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8e3fe3d8 | 1 | /* |
2 | * This file is part of DisOrder. | |
3 | * Copyright (C) 2007 Richard Kettlewell | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
18 | * USA | |
19 | */ | |
20 | /** @file clients/playrtp.h | |
21 | * @brief RTP player | |
22 | */ | |
23 | ||
24 | #ifndef PLAYRTP_H | |
25 | #define PLAYRTP_H | |
26 | ||
27 | /** @brief Maximum samples per packet we'll support | |
28 | * | |
29 | * NB that two channels = two samples in this program. | |
30 | */ | |
31 | #define MAXSAMPLES 2048 | |
32 | ||
33 | /** @brief Number of samples to infill by in one go | |
34 | * | |
35 | * This is an upper bound - in practice we expect the underlying audio API to | |
36 | * only ask for a much smaller number of samples in any one go. | |
37 | */ | |
38 | #define INFILL_SAMPLES (44100 * 2) /* 1s */ | |
39 | ||
40 | /** @brief Received packet | |
41 | * | |
42 | * Received packets are kept in a binary heap (see @ref pheap) ordered by | |
43 | * timestamp. | |
44 | */ | |
45 | struct packet { | |
46 | /** @brief Next packet in @ref next_free_packet or @ref received_packets */ | |
47 | struct packet *next; | |
48 | ||
49 | /** @brief Number of samples in this packet */ | |
50 | uint32_t nsamples; | |
51 | ||
52 | /** @brief Timestamp from RTP packet | |
53 | * | |
54 | * NB that "timestamps" are really sample counters. Use lt() or lt_packet() | |
55 | * to compare timestamps. | |
56 | */ | |
57 | uint32_t timestamp; | |
58 | ||
59 | /** @brief Flags | |
60 | * | |
61 | * Valid values are: | |
62 | * - @ref IDLE - the idle bit was set in the RTP packet | |
63 | */ | |
64 | unsigned flags; | |
65 | /** @brief idle bit set in RTP packet*/ | |
66 | #define IDLE 0x0001 | |
67 | ||
68 | /** @brief Raw sample data | |
69 | * | |
70 | * Only the first @p nsamples samples are defined; the rest is uninitialized | |
71 | * data. | |
72 | */ | |
73 | uint16_t samples_raw[MAXSAMPLES]; | |
74 | }; | |
75 | ||
76 | /** @brief Structure of free packet list */ | |
77 | union free_packet { | |
78 | struct packet p; | |
79 | union free_packet *next; | |
80 | }; | |
81 | ||
82 | /** @brief Return true iff \f$a < b\f$ in sequence-space arithmetic | |
83 | * | |
84 | * Specifically it returns true if \f$(a-b) mod 2^{32} < 2^{31}\f$. | |
85 | * | |
86 | * See also lt_packet(). | |
87 | */ | |
88 | static inline int lt(uint32_t a, uint32_t b) { | |
89 | return (uint32_t)(a - b) & 0x80000000; | |
90 | } | |
91 | ||
92 | /** @brief Return true iff a >= b in sequence-space arithmetic */ | |
93 | static inline int ge(uint32_t a, uint32_t b) { | |
94 | return !lt(a, b); | |
95 | } | |
96 | ||
97 | /** @brief Return true iff a > b in sequence-space arithmetic */ | |
98 | static inline int gt(uint32_t a, uint32_t b) { | |
99 | return lt(b, a); | |
100 | } | |
101 | ||
102 | /** @brief Return true iff a <= b in sequence-space arithmetic */ | |
103 | static inline int le(uint32_t a, uint32_t b) { | |
104 | return !lt(b, a); | |
105 | } | |
106 | ||
107 | /** @brief Ordering for packets, used by @ref pheap */ | |
108 | static inline int lt_packet(const struct packet *a, const struct packet *b) { | |
109 | return lt(a->timestamp, b->timestamp); | |
110 | } | |
111 | ||
c593cf7c | 112 | /** @brief Return true if @p p contains @p timestamp |
113 | * | |
114 | * Containment implies that a sample @p timestamp exists within the packet. | |
115 | */ | |
116 | static inline int contains(const struct packet *p, uint32_t timestamp) { | |
117 | const uint32_t packet_start = p->timestamp; | |
118 | const uint32_t packet_end = p->timestamp + p->nsamples; | |
119 | ||
120 | return (ge(timestamp, packet_start) | |
121 | && lt(timestamp, packet_end)); | |
122 | } | |
123 | ||
8e3fe3d8 | 124 | /** @struct pheap |
125 | * @brief Binary heap of packets ordered by timestamp */ | |
126 | HEAP_TYPE(pheap, struct packet *, lt_packet); | |
127 | ||
c593cf7c | 128 | struct packet *playrtp_new_packet(void); |
129 | void playrtp_free_packet(struct packet *p); | |
130 | void playrtp_fill_buffer(void); | |
131 | struct packet *playrtp_next_packet(void); | |
8e3fe3d8 | 132 | |
133 | extern const char *device; | |
134 | extern struct packet *received_packets; | |
135 | extern struct packet **received_tail; | |
136 | extern pthread_mutex_t receive_lock; | |
137 | extern pthread_cond_t receive_cond; | |
138 | extern uint32_t nreceived; | |
139 | extern struct pheap packets; | |
140 | extern volatile uint32_t nsamples; | |
141 | extern uint32_t next_timestamp; | |
142 | extern int active; | |
143 | extern pthread_mutex_t lock; | |
144 | extern pthread_cond_t cond; | |
c593cf7c | 145 | extern unsigned minbuffer; |
8e3fe3d8 | 146 | |
e9b635a3 RK |
147 | extern int16_t *dump_buffer; |
148 | extern size_t dump_index; | |
149 | extern size_t dump_size; | |
150 | ||
c593cf7c | 151 | void playrtp_oss(void), playrtp_alsa(void), playrtp_coreaudio(void); |
8e3fe3d8 | 152 | |
153 | #endif /* PLAYRTP_H */ | |
154 | ||
155 | /* | |
156 | Local Variables: | |
157 | c-basic-offset:2 | |
158 | comment-column:40 | |
159 | fill-column:79 | |
160 | indent-tabs-mode:nil | |
161 | End: | |
162 | */ |