1 /*
2 * RTP parser for DV payload format (RFC 6469)
3 * Copyright (c) 2015 Thomas Volkert <thomas@homer-conferencing.com>
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 #include "libavutil/avstring.h"
23
24 #include "avio_internal.h"
25 #include "rtpdec.h"
26
27 struct PayloadContext {
28 AVIOContext *buf;
29 uint32_t timestamp;
30 int bundled_audio;
31 };
32
dv_close_context(PayloadContext * data)33 static av_cold void dv_close_context(PayloadContext *data)
34 {
35 ffio_free_dyn_buf(&data->buf);
36 }
37
dv_sdp_parse_fmtp_config(AVFormatContext * s,AVStream * stream,PayloadContext * dv_data,const char * attr,const char * value)38 static av_cold int dv_sdp_parse_fmtp_config(AVFormatContext *s,
39 AVStream *stream,
40 PayloadContext *dv_data,
41 const char *attr, const char *value)
42 {
43 /* does the DV stream include audio? */
44 if (!strcmp(attr, "audio") && !strcmp(value, "bundled"))
45 dv_data->bundled_audio = 1;
46
47 /* extract the DV profile */
48 if (!strcmp(attr, "encode")) {
49 /* SD-VCR/525-60 */
50 /* SD-VCR/625-50 */
51 /* HD-VCR/1125-60 */
52 /* HD-VCR/1250-50 */
53 /* SDL-VCR/525-60 */
54 /* SDL-VCR/625-50 */
55 /* 314M-25/525-60 */
56 /* 314M-25/625-50 */
57 /* 314M-50/525-60 */
58 /* 314M-50/625-50 */
59 /* 370M/1080-60i */
60 /* 370M/1080-50i */
61 /* 370M/720-60p */
62 /* 370M/720-50p */
63 /* 306M/525-60 (for backward compatibility) */
64 /* 306M/625-50 (for backward compatibility) */
65 }
66
67 return 0;
68 }
69
dv_parse_sdp_line(AVFormatContext * ctx,int st_index,PayloadContext * dv_data,const char * line)70 static av_cold int dv_parse_sdp_line(AVFormatContext *ctx, int st_index,
71 PayloadContext *dv_data, const char *line)
72 {
73 AVStream *current_stream;
74 const char *sdp_line_ptr = line;
75
76 if (st_index < 0)
77 return 0;
78
79 current_stream = ctx->streams[st_index];
80
81 if (av_strstart(sdp_line_ptr, "fmtp:", &sdp_line_ptr)) {
82 return ff_parse_fmtp(ctx, current_stream, dv_data, sdp_line_ptr,
83 dv_sdp_parse_fmtp_config);
84 }
85
86 return 0;
87 }
88
dv_handle_packet(AVFormatContext * ctx,PayloadContext * rtp_dv_ctx,AVStream * st,AVPacket * pkt,uint32_t * timestamp,const uint8_t * buf,int len,uint16_t seq,int flags)89 static int dv_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_dv_ctx,
90 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
91 const uint8_t *buf, int len, uint16_t seq,
92 int flags)
93 {
94 int res = 0;
95
96 /* drop data of previous packets in case of non-continuous (lossy) packet stream */
97 if (rtp_dv_ctx->buf && rtp_dv_ctx->timestamp != *timestamp) {
98 ffio_free_dyn_buf(&rtp_dv_ctx->buf);
99 }
100
101 /* sanity check for size of input packet: 1 byte payload at least */
102 if (len < 1) {
103 av_log(ctx, AV_LOG_ERROR, "Too short RTP/DV packet, got %d bytes\n", len);
104 return AVERROR_INVALIDDATA;
105 }
106
107 /* start frame buffering with new dynamic buffer */
108 if (!rtp_dv_ctx->buf) {
109 res = avio_open_dyn_buf(&rtp_dv_ctx->buf);
110 if (res < 0)
111 return res;
112 /* update the timestamp in the frame packet with the one from the RTP packet */
113 rtp_dv_ctx->timestamp = *timestamp;
114 }
115
116 /* write the fragment to the dyn. buffer */
117 avio_write(rtp_dv_ctx->buf, buf, len);
118
119 /* RTP marker bit means: last fragment of current frame was received;
120 otherwise, an additional fragment is needed for the current frame */
121 if (!(flags & RTP_FLAG_MARKER))
122 return AVERROR(EAGAIN);
123
124 /* close frame buffering and create resulting A/V packet */
125 res = ff_rtp_finalize_packet(pkt, &rtp_dv_ctx->buf, st->index);
126 if (res < 0)
127 return res;
128
129 return 0;
130 }
131
132 const RTPDynamicProtocolHandler ff_dv_dynamic_handler = {
133 .enc_name = "DV",
134 .codec_type = AVMEDIA_TYPE_VIDEO,
135 .codec_id = AV_CODEC_ID_DVVIDEO,
136 .need_parsing = AVSTREAM_PARSE_FULL,
137 .parse_sdp_a_line = dv_parse_sdp_line,
138 .priv_data_size = sizeof(PayloadContext),
139 .close = dv_close_context,
140 .parse_packet = dv_handle_packet,
141 };
142