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