1 /*
2 * RTP/Quicktime support.
3 * Copyright (c) 2009 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 Quicktime-style RTP support
25 * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
26 */
27
28 #include "avformat.h"
29 #include "internal.h"
30 #include "avio_internal.h"
31 #include "rtp.h"
32 #include "rtpdec.h"
33 #include "isom.h"
34 #include "libavcodec/get_bits.h"
35
36 struct PayloadContext {
37 AVPacket *pkt;
38 int bytes_per_frame, remaining;
39 uint32_t timestamp;
40 };
41
qt_rtp_init(AVFormatContext * ctx,int st_index,PayloadContext * qt)42 static av_cold int qt_rtp_init(AVFormatContext *ctx, int st_index,
43 PayloadContext *qt)
44 {
45 qt->pkt = av_packet_alloc();
46 if (!qt->pkt)
47 return AVERROR(ENOMEM);
48
49 return 0;
50 }
51
qt_rtp_parse_packet(AVFormatContext * s,PayloadContext * qt,AVStream * st,AVPacket * pkt,uint32_t * timestamp,const uint8_t * buf,int len,uint16_t seq,int flags)52 static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
53 AVStream *st, AVPacket *pkt,
54 uint32_t *timestamp, const uint8_t *buf,
55 int len, uint16_t seq, int flags)
56 {
57 FFIOContext pb0;
58 AVIOContext *const pb = &pb0.pub;
59 GetBitContext gb;
60 int packing_scheme, has_payload_desc, has_packet_info, alen,
61 has_marker_bit = flags & RTP_FLAG_MARKER,
62 keyframe, ret;
63
64 if (qt->remaining) {
65 int num = qt->pkt->size / qt->bytes_per_frame;
66
67 if ((ret = av_new_packet(pkt, qt->bytes_per_frame)) < 0)
68 return ret;
69 pkt->stream_index = st->index;
70 pkt->flags = qt->pkt->flags;
71 memcpy(pkt->data,
72 &qt->pkt->data[(num - qt->remaining) * qt->bytes_per_frame],
73 qt->bytes_per_frame);
74 if (--qt->remaining == 0) {
75 av_freep(&qt->pkt->data);
76 qt->pkt->size = 0;
77 }
78 return qt->remaining > 0;
79 }
80
81 /**
82 * The RTP payload is described in:
83 * http://developer.apple.com/quicktime/icefloe/dispatch026.html
84 */
85 ret = init_get_bits(&gb, buf, len << 3);
86 if (ret < 0)
87 return ret;
88 ffio_init_context(&pb0, (uint8_t*)buf, len, 0, NULL, NULL, NULL, NULL);
89
90 if (len < 4)
91 return AVERROR_INVALIDDATA;
92
93 skip_bits(&gb, 4); // version
94 if ((packing_scheme = get_bits(&gb, 2)) == 0)
95 return AVERROR_INVALIDDATA;
96 keyframe = get_bits1(&gb);
97 has_payload_desc = get_bits1(&gb);
98 has_packet_info = get_bits1(&gb);
99 skip_bits(&gb, 23); // reserved:7, cache payload info:1, payload ID:15
100
101 if (has_payload_desc) {
102 int data_len, pos, is_start, is_finish;
103 uint32_t tag;
104
105 pos = get_bits_count(&gb) >> 3;
106 if (pos + 12 > len)
107 return AVERROR_INVALIDDATA;
108
109 skip_bits(&gb, 2); // has non-I-frames:1, is sparse:1
110 is_start = get_bits1(&gb);
111 is_finish = get_bits1(&gb);
112 if (!is_start || !is_finish) {
113 avpriv_request_sample(s, "RTP-X-QT with payload description "
114 "split over several packets");
115 return AVERROR_PATCHWELCOME;
116 }
117 skip_bits(&gb, 12); // reserved
118 data_len = get_bits(&gb, 16);
119
120 avio_seek(pb, pos + 4, SEEK_SET);
121 tag = avio_rl32(pb);
122 if ((st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
123 tag != MKTAG('v','i','d','e')) ||
124 (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
125 tag != MKTAG('s','o','u','n')))
126 return AVERROR_INVALIDDATA;
127 avpriv_set_pts_info(st, 32, 1, avio_rb32(pb));
128
129 if (pos + data_len > len)
130 return AVERROR_INVALIDDATA;
131 /* TLVs */
132 while (avio_tell(pb) + 4 < pos + data_len) {
133 int tlv_len = avio_rb16(pb);
134 tag = avio_rl16(pb);
135 if (avio_tell(pb) + tlv_len > pos + data_len)
136 return AVERROR_INVALIDDATA;
137
138 #define MKTAG16(a,b) MKTAG(a,b,0,0)
139 switch (tag) {
140 case MKTAG16('s','d'): {
141 MOVStreamContext *msc;
142 void *priv_data = st->priv_data;
143 int nb_streams = s->nb_streams;
144 MOVContext *mc = av_mallocz(sizeof(*mc));
145 if (!mc)
146 return AVERROR(ENOMEM);
147 mc->fc = s;
148 st->priv_data = msc = av_mallocz(sizeof(MOVStreamContext));
149 if (!msc) {
150 av_free(mc);
151 st->priv_data = priv_data;
152 return AVERROR(ENOMEM);
153 }
154 /* ff_mov_read_stsd_entries updates stream s->nb_streams-1,
155 * so set it temporarily to indicate which stream to update. */
156 s->nb_streams = st->index + 1;
157 ff_mov_read_stsd_entries(mc, pb, 1);
158 qt->bytes_per_frame = msc->bytes_per_frame;
159 av_free(msc);
160 av_free(mc);
161 st->priv_data = priv_data;
162 s->nb_streams = nb_streams;
163 break;
164 }
165 default:
166 avio_skip(pb, tlv_len);
167 break;
168 }
169 }
170
171 /* 32-bit alignment */
172 avio_skip(pb, ((avio_tell(pb) + 3) & ~3) - avio_tell(pb));
173 } else
174 avio_seek(pb, 4, SEEK_SET);
175
176 if (has_packet_info) {
177 avpriv_request_sample(s, "RTP-X-QT with packet-specific info");
178 return AVERROR_PATCHWELCOME;
179 }
180
181 alen = len - avio_tell(pb);
182 if (alen <= 0)
183 return AVERROR_INVALIDDATA;
184
185 switch (packing_scheme) {
186 case 3: /* one data packet spread over 1 or multiple RTP packets */
187 if (qt->pkt->size > 0 && qt->timestamp == *timestamp) {
188 int err;
189 if ((err = av_reallocp(&qt->pkt->data, qt->pkt->size + alen +
190 AV_INPUT_BUFFER_PADDING_SIZE)) < 0) {
191 qt->pkt->size = 0;
192 return err;
193 }
194 } else {
195 av_freep(&qt->pkt->data);
196 av_packet_unref(qt->pkt);
197 qt->pkt->data = av_realloc(NULL, alen + AV_INPUT_BUFFER_PADDING_SIZE);
198 if (!qt->pkt->data)
199 return AVERROR(ENOMEM);
200 qt->pkt->size = 0;
201 qt->timestamp = *timestamp;
202 }
203 memcpy(qt->pkt->data + qt->pkt->size, buf + avio_tell(pb), alen);
204 qt->pkt->size += alen;
205 if (has_marker_bit) {
206 int ret = av_packet_from_data(pkt, qt->pkt->data, qt->pkt->size);
207 if (ret < 0)
208 return ret;
209
210 qt->pkt->size = 0;
211 qt->pkt->data = NULL;
212 pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
213 pkt->stream_index = st->index;
214 memset(pkt->data + pkt->size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
215 return 0;
216 }
217 return AVERROR(EAGAIN);
218
219 case 1: /* constant packet size, multiple packets per RTP packet */
220 if (qt->bytes_per_frame == 0 ||
221 alen % qt->bytes_per_frame != 0)
222 return AVERROR_INVALIDDATA; /* wrongly padded */
223 qt->remaining = (alen / qt->bytes_per_frame) - 1;
224 if ((ret = av_new_packet(pkt, qt->bytes_per_frame)) < 0)
225 return ret;
226 memcpy(pkt->data, buf + avio_tell(pb), qt->bytes_per_frame);
227 pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
228 pkt->stream_index = st->index;
229 if (qt->remaining > 0) {
230 av_freep(&qt->pkt->data);
231 qt->pkt->data = av_realloc(NULL, qt->remaining * qt->bytes_per_frame);
232 if (!qt->pkt->data) {
233 av_packet_unref(pkt);
234 return AVERROR(ENOMEM);
235 }
236 qt->pkt->size = qt->remaining * qt->bytes_per_frame;
237 memcpy(qt->pkt->data,
238 buf + avio_tell(pb) + qt->bytes_per_frame,
239 qt->remaining * qt->bytes_per_frame);
240 qt->pkt->flags = pkt->flags;
241 return 1;
242 }
243 return 0;
244
245 default: /* unimplemented */
246 avpriv_request_sample(NULL, "RTP-X-QT with packing scheme 2");
247 return AVERROR_PATCHWELCOME;
248 }
249 }
250
qt_rtp_close(PayloadContext * qt)251 static void qt_rtp_close(PayloadContext *qt)
252 {
253 av_freep(&qt->pkt->data);
254 av_packet_free(&qt->pkt);
255 }
256
257 #define RTP_QT_HANDLER(m, n, s, t) \
258 const RTPDynamicProtocolHandler ff_ ## m ## _rtp_ ## n ## _handler = { \
259 .enc_name = s, \
260 .codec_type = t, \
261 .codec_id = AV_CODEC_ID_NONE, \
262 .priv_data_size = sizeof(PayloadContext), \
263 .init = qt_rtp_init, \
264 .close = qt_rtp_close, \
265 .parse_packet = qt_rtp_parse_packet, \
266 }
267
268 RTP_QT_HANDLER(qt, vid, "X-QT", AVMEDIA_TYPE_VIDEO);
269 RTP_QT_HANDLER(qt, aud, "X-QT", AVMEDIA_TYPE_AUDIO);
270 RTP_QT_HANDLER(quicktime, vid, "X-QUICKTIME", AVMEDIA_TYPE_VIDEO);
271 RTP_QT_HANDLER(quicktime, aud, "X-QUICKTIME", AVMEDIA_TYPE_AUDIO);
272