FFmpeg  1.2.12
bufferqueue.h
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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 
39 #ifndef FF_BUFQUEUE_SIZE
40 #define FF_BUFQUEUE_SIZE 32
41 #endif
42 
43 #include "avfilter.h"
44 #include "libavutil/avassert.h"
45 
49 struct FFBufQueue {
51  unsigned short head;
52  unsigned short available;
53 };
54 
55 #define BUCKET(i) queue->queue[(queue->head + (i)) % FF_BUFQUEUE_SIZE]
56 
60 static inline int ff_bufqueue_is_full(struct FFBufQueue *queue)
61 {
62  return queue->available == FF_BUFQUEUE_SIZE;
63 }
64 
71 static inline void ff_bufqueue_add(void *log, struct FFBufQueue *queue,
72  AVFilterBufferRef *buf)
73 {
74  if (ff_bufqueue_is_full(queue)) {
75  av_log(log, AV_LOG_WARNING, "Buffer queue overflow, dropping.\n");
77  }
78  BUCKET(queue->available++) = buf;
79 }
80 
87 static inline AVFilterBufferRef *ff_bufqueue_peek(struct FFBufQueue *queue,
88  unsigned index)
89 {
90  return index < queue->available ? BUCKET(index) : NULL;
91 }
92 
98 static inline AVFilterBufferRef *ff_bufqueue_get(struct FFBufQueue *queue)
99 {
100  AVFilterBufferRef *ret = queue->queue[queue->head];
101  av_assert0(queue->available);
102  queue->available--;
103  queue->queue[queue->head] = NULL;
104  queue->head = (queue->head + 1) % FF_BUFQUEUE_SIZE;
105  return ret;
106 }
107 
111 static inline void ff_bufqueue_discard_all(struct FFBufQueue *queue)
112 {
113  while (queue->available)
115 }
116 
117 #undef BUCKET
118 
119 #endif /* AVFILTER_BUFFERQUEUE_H */