blob: 41cc8263dfc9097ae0d4999a9a7ebd000d791f59
1 | /* |
2 | * RTP Depacketization of QCELP/PureVoice, RFC 2658 |
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 "rtpdec_formats.h" |
23 | |
24 | static const uint8_t frame_sizes[] = { |
25 | 1, 4, 8, 17, 35 |
26 | }; |
27 | |
28 | typedef struct InterleavePacket { |
29 | int pos; |
30 | int size; |
31 | /* The largest frame is 35 bytes, only 10 frames are allowed per |
32 | * packet, and we return the first one immediately, so allocate |
33 | * space for 9 frames */ |
34 | uint8_t data[35*9]; |
35 | } InterleavePacket; |
36 | |
37 | struct PayloadContext { |
38 | int interleave_size; |
39 | int interleave_index; |
40 | InterleavePacket group[6]; |
41 | int group_finished; |
42 | |
43 | /* The maximum packet size, 10 frames of 35 bytes each, and one |
44 | * packet header byte. */ |
45 | uint8_t next_data[1 + 35*10]; |
46 | int next_size; |
47 | uint32_t next_timestamp; |
48 | }; |
49 | |
50 | static int return_stored_frame(AVFormatContext *ctx, PayloadContext *data, |
51 | AVStream *st, AVPacket *pkt, uint32_t *timestamp, |
52 | const uint8_t *buf, int len); |
53 | |
54 | static int store_packet(AVFormatContext *ctx, PayloadContext *data, |
55 | AVStream *st, AVPacket *pkt, uint32_t *timestamp, |
56 | const uint8_t *buf, int len) |
57 | { |
58 | int interleave_size, interleave_index; |
59 | int frame_size, ret; |
60 | InterleavePacket* ip; |
61 | |
62 | if (len < 2) |
63 | return AVERROR_INVALIDDATA; |
64 | |
65 | interleave_size = buf[0] >> 3 & 7; |
66 | interleave_index = buf[0] & 7; |
67 | |
68 | if (interleave_size > 5) { |
69 | av_log(ctx, AV_LOG_ERROR, "Invalid interleave size %d\n", |
70 | interleave_size); |
71 | return AVERROR_INVALIDDATA; |
72 | } |
73 | if (interleave_index > interleave_size) { |
74 | av_log(ctx, AV_LOG_ERROR, "Invalid interleave index %d/%d\n", |
75 | interleave_index, interleave_size); |
76 | return AVERROR_INVALIDDATA; |
77 | } |
78 | if (interleave_size != data->interleave_size) { |
79 | int i; |
80 | /* First packet, or changed interleave size */ |
81 | data->interleave_size = interleave_size; |
82 | data->interleave_index = 0; |
83 | for (i = 0; i < 6; i++) |
84 | data->group[i].size = 0; |
85 | } |
86 | |
87 | if (interleave_index < data->interleave_index) { |
88 | /* Wrapped around - missed the last packet of the previous group. */ |
89 | if (data->group_finished) { |
90 | /* No more data in the packets in this interleaving group, just |
91 | * start processing the next one */ |
92 | data->interleave_index = 0; |
93 | } else { |
94 | /* Stash away the current packet, emit everything we have of the |
95 | * previous group. */ |
96 | for (; data->interleave_index <= interleave_size; |
97 | data->interleave_index++) |
98 | data->group[data->interleave_index].size = 0; |
99 | |
100 | if (len > sizeof(data->next_data)) |
101 | return AVERROR_INVALIDDATA; |
102 | memcpy(data->next_data, buf, len); |
103 | data->next_size = len; |
104 | data->next_timestamp = *timestamp; |
105 | *timestamp = RTP_NOTS_VALUE; |
106 | |
107 | data->interleave_index = 0; |
108 | return return_stored_frame(ctx, data, st, pkt, timestamp, buf, len); |
109 | } |
110 | } |
111 | if (interleave_index > data->interleave_index) { |
112 | /* We missed a packet */ |
113 | for (; data->interleave_index < interleave_index; |
114 | data->interleave_index++) |
115 | data->group[data->interleave_index].size = 0; |
116 | } |
117 | data->interleave_index = interleave_index; |
118 | |
119 | if (buf[1] >= FF_ARRAY_ELEMS(frame_sizes)) |
120 | return AVERROR_INVALIDDATA; |
121 | frame_size = frame_sizes[buf[1]]; |
122 | if (1 + frame_size > len) |
123 | return AVERROR_INVALIDDATA; |
124 | |
125 | if (len - 1 - frame_size > sizeof(data->group[0].data)) |
126 | return AVERROR_INVALIDDATA; |
127 | |
128 | if ((ret = av_new_packet(pkt, frame_size)) < 0) |
129 | return ret; |
130 | memcpy(pkt->data, &buf[1], frame_size); |
131 | pkt->stream_index = st->index; |
132 | |
133 | ip = &data->group[data->interleave_index]; |
134 | ip->size = len - 1 - frame_size; |
135 | ip->pos = 0; |
136 | memcpy(ip->data, &buf[1 + frame_size], ip->size); |
137 | /* Each packet must contain the same number of frames according to the |
138 | * RFC. If there's no data left in this packet, there shouldn't be any |
139 | * in any of the other frames in the interleaving group either. */ |
140 | data->group_finished = ip->size == 0; |
141 | |
142 | if (interleave_index == interleave_size) { |
143 | data->interleave_index = 0; |
144 | return !data->group_finished; |
145 | } else { |
146 | data->interleave_index++; |
147 | return 0; |
148 | } |
149 | } |
150 | |
151 | static int return_stored_frame(AVFormatContext *ctx, PayloadContext *data, |
152 | AVStream *st, AVPacket *pkt, uint32_t *timestamp, |
153 | const uint8_t *buf, int len) |
154 | { |
155 | InterleavePacket* ip = &data->group[data->interleave_index]; |
156 | int frame_size, ret; |
157 | |
158 | if (data->group_finished && data->interleave_index == 0) { |
159 | *timestamp = data->next_timestamp; |
160 | ret = store_packet(ctx, data, st, pkt, timestamp, data->next_data, |
161 | data->next_size); |
162 | data->next_size = 0; |
163 | return ret; |
164 | } |
165 | |
166 | if (ip->size == 0) { |
167 | /* No stored data for this interleave block, output an empty packet */ |
168 | if ((ret = av_new_packet(pkt, 1)) < 0) |
169 | return ret; |
170 | pkt->data[0] = 0; // Blank - could also be 14, Erasure |
171 | } else { |
172 | if (ip->pos >= ip->size) |
173 | return AVERROR_INVALIDDATA; |
174 | if (ip->data[ip->pos] >= FF_ARRAY_ELEMS(frame_sizes)) |
175 | return AVERROR_INVALIDDATA; |
176 | frame_size = frame_sizes[ip->data[ip->pos]]; |
177 | if (ip->pos + frame_size > ip->size) |
178 | return AVERROR_INVALIDDATA; |
179 | |
180 | if ((ret = av_new_packet(pkt, frame_size)) < 0) |
181 | return ret; |
182 | memcpy(pkt->data, &ip->data[ip->pos], frame_size); |
183 | |
184 | ip->pos += frame_size; |
185 | data->group_finished = ip->pos >= ip->size; |
186 | } |
187 | pkt->stream_index = st->index; |
188 | |
189 | if (data->interleave_index == data->interleave_size) { |
190 | data->interleave_index = 0; |
191 | if (!data->group_finished) |
192 | return 1; |
193 | else |
194 | return data->next_size > 0; |
195 | } else { |
196 | data->interleave_index++; |
197 | return 1; |
198 | } |
199 | } |
200 | |
201 | static int qcelp_parse_packet(AVFormatContext *ctx, PayloadContext *data, |
202 | AVStream *st, AVPacket *pkt, uint32_t *timestamp, |
203 | const uint8_t *buf, int len, uint16_t seq, |
204 | int flags) |
205 | { |
206 | if (buf) |
207 | return store_packet(ctx, data, st, pkt, timestamp, buf, len); |
208 | else |
209 | return return_stored_frame(ctx, data, st, pkt, timestamp, buf, len); |
210 | } |
211 | |
212 | RTPDynamicProtocolHandler ff_qcelp_dynamic_handler = { |
213 | .enc_name = "x-Purevoice", |
214 | .codec_type = AVMEDIA_TYPE_AUDIO, |
215 | .codec_id = AV_CODEC_ID_QCELP, |
216 | .priv_data_size = sizeof(PayloadContext), |
217 | .static_payload_id = 12, |
218 | .parse_packet = qcelp_parse_packet, |
219 | }; |
220 |