2 * RTP/Quicktime support.
3 * Copyright (c) 2009 Ronald S. Bultje
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * @brief Quicktime-style RTP support
25 * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
28 #include "libavcodec/bitstream.h"
32 #include "avio_internal.h"
37 struct PayloadContext {
39 int bytes_per_frame, remaining;
43 static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt,
44 AVStream *st, AVPacket *pkt,
45 uint32_t *timestamp, const uint8_t *buf,
46 int len, uint16_t seq, int flags)
50 int packing_scheme, has_payload_desc, has_packet_info, alen,
51 has_marker_bit = flags & RTP_FLAG_MARKER,
55 int num = qt->pkt.size / qt->bytes_per_frame;
57 if (av_new_packet(pkt, qt->bytes_per_frame))
58 return AVERROR(ENOMEM);
59 pkt->stream_index = st->index;
60 pkt->flags = qt->pkt.flags;
62 &qt->pkt.data[(num - qt->remaining) * qt->bytes_per_frame],
64 if (--qt->remaining == 0) {
65 av_freep(&qt->pkt.data);
68 return qt->remaining > 0;
72 * The RTP payload is described in:
73 * http://developer.apple.com/quicktime/icefloe/dispatch026.html
75 bitstream_init(&bc, buf, len << 3);
76 ffio_init_context(&pb, buf, len, 0, NULL, NULL, NULL, NULL);
79 return AVERROR_INVALIDDATA;
81 bitstream_skip(&bc, 4); // version
82 if ((packing_scheme = bitstream_read(&bc, 2)) == 0)
83 return AVERROR_INVALIDDATA;
84 keyframe = bitstream_read_bit(&bc);
85 has_payload_desc = bitstream_read_bit(&bc);
86 has_packet_info = bitstream_read_bit(&bc);
87 bitstream_skip(&bc, 23); // reserved:7, cache payload info:1, payload ID:15
89 if (has_payload_desc) {
90 int data_len, pos, is_start, is_finish;
93 pos = bitstream_tell(&bc) >> 3;
95 return AVERROR_INVALIDDATA;
97 bitstream_skip(&bc, 2); // has non-I-frames:1, is sparse:1
98 is_start = bitstream_read_bit(&bc);
99 is_finish = bitstream_read_bit(&bc);
100 if (!is_start || !is_finish) {
101 avpriv_request_sample(s, "RTP-X-QT with payload description "
102 "split over several packets");
103 return AVERROR_PATCHWELCOME;
105 bitstream_skip(&bc, 12); // reserved
106 data_len = bitstream_read(&bc, 16);
108 avio_seek(&pb, pos + 4, SEEK_SET);
109 tag = avio_rl32(&pb);
110 if ((st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
111 tag != MKTAG('v','i','d','e')) ||
112 (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
113 tag != MKTAG('s','o','u','n')))
114 return AVERROR_INVALIDDATA;
115 avpriv_set_pts_info(st, 32, 1, avio_rb32(&pb));
117 if (pos + data_len > len)
118 return AVERROR_INVALIDDATA;
120 while (avio_tell(&pb) + 4 < pos + data_len) {
121 int tlv_len = avio_rb16(&pb);
122 tag = avio_rl16(&pb);
123 if (avio_tell(&pb) + tlv_len > pos + data_len)
124 return AVERROR_INVALIDDATA;
126 #define MKTAG16(a,b) MKTAG(a,b,0,0)
128 case MKTAG16('s','d'): {
129 MOVStreamContext *msc;
130 void *priv_data = st->priv_data;
131 int nb_streams = s->nb_streams;
132 MOVContext *mc = av_mallocz(sizeof(*mc));
134 return AVERROR(ENOMEM);
136 st->priv_data = msc = av_mallocz(sizeof(MOVStreamContext));
139 st->priv_data = priv_data;
140 return AVERROR(ENOMEM);
142 /* ff_mov_read_stsd_entries updates stream s->nb_streams-1,
143 * so set it temporarily to indicate which stream to update. */
144 s->nb_streams = st->index + 1;
145 ff_mov_read_stsd_entries(mc, &pb, 1);
146 qt->bytes_per_frame = msc->bytes_per_frame;
149 st->priv_data = priv_data;
150 s->nb_streams = nb_streams;
154 avio_skip(&pb, tlv_len);
159 /* 32-bit alignment */
160 avio_skip(&pb, ((avio_tell(&pb) + 3) & ~3) - avio_tell(&pb));
162 avio_seek(&pb, 4, SEEK_SET);
164 if (has_packet_info) {
165 avpriv_request_sample(s, "RTP-X-QT with packet-specific info");
166 return AVERROR_PATCHWELCOME;
169 alen = len - avio_tell(&pb);
171 return AVERROR_INVALIDDATA;
173 switch (packing_scheme) {
174 case 3: /* one data packet spread over 1 or multiple RTP packets */
175 if (qt->pkt.size > 0 && qt->timestamp == *timestamp) {
177 if ((err = av_reallocp(&qt->pkt.data, qt->pkt.size + alen +
178 AV_INPUT_BUFFER_PADDING_SIZE)) < 0) {
183 av_freep(&qt->pkt.data);
184 av_init_packet(&qt->pkt);
185 qt->pkt.data = av_realloc(NULL, alen + AV_INPUT_BUFFER_PADDING_SIZE);
187 return AVERROR(ENOMEM);
189 qt->timestamp = *timestamp;
191 memcpy(qt->pkt.data + qt->pkt.size, buf + avio_tell(&pb), alen);
192 qt->pkt.size += alen;
193 if (has_marker_bit) {
194 int ret = av_packet_from_data(pkt, qt->pkt.data, qt->pkt.size);
200 pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
201 pkt->stream_index = st->index;
202 memset(pkt->data + pkt->size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
205 return AVERROR(EAGAIN);
207 case 1: /* constant packet size, multiple packets per RTP packet */
208 if (qt->bytes_per_frame == 0 ||
209 alen % qt->bytes_per_frame != 0)
210 return AVERROR_INVALIDDATA; /* wrongly padded */
211 qt->remaining = (alen / qt->bytes_per_frame) - 1;
212 if (av_new_packet(pkt, qt->bytes_per_frame))
213 return AVERROR(ENOMEM);
214 memcpy(pkt->data, buf + avio_tell(&pb), qt->bytes_per_frame);
215 pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
216 pkt->stream_index = st->index;
217 if (qt->remaining > 0) {
218 av_freep(&qt->pkt.data);
219 qt->pkt.data = av_realloc(NULL, qt->remaining * qt->bytes_per_frame);
221 av_packet_unref(pkt);
222 return AVERROR(ENOMEM);
224 qt->pkt.size = qt->remaining * qt->bytes_per_frame;
226 buf + avio_tell(&pb) + qt->bytes_per_frame,
227 qt->remaining * qt->bytes_per_frame);
228 qt->pkt.flags = pkt->flags;
233 default: /* unimplemented */
234 avpriv_request_sample(NULL, "RTP-X-QT with packing scheme 2");
235 return AVERROR_PATCHWELCOME;
239 static void qt_rtp_close(PayloadContext *qt)
241 av_freep(&qt->pkt.data);
244 #define RTP_QT_HANDLER(m, n, s, t) \
245 RTPDynamicProtocolHandler ff_ ## m ## _rtp_ ## n ## _handler = { \
248 .codec_id = AV_CODEC_ID_NONE, \
249 .priv_data_size = sizeof(PayloadContext), \
250 .close = qt_rtp_close, \
251 .parse_packet = qt_rtp_parse_packet, \
254 RTP_QT_HANDLER(qt, vid, "X-QT", AVMEDIA_TYPE_VIDEO);
255 RTP_QT_HANDLER(qt, aud, "X-QT", AVMEDIA_TYPE_AUDIO);
256 RTP_QT_HANDLER(quicktime, vid, "X-QUICKTIME", AVMEDIA_TYPE_VIDEO);
257 RTP_QT_HANDLER(quicktime, aud, "X-QUICKTIME", AVMEDIA_TYPE_AUDIO);