blob: 1f4fd5aace5e60a62dce91ddb8b204d4acd18c1a
1 | /* |
2 | * QDesign Music 2 (QDM2) payload for RTP |
3 | * Copyright (c) 2010 Ronald S. Bultje |
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 | * @brief RTP support for the QDM2 payload (todo: wiki) |
25 | * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net> |
26 | */ |
27 | |
28 | #include <string.h> |
29 | #include "libavutil/avassert.h" |
30 | #include "libavutil/intreadwrite.h" |
31 | #include "libavcodec/avcodec.h" |
32 | #include "internal.h" |
33 | #include "rtp.h" |
34 | #include "rtpdec.h" |
35 | #include "rtpdec_formats.h" |
36 | |
37 | struct PayloadContext { |
38 | /** values read from the config header, used as packet headers */ |
39 | //@{ |
40 | int block_type; ///< superblock type, value 2 .. 8 |
41 | int block_size; ///< from extradata, used as pkt length |
42 | int subpkts_per_block; ///< max. nr. of subpackets to add per output buffer |
43 | //@} |
44 | |
45 | /** Temporary storage for superblock restoring, per packet ID (0x80 total) */ |
46 | //@{ |
47 | uint16_t len[0x80]; ///< how much the temporary buffer is filled |
48 | uint8_t buf[0x80][0x800]; ///< the temporary storage buffer |
49 | |
50 | unsigned int cache; ///< number of data packets that we have cached right now |
51 | unsigned int n_pkts; ///< number of RTP packets received since last packet output / config |
52 | uint32_t timestamp; ///< timestamp of next-to-be-returned packet |
53 | //@} |
54 | }; |
55 | |
56 | /** |
57 | * Parse configuration (basically the codec-specific extradata) from |
58 | * an RTP config subpacket (starts with 0xff). |
59 | * |
60 | * Layout of the config subpacket (in bytes): |
61 | * 1: 0xFF <- config ID |
62 | * then an array { |
63 | * 1: size <- of the current item |
64 | * 1: item type <- 0 .. 4 |
65 | * size-2: data <- data depends on the item type |
66 | * } |
67 | * |
68 | * Item 0 implies the end of the config subpacket, and has no data. |
69 | * Item 1 implies a stream configuration without extradata. |
70 | * Item 2 max. nr. of subpackets per superblock |
71 | * Item 3 superblock type for the stream |
72 | * Item 4 implies a stream configuration with extradata (size >= 0x1c). |
73 | * |
74 | * @return <0 on error, otherwise the number of bytes parsed from the |
75 | * input buffer. |
76 | */ |
77 | static int qdm2_parse_config(PayloadContext *qdm, AVStream *st, |
78 | const uint8_t *buf, const uint8_t *end) |
79 | { |
80 | const uint8_t *p = buf; |
81 | |
82 | while (end - p >= 2) { |
83 | unsigned int item_len = p[0], config_item = p[1]; |
84 | |
85 | if (item_len < 2 || end - p < item_len || config_item > 4) |
86 | return AVERROR_INVALIDDATA; |
87 | |
88 | switch (config_item) { |
89 | case 0: /* end of config block */ |
90 | return p - buf + item_len; |
91 | case 1: /* stream without extradata */ |
92 | /* FIXME: set default qdm->block_size */ |
93 | break; |
94 | case 2: /**< subpackets per block */ |
95 | if (item_len < 3) |
96 | return AVERROR_INVALIDDATA; |
97 | qdm->subpkts_per_block = p[2]; |
98 | break; |
99 | case 3: /* superblock type */ |
100 | if (item_len < 4) |
101 | return AVERROR_INVALIDDATA; |
102 | qdm->block_type = AV_RB16(p + 2); |
103 | break; |
104 | case 4: /* stream with extradata */ |
105 | if (item_len < 30) |
106 | return AVERROR_INVALIDDATA; |
107 | av_freep(&st->codecpar->extradata); |
108 | if (ff_alloc_extradata(st->codecpar, 26 + item_len)) { |
109 | return AVERROR(ENOMEM); |
110 | } |
111 | AV_WB32(st->codecpar->extradata, 12); |
112 | memcpy(st->codecpar->extradata + 4, "frma", 4); |
113 | memcpy(st->codecpar->extradata + 8, "QDM2", 4); |
114 | AV_WB32(st->codecpar->extradata + 12, 6 + item_len); |
115 | memcpy(st->codecpar->extradata + 16, "QDCA", 4); |
116 | memcpy(st->codecpar->extradata + 20, p + 2, item_len - 2); |
117 | AV_WB32(st->codecpar->extradata + 18 + item_len, 8); |
118 | AV_WB32(st->codecpar->extradata + 22 + item_len, 0); |
119 | |
120 | qdm->block_size = AV_RB32(p + 26); |
121 | break; |
122 | } |
123 | |
124 | p += item_len; |
125 | } |
126 | |
127 | return AVERROR(EAGAIN); /* not enough data */ |
128 | } |
129 | |
130 | /** |
131 | * Parse a single subpacket. We store this subpacket in an intermediate |
132 | * buffer (position depends on the ID (byte[0]). When called, at least |
133 | * 4 bytes are available for reading (see qdm2_parse_packet()). |
134 | * |
135 | * Layout of a single subpacket (RTP packets commonly contain multiple |
136 | * such subpackets) - length in bytes: |
137 | * 1: ordering ID <- 0 .. 0x7F |
138 | * 1: subpacket type <- 0 .. 0x7F; value & 0x80 means subpacket length = 2 bytes, else 1 byte |
139 | * 1/2: subpacket length <- length of the data following the flags/length fields |
140 | * if (subpacket type & 0x7F) == 0x7F |
141 | * 1: subpacket type, higher bits |
142 | * size: subpacket data |
143 | * |
144 | * The subpackets come in randomly, and should be encapsulated into 1 |
145 | * or more superblocks (containing qdm->subpkts_per_block subpackets |
146 | * each) per RTP packet, in order of ascending "ordering ID", see |
147 | * qdm2_restore_block(). |
148 | * |
149 | * @return <0 on error, otherwise the number of bytes parsed from the |
150 | * input buffer. |
151 | */ |
152 | static int qdm2_parse_subpacket(PayloadContext *qdm, AVStream *st, |
153 | const uint8_t *buf, const uint8_t *end) |
154 | { |
155 | const uint8_t *p = buf; |
156 | unsigned int id, len, type, to_copy; |
157 | |
158 | /* parse header so we know the size of the header/data */ |
159 | id = *p++; |
160 | type = *p++; |
161 | if (type & 0x80) { |
162 | len = AV_RB16(p); |
163 | p += 2; |
164 | type &= 0x7F; |
165 | } else |
166 | len = *p++; |
167 | |
168 | if (end - p < len + (type == 0x7F) || id >= 0x80) |
169 | return AVERROR_INVALIDDATA; |
170 | if (type == 0x7F) |
171 | type |= *p++ << 8; |
172 | |
173 | /* copy data into a temporary buffer */ |
174 | to_copy = FFMIN(len + (p - &buf[1]), 0x800 - qdm->len[id]); |
175 | memcpy(&qdm->buf[id][qdm->len[id]], buf + 1, to_copy); |
176 | qdm->len[id] += to_copy; |
177 | |
178 | return p + len - buf; |
179 | } |
180 | |
181 | /** |
182 | * Add a superblock header around a set of subpackets. |
183 | * |
184 | * @return <0 on error, else 0. |
185 | */ |
186 | static int qdm2_restore_block(PayloadContext *qdm, AVStream *st, AVPacket *pkt) |
187 | { |
188 | int to_copy, n, res, include_csum; |
189 | uint8_t *p, *csum_pos = NULL; |
190 | |
191 | /* create packet to hold subpkts into a superblock */ |
192 | av_assert0(qdm->cache > 0); |
193 | for (n = 0; n < 0x80; n++) |
194 | if (qdm->len[n] > 0) |
195 | break; |
196 | av_assert0(n < 0x80); |
197 | |
198 | if ((res = av_new_packet(pkt, qdm->block_size)) < 0) |
199 | return res; |
200 | memset(pkt->data, 0, pkt->size); |
201 | pkt->stream_index = st->index; |
202 | p = pkt->data; |
203 | |
204 | /* superblock header */ |
205 | if (qdm->len[n] > 0xff) { |
206 | *p++ = qdm->block_type | 0x80; |
207 | AV_WB16(p, qdm->len[n]); |
208 | p += 2; |
209 | } else { |
210 | *p++ = qdm->block_type; |
211 | *p++ = qdm->len[n]; |
212 | } |
213 | if ((include_csum = (qdm->block_type == 2 || qdm->block_type == 4))) { |
214 | csum_pos = p; |
215 | p += 2; |
216 | } |
217 | |
218 | /* subpacket data */ |
219 | to_copy = FFMIN(qdm->len[n], pkt->size - (p - pkt->data)); |
220 | memcpy(p, qdm->buf[n], to_copy); |
221 | qdm->len[n] = 0; |
222 | |
223 | /* checksum header */ |
224 | if (include_csum) { |
225 | unsigned int total = 0; |
226 | uint8_t *q; |
227 | |
228 | for (q = pkt->data; q < &pkt->data[qdm->block_size]; q++) |
229 | total += *q; |
230 | AV_WB16(csum_pos, (uint16_t) total); |
231 | } |
232 | |
233 | return 0; |
234 | } |
235 | |
236 | /** return 0 on packet, no more left, 1 on packet, -1 on partial packet... */ |
237 | static int qdm2_parse_packet(AVFormatContext *s, PayloadContext *qdm, |
238 | AVStream *st, AVPacket *pkt, |
239 | uint32_t *timestamp, |
240 | const uint8_t *buf, int len, uint16_t seq, |
241 | int flags) |
242 | { |
243 | int res = AVERROR_INVALIDDATA, n; |
244 | const uint8_t *end = buf + len, *p = buf; |
245 | |
246 | if (len > 0) { |
247 | if (len < 2) |
248 | return AVERROR_INVALIDDATA; |
249 | |
250 | /* configuration block */ |
251 | if (*p == 0xff) { |
252 | if (qdm->n_pkts > 0) { |
253 | av_log(s, AV_LOG_WARNING, |
254 | "Out of sequence config - dropping queue\n"); |
255 | qdm->n_pkts = 0; |
256 | memset(qdm->len, 0, sizeof(qdm->len)); |
257 | } |
258 | |
259 | if ((res = qdm2_parse_config(qdm, st, ++p, end)) < 0) |
260 | return res; |
261 | p += res; |
262 | |
263 | /* We set codec_id to AV_CODEC_ID_NONE initially to |
264 | * delay decoder initialization since extradata is |
265 | * carried within the RTP stream, not SDP. Here, |
266 | * by setting codec_id to AV_CODEC_ID_QDM2, we are signalling |
267 | * to the decoder that it is OK to initialize. */ |
268 | st->codecpar->codec_id = AV_CODEC_ID_QDM2; |
269 | } |
270 | if (st->codecpar->codec_id == AV_CODEC_ID_NONE) |
271 | return AVERROR(EAGAIN); |
272 | |
273 | /* subpackets */ |
274 | while (end - p >= 4) { |
275 | if ((res = qdm2_parse_subpacket(qdm, st, p, end)) < 0) |
276 | return res; |
277 | p += res; |
278 | } |
279 | |
280 | qdm->timestamp = *timestamp; |
281 | if (++qdm->n_pkts < qdm->subpkts_per_block) |
282 | return AVERROR(EAGAIN); |
283 | qdm->cache = 0; |
284 | for (n = 0; n < 0x80; n++) |
285 | if (qdm->len[n] > 0) |
286 | qdm->cache++; |
287 | } |
288 | |
289 | /* output the subpackets into freshly created superblock structures */ |
290 | if (!qdm->cache || (res = qdm2_restore_block(qdm, st, pkt)) < 0) |
291 | return res; |
292 | if (--qdm->cache == 0) |
293 | qdm->n_pkts = 0; |
294 | |
295 | *timestamp = qdm->timestamp; |
296 | qdm->timestamp = RTP_NOTS_VALUE; |
297 | |
298 | return (qdm->cache > 0) ? 1 : 0; |
299 | } |
300 | |
301 | RTPDynamicProtocolHandler ff_qdm2_dynamic_handler = { |
302 | .enc_name = "X-QDM", |
303 | .codec_type = AVMEDIA_TYPE_AUDIO, |
304 | .codec_id = AV_CODEC_ID_NONE, |
305 | .priv_data_size = sizeof(PayloadContext), |
306 | .parse_packet = qdm2_parse_packet, |
307 | }; |
308 |