1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/*
* RTP parser for AC3 payload format (RFC 4184)
* Copyright (c) 2015 Gilles Chanteperdrix <gch@xenomai.org>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "avio_internal.h"
#include "rtpdec_formats.h"
#define RTP_AC3_PAYLOAD_HEADER_SIZE 2
struct PayloadContext {
unsigned nr_frames;
unsigned last_frame;
uint32_t timestamp;
AVIOContext *fragment;
};
static void ac3_close_context(PayloadContext *data)
{
ffio_free_dyn_buf(&data->fragment);
}
static int ac3_handle_packet(AVFormatContext *ctx, PayloadContext *data,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, uint16_t seq,
int flags)
{
unsigned frame_type;
unsigned nr_frames;
int err;
if (len < RTP_AC3_PAYLOAD_HEADER_SIZE + 1) {
av_log(ctx, AV_LOG_ERROR, "Invalid %d bytes packet\n", len);
return AVERROR_INVALIDDATA;
}
frame_type = buf[0] & 0x3;
nr_frames = buf[1];
buf += RTP_AC3_PAYLOAD_HEADER_SIZE;
len -= RTP_AC3_PAYLOAD_HEADER_SIZE;
switch (frame_type) {
case 0: /* One or more complete frames */
if (!nr_frames) {
av_log(ctx, AV_LOG_ERROR, "Invalid AC3 packet data\n");
return AVERROR_INVALIDDATA;
}
if (av_new_packet(pkt, len)) {
av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
return AVERROR(ENOMEM);
}
pkt->stream_index = st->index;
memcpy(pkt->data, buf, len);
return 0;
case 1:
case 2: /* First fragment */
ffio_free_dyn_buf(&data->fragment);
data->last_frame = 1;
data->nr_frames = nr_frames;
err = avio_open_dyn_buf(&data->fragment);
if (err < 0)
return err;
avio_write(data->fragment, buf, len);
data->timestamp = *timestamp;
return AVERROR(EAGAIN);
case 3: /* Fragment other than first */
if (!data->fragment) {
av_log(ctx, AV_LOG_WARNING,
"Received packet without a start fragment; dropping.\n");
return AVERROR(EAGAIN);
}
if (nr_frames != data->nr_frames ||
data->timestamp != *timestamp) {
ffio_free_dyn_buf(&data->fragment);
av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n");
return AVERROR_INVALIDDATA;
}
avio_write(data->fragment, buf, len);
data->last_frame++;
}
if (!(flags & RTP_FLAG_MARKER))
return AVERROR(EAGAIN);
if (data->last_frame != data->nr_frames) {
ffio_free_dyn_buf(&data->fragment);
av_log(ctx, AV_LOG_ERROR, "Missed %d packets\n",
data->nr_frames - data->last_frame);
return AVERROR_INVALIDDATA;
}
err = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
if (err < 0) {
av_log(ctx, AV_LOG_ERROR,
"Error occurred when getting fragment buffer.\n");
return err;
}
return 0;
}
const RTPDynamicProtocolHandler ff_ac3_dynamic_handler = {
.enc_name = "ac3",
.codec_type = AVMEDIA_TYPE_AUDIO,
.codec_id = AV_CODEC_ID_AC3,
.need_parsing = AVSTREAM_PARSE_FULL,
.priv_data_size = sizeof(PayloadContext),
.close = ac3_close_context,
.parse_packet = ac3_handle_packet,
};
|
