Commit | Line | Data |
---|---|---|
2ba45a60 DM |
1 | /* |
2 | * RTP AMR Depacketizer, RFC 3267 | |
3 | * Copyright (c) 2010 Martin Storsjo | |
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/channel_layout.h" | |
23 | #include "avformat.h" | |
24 | #include "rtpdec_formats.h" | |
25 | #include "libavutil/avstring.h" | |
26 | ||
27 | static const uint8_t frame_sizes_nb[16] = { | |
28 | 12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0 | |
29 | }; | |
30 | static const uint8_t frame_sizes_wb[16] = { | |
31 | 17, 23, 32, 36, 40, 46, 50, 58, 60, 5, 5, 0, 0, 0, 0, 0 | |
32 | }; | |
33 | ||
34 | struct PayloadContext { | |
35 | int octet_align; | |
36 | int crc; | |
37 | int interleaving; | |
38 | int channels; | |
39 | }; | |
40 | ||
41 | static PayloadContext *amr_new_context(void) | |
42 | { | |
43 | PayloadContext *data = av_mallocz(sizeof(PayloadContext)); | |
44 | if(!data) return data; | |
45 | data->channels = 1; | |
46 | return data; | |
47 | } | |
48 | ||
49 | static void amr_free_context(PayloadContext *data) | |
50 | { | |
51 | av_free(data); | |
52 | } | |
53 | ||
54 | static int amr_handle_packet(AVFormatContext *ctx, PayloadContext *data, | |
55 | AVStream *st, AVPacket *pkt, uint32_t *timestamp, | |
56 | const uint8_t *buf, int len, uint16_t seq, | |
57 | int flags) | |
58 | { | |
59 | const uint8_t *frame_sizes = NULL; | |
60 | int frames; | |
61 | int i; | |
62 | const uint8_t *speech_data; | |
63 | uint8_t *ptr; | |
64 | ||
65 | if (st->codec->codec_id == AV_CODEC_ID_AMR_NB) { | |
66 | frame_sizes = frame_sizes_nb; | |
67 | } else if (st->codec->codec_id == AV_CODEC_ID_AMR_WB) { | |
68 | frame_sizes = frame_sizes_wb; | |
69 | } else { | |
70 | av_log(ctx, AV_LOG_ERROR, "Bad codec ID\n"); | |
71 | return AVERROR_INVALIDDATA; | |
72 | } | |
73 | ||
74 | if (st->codec->channels != 1) { | |
75 | av_log(ctx, AV_LOG_ERROR, "Only mono AMR is supported\n"); | |
76 | return AVERROR_INVALIDDATA; | |
77 | } | |
78 | st->codec->channel_layout = AV_CH_LAYOUT_MONO; | |
79 | ||
80 | /* The AMR RTP packet consists of one header byte, followed | |
81 | * by one TOC byte for each AMR frame in the packet, followed | |
82 | * by the speech data for all the AMR frames. | |
83 | * | |
84 | * The header byte contains only a codec mode request, for | |
85 | * requesting what kind of AMR data the sender wants to | |
86 | * receive. Not used at the moment. | |
87 | */ | |
88 | ||
89 | /* Count the number of frames in the packet. The highest bit | |
90 | * is set in a TOC byte if there are more frames following. | |
91 | */ | |
92 | for (frames = 1; frames < len && (buf[frames] & 0x80); frames++) ; | |
93 | ||
94 | if (1 + frames >= len) { | |
95 | /* We hit the end of the packet while counting frames. */ | |
96 | av_log(ctx, AV_LOG_ERROR, "No speech data found\n"); | |
97 | return AVERROR_INVALIDDATA; | |
98 | } | |
99 | ||
100 | speech_data = buf + 1 + frames; | |
101 | ||
102 | /* Everything except the codec mode request byte should be output. */ | |
103 | if (av_new_packet(pkt, len - 1)) { | |
104 | av_log(ctx, AV_LOG_ERROR, "Out of memory\n"); | |
105 | return AVERROR(ENOMEM); | |
106 | } | |
107 | pkt->stream_index = st->index; | |
108 | ptr = pkt->data; | |
109 | ||
110 | for (i = 0; i < frames; i++) { | |
111 | uint8_t toc = buf[1 + i]; | |
112 | int frame_size = frame_sizes[(toc >> 3) & 0x0f]; | |
113 | ||
114 | if (speech_data + frame_size > buf + len) { | |
115 | /* Too little speech data */ | |
116 | av_log(ctx, AV_LOG_WARNING, "Too little speech data in the RTP packet\n"); | |
117 | /* Set the unwritten part of the packet to zero. */ | |
118 | memset(ptr, 0, pkt->data + pkt->size - ptr); | |
119 | pkt->size = ptr - pkt->data; | |
120 | return 0; | |
121 | } | |
122 | ||
123 | /* Extract the AMR frame mode from the TOC byte */ | |
124 | *ptr++ = toc & 0x7C; | |
125 | ||
126 | /* Copy the speech data */ | |
127 | memcpy(ptr, speech_data, frame_size); | |
128 | speech_data += frame_size; | |
129 | ptr += frame_size; | |
130 | } | |
131 | ||
132 | if (speech_data < buf + len) { | |
133 | av_log(ctx, AV_LOG_WARNING, "Too much speech data in the RTP packet?\n"); | |
134 | /* Set the unwritten part of the packet to zero. */ | |
135 | memset(ptr, 0, pkt->data + pkt->size - ptr); | |
136 | pkt->size = ptr - pkt->data; | |
137 | } | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static int amr_parse_fmtp(AVFormatContext *s, | |
143 | AVStream *stream, PayloadContext *data, | |
144 | char *attr, char *value) | |
145 | { | |
146 | /* Some AMR SDP configurations contain "octet-align", without | |
147 | * the trailing =1. Therefore, if the value is empty, | |
148 | * interpret it as "1". | |
149 | */ | |
150 | if (!strcmp(value, "")) { | |
151 | av_log(s, AV_LOG_WARNING, "AMR fmtp attribute %s had " | |
152 | "nonstandard empty value\n", attr); | |
153 | strcpy(value, "1"); | |
154 | } | |
155 | if (!strcmp(attr, "octet-align")) | |
156 | data->octet_align = atoi(value); | |
157 | else if (!strcmp(attr, "crc")) | |
158 | data->crc = atoi(value); | |
159 | else if (!strcmp(attr, "interleaving")) | |
160 | data->interleaving = atoi(value); | |
161 | else if (!strcmp(attr, "channels")) | |
162 | data->channels = atoi(value); | |
163 | return 0; | |
164 | } | |
165 | ||
166 | static int amr_parse_sdp_line(AVFormatContext *s, int st_index, | |
167 | PayloadContext *data, const char *line) | |
168 | { | |
169 | const char *p; | |
170 | int ret; | |
171 | ||
172 | if (st_index < 0) | |
173 | return 0; | |
174 | ||
175 | /* Parse an fmtp line this one: | |
176 | * a=fmtp:97 octet-align=1; interleaving=0 | |
177 | * That is, a normal fmtp: line followed by semicolon & space | |
178 | * separated key/value pairs. | |
179 | */ | |
180 | if (av_strstart(line, "fmtp:", &p)) { | |
181 | ret = ff_parse_fmtp(s, s->streams[st_index], data, p, amr_parse_fmtp); | |
182 | if (!data->octet_align || data->crc || | |
183 | data->interleaving || data->channels != 1) { | |
184 | av_log(s, AV_LOG_ERROR, "Unsupported RTP/AMR configuration!\n"); | |
185 | return -1; | |
186 | } | |
187 | return ret; | |
188 | } | |
189 | return 0; | |
190 | } | |
191 | ||
192 | RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler = { | |
193 | .enc_name = "AMR", | |
194 | .codec_type = AVMEDIA_TYPE_AUDIO, | |
195 | .codec_id = AV_CODEC_ID_AMR_NB, | |
196 | .parse_sdp_a_line = amr_parse_sdp_line, | |
197 | .alloc = amr_new_context, | |
198 | .free = amr_free_context, | |
199 | .parse_packet = amr_handle_packet, | |
200 | }; | |
201 | ||
202 | RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler = { | |
203 | .enc_name = "AMR-WB", | |
204 | .codec_type = AVMEDIA_TYPE_AUDIO, | |
205 | .codec_id = AV_CODEC_ID_AMR_WB, | |
206 | .parse_sdp_a_line = amr_parse_sdp_line, | |
207 | .alloc = amr_new_context, | |
208 | .free = amr_free_context, | |
209 | .parse_packet = amr_handle_packet, | |
210 | }; |