Imported Debian version 2.4.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavformat / rtpdec_qdm2.c
CommitLineData
2ba45a60
DM
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
37struct 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 */
77static 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->codec->extradata);
108 if (ff_alloc_extradata(st->codec, 26 + item_len)) {
109 return AVERROR(ENOMEM);
110 }
111 AV_WB32(st->codec->extradata, 12);
112 memcpy(st->codec->extradata + 4, "frma", 4);
113 memcpy(st->codec->extradata + 8, "QDM2", 4);
114 AV_WB32(st->codec->extradata + 12, 6 + item_len);
115 memcpy(st->codec->extradata + 16, "QDCA", 4);
116 memcpy(st->codec->extradata + 20, p + 2, item_len - 2);
117 AV_WB32(st->codec->extradata + 18 + item_len, 8);
118 AV_WB32(st->codec->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 */
152static 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 */
186static 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 assert(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... */
237static 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->codec->codec_id = AV_CODEC_ID_QDM2;
269 }
270 if (st->codec->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
301static PayloadContext *qdm2_extradata_new(void)
302{
303 return av_mallocz(sizeof(PayloadContext));
304}
305
306static void qdm2_extradata_free(PayloadContext *qdm)
307{
308 av_free(qdm);
309}
310
311RTPDynamicProtocolHandler ff_qdm2_dynamic_handler = {
312 .enc_name = "X-QDM",
313 .codec_type = AVMEDIA_TYPE_AUDIO,
314 .codec_id = AV_CODEC_ID_NONE,
315 .alloc = qdm2_extradata_new,
316 .free = qdm2_extradata_free,
317 .parse_packet = qdm2_parse_packet,
318};