1 |
|
|
/* |
2 |
|
|
* Generic buffer queue |
3 |
|
|
* Copyright (c) 2012 Nicolas George |
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 |
|
|
#ifndef AVFILTER_BUFFERQUEUE_H |
23 |
|
|
#define AVFILTER_BUFFERQUEUE_H |
24 |
|
|
|
25 |
|
|
/** |
26 |
|
|
* FFBufQueue: simple AVFrame queue API |
27 |
|
|
* |
28 |
|
|
* Note: this API is not thread-safe. Concurrent access to the same queue |
29 |
|
|
* must be protected by a mutex or any synchronization mechanism. |
30 |
|
|
*/ |
31 |
|
|
|
32 |
|
|
/** |
33 |
|
|
* Maximum size of the queue. |
34 |
|
|
* |
35 |
|
|
* This value can be overridden by definying it before including this |
36 |
|
|
* header. |
37 |
|
|
* Powers of 2 are recommended. |
38 |
|
|
*/ |
39 |
|
|
#ifndef FF_BUFQUEUE_SIZE |
40 |
|
|
#define FF_BUFQUEUE_SIZE 64 |
41 |
|
|
#endif |
42 |
|
|
|
43 |
|
|
#include "avfilter.h" |
44 |
|
|
#include "libavutil/avassert.h" |
45 |
|
|
|
46 |
|
|
/** |
47 |
|
|
* Structure holding the queue |
48 |
|
|
*/ |
49 |
|
|
struct FFBufQueue { |
50 |
|
|
AVFrame *queue[FF_BUFQUEUE_SIZE]; |
51 |
|
|
unsigned short head; |
52 |
|
|
unsigned short available; /**< number of available buffers */ |
53 |
|
|
}; |
54 |
|
|
|
55 |
|
|
#define BUCKET(i) queue->queue[(queue->head + (i)) % FF_BUFQUEUE_SIZE] |
56 |
|
|
|
57 |
|
|
/** |
58 |
|
|
* Test if a buffer queue is full. |
59 |
|
|
*/ |
60 |
|
6560 |
static inline int ff_bufqueue_is_full(struct FFBufQueue *queue) |
61 |
|
|
{ |
62 |
|
6560 |
return queue->available == FF_BUFQUEUE_SIZE; |
63 |
|
|
} |
64 |
|
|
|
65 |
|
|
/** |
66 |
|
|
* Add a buffer to the queue. |
67 |
|
|
* |
68 |
|
|
* If the queue is already full, then the current last buffer is dropped |
69 |
|
|
* (and unrefed) with a warning before adding the new buffer. |
70 |
|
|
*/ |
71 |
|
6560 |
static inline void ff_bufqueue_add(void *log, struct FFBufQueue *queue, |
72 |
|
|
AVFrame *buf) |
73 |
|
|
{ |
74 |
✗✓ |
6560 |
if (ff_bufqueue_is_full(queue)) { |
75 |
|
|
av_log(log, AV_LOG_WARNING, "Buffer queue overflow, dropping.\n"); |
76 |
|
|
av_frame_free(&BUCKET(--queue->available)); |
77 |
|
|
} |
78 |
|
6560 |
BUCKET(queue->available++) = buf; |
79 |
|
6560 |
} |
80 |
|
|
|
81 |
|
|
/** |
82 |
|
|
* Get a buffer from the queue without altering it. |
83 |
|
|
* |
84 |
|
|
* Buffer with index 0 is the first buffer in the queue. |
85 |
|
|
* Return NULL if the queue has not enough buffers. |
86 |
|
|
*/ |
87 |
|
|
static inline AVFrame *ff_bufqueue_peek(struct FFBufQueue *queue, |
88 |
|
|
unsigned index) |
89 |
|
|
{ |
90 |
|
|
return index < queue->available ? BUCKET(index) : NULL; |
91 |
|
|
} |
92 |
|
|
|
93 |
|
|
/** |
94 |
|
|
* Get the first buffer from the queue and remove it. |
95 |
|
|
* |
96 |
|
|
* Do not use on an empty queue. |
97 |
|
|
*/ |
98 |
|
6560 |
static inline AVFrame *ff_bufqueue_get(struct FFBufQueue *queue) |
99 |
|
|
{ |
100 |
|
6560 |
AVFrame *ret = queue->queue[queue->head]; |
101 |
✗✓ |
6560 |
av_assert0(queue->available); |
102 |
|
6560 |
queue->available--; |
103 |
|
6560 |
queue->queue[queue->head] = NULL; |
104 |
|
6560 |
queue->head = (queue->head + 1) % FF_BUFQUEUE_SIZE; |
105 |
|
6560 |
return ret; |
106 |
|
|
} |
107 |
|
|
|
108 |
|
|
/** |
109 |
|
|
* Unref and remove all buffers from the queue. |
110 |
|
|
*/ |
111 |
|
1 |
static inline void ff_bufqueue_discard_all(struct FFBufQueue *queue) |
112 |
|
|
{ |
113 |
✗✓ |
1 |
while (queue->available) { |
114 |
|
|
AVFrame *buf = ff_bufqueue_get(queue); |
115 |
|
|
av_frame_free(&buf); |
116 |
|
|
} |
117 |
|
1 |
} |
118 |
|
|
|
119 |
|
|
#undef BUCKET |
120 |
|
|
|
121 |
|
|
#endif /* AVFILTER_BUFFERQUEUE_H */ |