frame_size[i] = frame_bytes;
246	}
247	}
248	}
249
250	pkt->packet_size = buf_size;
251	pkt->data_size = pkt->packet_size - padding;
252
253	/* total packet duration cannot be larger than 120ms */
254	pkt->frame_duration = opus_frame_duration[pkt->config];
255	if (pkt->frame_duration * pkt->frame_count > MAX_PACKET_DUR)
256	goto fail;
257
258	/* set mode and bandwidth */
259	if (pkt->config < 12) {
260	pkt->mode = OPUS_MODE_SILK;
261	pkt->bandwidth = pkt->config >> 2;
262	} else if (pkt->config < 16) {
263	pkt->mode = OPUS_MODE_HYBRID;
264	pkt->bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND + (pkt->config >= 14);
265	} else {
266	pkt->mode = OPUS_MODE_CELT;
267	pkt->bandwidth = (pkt->config - 16) >> 2;
268	/* skip medium band */
269	if (pkt->bandwidth)
270	pkt->bandwidth++;
271	}
272
273	return 0;
274
275	fail:
276	memset(pkt, 0, sizeof(*pkt));
277	return AVERROR_INVALIDDATA;
278	}
279
280	static int channel_reorder_vorbis(int nb_channels, int channel_idx)
281	{
282	return ff_vorbis_channel_layout_offsets[nb_channels - 1][channel_idx];
283	}
284
285	static int channel_reorder_unknown(int nb_channels, int channel_idx)
286	{
287	return channel_idx;
288	}
289
290	av_cold int ff_opus_parse_extradata(AVCodecContext *avctx,
291	OpusContext *s)
292	{
293	static const uint8_t default_channel_map[2] = { 0, 1 };
294
295	int (*channel_reorder)(int, int) = channel_reorder_unknown;
296
297	const uint8_t *extradata, *channel_map;
298	int extradata_size;
299	int version, channels, map_type, streams, stereo_streams, i, j;
300	uint64_t layout;
301
302	if (!avctx->extradata) {
303	if (avctx->channels > 2) {
304	av_log(avctx, AV_LOG_ERROR,
305	"Multichannel configuration without extradata.\n");
306	return AVERROR(EINVAL);
307	}
308	extradata = opus_default_extradata;
309	extradata_size = sizeof(opus_default_extradata);
310	} else {
311	extradata = avctx->extradata;
312	extradata_size = avctx->extradata_size;
313	}
314
315	if (extradata_size < 19) {
316	av_log(avctx, AV_LOG_ERROR, "Invalid extradata size: %d\n",
317	extradata_size);
318	return AVERROR_INVALIDDATA;
319	}
320
321	version = extradata[8];
322	if (version > 15) {
323	avpriv_request_sample(avctx, "Extradata version %d", version);
324	return AVERROR_PATCHWELCOME;
325	}
326
327	avctx->delay = AV_RL16(extradata + 10);
328
329	channels = avctx->extradata ? extradata[9] : (avctx->channels == 1) ? 1 : 2;
330	if (!channels) {
331	av_log(avctx, AV_LOG_ERROR, "Zero channel count specified in the extradata\n");
332	return AVERROR_INVALIDDATA;
333	}
334
335	s->gain_i = AV_RL16(extradata + 16);
336	if (s->gain_i)
337	s->gain = ff_exp10(s->gain_i / (20.0 * 256));
338
339	map_type = extradata[18];
340	if (!map_type) {
341	if (channels > 2) {
342	av_log(avctx, AV_LOG_ERROR,
343	"Channel mapping 0 is only specified for up to 2 channels\n");
344	return AVERROR_INVALIDDATA;
345	}
346	layout = (channels == 1) ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
347	streams = 1;
348	stereo_streams = channels - 1;
349	channel_map = default_channel_map;
350	} else if (map_type == 1 || map_type == 2 || map_type == 255) {
351	if (extradata_size < 21 + channels) {
352	av_log(avctx, AV_LOG_ERROR, "Invalid extradata size: %d\n",
353	extradata_size);
354	return AVERROR_INVALIDDATA;
355	}
356
357	streams = extradata[19];
358	stereo_streams = extradata[20];
359	if (!streams || stereo_streams > streams ||
360	streams + stereo_streams > 255) {
361	av_log(avctx, AV_LOG_ERROR,
362	"Invalid stream/stereo stream count: %d/%d\n", streams, stereo_streams);
363	return AVERROR_INVALIDDATA;
364	}
365
366	if (map_type == 1) {
367	if (channels > 8) {
368	av_log(avctx, AV_LOG_ERROR,
369	"Channel mapping 1 is only specified for up to 8 channels\n");
370	return AVERROR_INVALIDDATA;
371	}
372	layout = ff_vorbis_channel_layouts[channels - 1];
373	channel_reorder = channel_reorder_vorbis;
374	} else if (map_type == 2) {
375	int ambisonic_order = ff_sqrt(channels) - 1;
376	if (channels != ((ambisonic_order + 1) * (ambisonic_order + 1)) &&
377	channels != ((ambisonic_order + 1) * (ambisonic_order + 1) + 2)) {
378	av_log(avctx, AV_LOG_ERROR,
379	"Channel mapping 2 is only specified for channel counts"
380	" which can be written as (n + 1)^2 or (n + 1)^2 + 2"
381	" for nonnegative integer n\n");
382	return AVERROR_INVALIDDATA;
383	}
384	if (channels > 227) {
385	av_log(avctx, AV_LOG_ERROR, "Too many channels\n");
386	return AVERROR_INVALIDDATA;
387	}
388	layout = 0;
389	} else
390	layout = 0;
391
392	channel_map = extradata + 21;
393	} else {
394	avpriv_request_sample(avctx, "Mapping type %d", map_type);
395	return AVERROR_PATCHWELCOME;
396	}
397
398	s->channel_maps = av_mallocz_array(channels, sizeof(*s->channel_maps));
399	if (!s->channel_maps)
400	return AVERROR(ENOMEM);
401
402	for (i = 0; i < channels; i++) {
403	ChannelMap *map = &s->channel_maps[i];
404	uint8_t idx = channel_map[channel_reorder(channels, i)];
405
406	if (idx == 255) {
407	map->silence = 1;
408	continue;
409	} else if (idx >= streams + stereo_streams) {
410	av_log(avctx, AV_LOG_ERROR,
411	"Invalid channel map for output channel %d: %d\n", i, idx);
412	av_freep(&s->channel_maps);
413	return AVERROR_INVALIDDATA;
414	}
415
416	/* check that we did not see this index yet */
417	map->copy = 0;
418	for (j = 0; j < i; j++)
419	if (channel_map[channel_reorder(channels, j)] == idx) {
420	map->copy = 1;
421	map->copy_idx = j;
422	break;
423	}
424
425	if (idx < 2 * stereo_streams) {
426	map->stream_idx = idx / 2;
427	map->channel_idx = idx & 1;
428	} else {
429	map->stream_idx = idx - stereo_streams;
430	map->channel_idx = 0;
431	}
432	}
433
434	avctx->channels = channels;
435	avctx->channel_layout = layout;
436	s->nb_streams = streams;
437	s->nb_stereo_streams = stereo_streams;
438
439	return 0;
440	}
441