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8e3fe3d8 | 1 | /* |
2 | * This file is part of DisOrder. | |
3 | * Copyright (C) 2007 Richard Kettlewell | |
4 | * | |
e7eb3a27 | 5 | * This program is free software: you can redistribute it and/or modify |
8e3fe3d8 | 6 | * it under the terms of the GNU General Public License as published by |
e7eb3a27 | 7 | * the Free Software Foundation, either version 3 of the License, or |
8e3fe3d8 | 8 | * (at your option) any later version. |
e7eb3a27 RK |
9 | * |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
8e3fe3d8 | 15 | * You should have received a copy of the GNU General Public License |
e7eb3a27 | 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
8e3fe3d8 | 17 | */ |
18 | /** @file clients/playrtp.h | |
19 | * @brief RTP player | |
20 | */ | |
21 | ||
22 | #ifndef PLAYRTP_H | |
23 | #define PLAYRTP_H | |
24 | ||
25 | /** @brief Maximum samples per packet we'll support | |
26 | * | |
27 | * NB that two channels = two samples in this program. | |
28 | */ | |
29 | #define MAXSAMPLES 2048 | |
30 | ||
31 | /** @brief Number of samples to infill by in one go | |
32 | * | |
33 | * This is an upper bound - in practice we expect the underlying audio API to | |
34 | * only ask for a much smaller number of samples in any one go. | |
35 | */ | |
36 | #define INFILL_SAMPLES (44100 * 2) /* 1s */ | |
37 | ||
38 | /** @brief Received packet | |
39 | * | |
40 | * Received packets are kept in a binary heap (see @ref pheap) ordered by | |
41 | * timestamp. | |
42 | */ | |
43 | struct packet { | |
44 | /** @brief Next packet in @ref next_free_packet or @ref received_packets */ | |
45 | struct packet *next; | |
46 | ||
47 | /** @brief Number of samples in this packet */ | |
48 | uint32_t nsamples; | |
49 | ||
50 | /** @brief Timestamp from RTP packet | |
51 | * | |
52 | * NB that "timestamps" are really sample counters. Use lt() or lt_packet() | |
53 | * to compare timestamps. | |
54 | */ | |
55 | uint32_t timestamp; | |
56 | ||
57 | /** @brief Flags | |
58 | * | |
59 | * Valid values are: | |
60 | * - @ref IDLE - the idle bit was set in the RTP packet | |
67d308e7 | 61 | * - @ref SILENT - packet is entirely silent |
8e3fe3d8 | 62 | */ |
63 | unsigned flags; | |
64 | /** @brief idle bit set in RTP packet*/ | |
65 | #define IDLE 0x0001 | |
66 | ||
67d308e7 RK |
67 | /** @brief RTP packet is entirely silent */ |
68 | #define SILENT 0x0002 | |
69 | ||
8e3fe3d8 | 70 | /** @brief Raw sample data |
71 | * | |
72 | * Only the first @p nsamples samples are defined; the rest is uninitialized | |
73 | * data. | |
74 | */ | |
75 | uint16_t samples_raw[MAXSAMPLES]; | |
76 | }; | |
77 | ||
78 | /** @brief Structure of free packet list */ | |
79 | union free_packet { | |
80 | struct packet p; | |
81 | union free_packet *next; | |
82 | }; | |
83 | ||
84 | /** @brief Return true iff \f$a < b\f$ in sequence-space arithmetic | |
85 | * | |
86 | * Specifically it returns true if \f$(a-b) mod 2^{32} < 2^{31}\f$. | |
87 | * | |
88 | * See also lt_packet(). | |
89 | */ | |
90 | static inline int lt(uint32_t a, uint32_t b) { | |
91 | return (uint32_t)(a - b) & 0x80000000; | |
92 | } | |
93 | ||
94 | /** @brief Return true iff a >= b in sequence-space arithmetic */ | |
95 | static inline int ge(uint32_t a, uint32_t b) { | |
96 | return !lt(a, b); | |
97 | } | |
98 | ||
99 | /** @brief Return true iff a > b in sequence-space arithmetic */ | |
100 | static inline int gt(uint32_t a, uint32_t b) { | |
101 | return lt(b, a); | |
102 | } | |
103 | ||
104 | /** @brief Return true iff a <= b in sequence-space arithmetic */ | |
105 | static inline int le(uint32_t a, uint32_t b) { | |
106 | return !lt(b, a); | |
107 | } | |
108 | ||
109 | /** @brief Ordering for packets, used by @ref pheap */ | |
110 | static inline int lt_packet(const struct packet *a, const struct packet *b) { | |
111 | return lt(a->timestamp, b->timestamp); | |
112 | } | |
113 | ||
c593cf7c | 114 | /** @brief Return true if @p p contains @p timestamp |
115 | * | |
116 | * Containment implies that a sample @p timestamp exists within the packet. | |
117 | */ | |
118 | static inline int contains(const struct packet *p, uint32_t timestamp) { | |
119 | const uint32_t packet_start = p->timestamp; | |
120 | const uint32_t packet_end = p->timestamp + p->nsamples; | |
121 | ||
122 | return (ge(timestamp, packet_start) | |
123 | && lt(timestamp, packet_end)); | |
124 | } | |
125 | ||
8e3fe3d8 | 126 | /** @struct pheap |
127 | * @brief Binary heap of packets ordered by timestamp */ | |
128 | HEAP_TYPE(pheap, struct packet *, lt_packet); | |
129 | ||
c593cf7c | 130 | struct packet *playrtp_new_packet(void); |
131 | void playrtp_free_packet(struct packet *p); | |
132 | void playrtp_fill_buffer(void); | |
133 | struct packet *playrtp_next_packet(void); | |
8e3fe3d8 | 134 | |
8e3fe3d8 | 135 | extern struct packet *received_packets; |
136 | extern struct packet **received_tail; | |
137 | extern pthread_mutex_t receive_lock; | |
138 | extern pthread_cond_t receive_cond; | |
139 | extern uint32_t nreceived; | |
140 | extern struct pheap packets; | |
141 | extern volatile uint32_t nsamples; | |
142 | extern uint32_t next_timestamp; | |
143 | extern int active; | |
144 | extern pthread_mutex_t lock; | |
145 | extern pthread_cond_t cond; | |
c593cf7c | 146 | extern unsigned minbuffer; |
8e3fe3d8 | 147 | |
e9b635a3 RK |
148 | extern int16_t *dump_buffer; |
149 | extern size_t dump_index; | |
150 | extern size_t dump_size; | |
151 | ||
c593cf7c | 152 | void playrtp_oss(void), playrtp_alsa(void), playrtp_coreaudio(void); |
8e3fe3d8 | 153 | |
154 | #endif /* PLAYRTP_H */ | |
155 | ||
156 | /* | |
157 | Local Variables: | |
158 | c-basic-offset:2 | |
159 | comment-column:40 | |
160 | fill-column:79 | |
161 | indent-tabs-mode:nil | |
162 | End: | |
163 | */ |