1 /*
2 * Generic frame queue
3 * Copyright (c) 2016 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 License
9 * 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
15 * GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "libavutil/avassert.h"
23 #include "framequeue.h"
24
bucket(FFFrameQueue * fq,size_t idx)25 static inline FFFrameBucket *bucket(FFFrameQueue *fq, size_t idx)
26 {
27 return &fq->queue[(fq->tail + idx) & (fq->allocated - 1)];
28 }
29
ff_framequeue_global_init(FFFrameQueueGlobal * fqg)30 void ff_framequeue_global_init(FFFrameQueueGlobal *fqg)
31 {
32 }
33
check_consistency(FFFrameQueue * fq)34 static void check_consistency(FFFrameQueue *fq)
35 {
36 #if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
37 uint64_t nb_samples = 0;
38 size_t i;
39
40 av_assert0(fq->queued == fq->total_frames_head - fq->total_frames_tail);
41 for (i = 0; i < fq->queued; i++)
42 nb_samples += bucket(fq, i)->frame->nb_samples;
43 av_assert0(nb_samples == fq->total_samples_head - fq->total_samples_tail);
44 #endif
45 }
46
ff_framequeue_init(FFFrameQueue * fq,FFFrameQueueGlobal * fqg)47 void ff_framequeue_init(FFFrameQueue *fq, FFFrameQueueGlobal *fqg)
48 {
49 fq->queue = &fq->first_bucket;
50 fq->allocated = 1;
51 }
52
ff_framequeue_free(FFFrameQueue * fq)53 void ff_framequeue_free(FFFrameQueue *fq)
54 {
55 while (fq->queued) {
56 AVFrame *frame = ff_framequeue_take(fq);
57 av_frame_free(&frame);
58 }
59 if (fq->queue != &fq->first_bucket)
60 av_freep(&fq->queue);
61 }
62
ff_framequeue_add(FFFrameQueue * fq,AVFrame * frame)63 int ff_framequeue_add(FFFrameQueue *fq, AVFrame *frame)
64 {
65 FFFrameBucket *b;
66
67 check_consistency(fq);
68 if (fq->queued == fq->allocated) {
69 if (fq->allocated == 1) {
70 size_t na = 8;
71 FFFrameBucket *nq = av_realloc_array(NULL, na, sizeof(*nq));
72 if (!nq)
73 return AVERROR(ENOMEM);
74 nq[0] = fq->queue[0];
75 fq->queue = nq;
76 fq->allocated = na;
77 } else {
78 size_t na = fq->allocated << 1;
79 FFFrameBucket *nq = av_realloc_array(fq->queue, na, sizeof(*nq));
80 if (!nq)
81 return AVERROR(ENOMEM);
82 if (fq->tail + fq->queued > fq->allocated)
83 memmove(nq + fq->allocated, nq,
84 (fq->tail + fq->queued - fq->allocated) * sizeof(*nq));
85 fq->queue = nq;
86 fq->allocated = na;
87 }
88 }
89 b = bucket(fq, fq->queued);
90 b->frame = frame;
91 fq->queued++;
92 fq->total_frames_head++;
93 fq->total_samples_head += frame->nb_samples;
94 check_consistency(fq);
95 return 0;
96 }
97
ff_framequeue_take(FFFrameQueue * fq)98 AVFrame *ff_framequeue_take(FFFrameQueue *fq)
99 {
100 FFFrameBucket *b;
101
102 check_consistency(fq);
103 av_assert1(fq->queued);
104 b = bucket(fq, 0);
105 fq->queued--;
106 fq->tail++;
107 fq->tail &= fq->allocated - 1;
108 fq->total_frames_tail++;
109 fq->total_samples_tail += b->frame->nb_samples;
110 fq->samples_skipped = 0;
111 check_consistency(fq);
112 return b->frame;
113 }
114
ff_framequeue_peek(FFFrameQueue * fq,size_t idx)115 AVFrame *ff_framequeue_peek(FFFrameQueue *fq, size_t idx)
116 {
117 FFFrameBucket *b;
118
119 check_consistency(fq);
120 av_assert1(idx < fq->queued);
121 b = bucket(fq, idx);
122 check_consistency(fq);
123 return b->frame;
124 }
125
ff_framequeue_skip_samples(FFFrameQueue * fq,size_t samples,AVRational time_base)126 void ff_framequeue_skip_samples(FFFrameQueue *fq, size_t samples, AVRational time_base)
127 {
128 FFFrameBucket *b;
129 size_t bytes;
130 int planar, planes, i;
131
132 check_consistency(fq);
133 av_assert1(fq->queued);
134 b = bucket(fq, 0);
135 av_assert1(samples < b->frame->nb_samples);
136 planar = av_sample_fmt_is_planar(b->frame->format);
137 planes = planar ? b->frame->channels : 1;
138 bytes = samples * av_get_bytes_per_sample(b->frame->format);
139 if (!planar)
140 bytes *= b->frame->channels;
141 if (b->frame->pts != AV_NOPTS_VALUE)
142 b->frame->pts += av_rescale_q(samples, av_make_q(1, b->frame->sample_rate), time_base);
143 b->frame->nb_samples -= samples;
144 b->frame->linesize[0] -= bytes;
145 for (i = 0; i < planes; i++)
146 b->frame->extended_data[i] += bytes;
147 for (i = 0; i < planes && i < AV_NUM_DATA_POINTERS; i++)
148 b->frame->data[i] = b->frame->extended_data[i];
149 fq->total_samples_tail += samples;
150 fq->samples_skipped = 1;
151 ff_framequeue_update_peeked(fq, 0);
152 }
153