1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
/*
* Copyright (c) 2011 Nicolas George <nicolas.george@normalesup.org>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Stream (de)synchronization filter
*/
#include "libavutil/eval.h"
#include "avfilter.h"
#include "internal.h"
#define QUEUE_SIZE 16
static const char * const var_names[] = {
"b1", "b2",
"s1", "s2",
"t1", "t2",
NULL
};
enum var_name {
VAR_B1, VAR_B2,
VAR_S1, VAR_S2,
VAR_T1, VAR_T2,
VAR_NB
};
typedef struct {
AVExpr *expr;
double var_values[VAR_NB];
struct buf_queue {
AVFilterBufferRef *buf[QUEUE_SIZE];
unsigned tail, nb;
/* buf[tail] is the oldest,
buf[(tail + nb) % QUEUE_SIZE] is where the next is added */
} queue[2];
int req[2];
int next_out;
int eof; /* bitmask, one bit for each stream */
} AStreamSyncContext;
static const char *default_expr = "t1-t2";
static av_cold int init(AVFilterContext *ctx, const char *args0, void *opaque)
{
AStreamSyncContext *as = ctx->priv;
const char *expr = args0 ? args0 : default_expr;
int r, i;
r = av_expr_parse(&as->expr, expr, var_names,
NULL, NULL, NULL, NULL, 0, ctx);
if (r < 0) {
av_log(ctx, AV_LOG_ERROR, "Error in expression \"%s\"\n", expr);
return r;
}
for (i = 0; i < 42; i++)
av_expr_eval(as->expr, as->var_values, NULL); /* exercize prng */
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
int i;
AVFilterFormats *formats;
for (i = 0; i < 2; i++) {
formats = ctx->inputs[i]->in_formats;
avfilter_formats_ref(formats, &ctx->inputs[i]->out_formats);
avfilter_formats_ref(formats, &ctx->outputs[i]->in_formats);
formats = ctx->inputs[i]->in_packing;
avfilter_formats_ref(formats, &ctx->inputs[i]->out_packing);
avfilter_formats_ref(formats, &ctx->outputs[i]->in_packing);
formats = ctx->inputs[i]->in_chlayouts;
avfilter_formats_ref(formats, &ctx->inputs[i]->out_chlayouts);
avfilter_formats_ref(formats, &ctx->outputs[i]->in_chlayouts);
}
return 0;
}
static int config_output(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
int id = outlink == ctx->outputs[1];
outlink->sample_rate = ctx->inputs[id]->sample_rate;
outlink->time_base = ctx->inputs[id]->time_base;
return 0;
}
static void send_out(AVFilterContext *ctx, int out_id)
{
AStreamSyncContext *as = ctx->priv;
struct buf_queue *queue = &as->queue[out_id];
AVFilterBufferRef *buf = queue->buf[queue->tail];
queue->buf[queue->tail] = NULL;
as->var_values[VAR_B1 + out_id]++;
as->var_values[VAR_S1 + out_id] += buf->audio->nb_samples;
if (buf->pts != AV_NOPTS_VALUE)
as->var_values[VAR_T1 + out_id] =
av_q2d(ctx->outputs[out_id]->time_base) * buf->pts;
as->var_values[VAR_T1 + out_id] += buf->audio->nb_samples /
(double)ctx->inputs[out_id]->sample_rate;
avfilter_filter_samples(ctx->outputs[out_id], buf);
queue->nb--;
queue->tail = (queue->tail + 1) % QUEUE_SIZE;
if (as->req[out_id])
as->req[out_id]--;
}
static void send_next(AVFilterContext *ctx)
{
AStreamSyncContext *as = ctx->priv;
int i;
while (1) {
if (!as->queue[as->next_out].nb)
break;
send_out(ctx, as->next_out);
if (!as->eof)
as->next_out = av_expr_eval(as->expr, as->var_values, NULL) >= 0;
}
for (i = 0; i < 2; i++)
if (as->queue[i].nb == QUEUE_SIZE)
send_out(ctx, i);
}
static int request_frame(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
AStreamSyncContext *as = ctx->priv;
int id = outlink == ctx->outputs[1];
as->req[id]++;
while (as->req[id] && !(as->eof & (1 << id))) {
if (as->queue[as->next_out].nb) {
send_next(ctx);
} else {
as->eof |= 1 << as->next_out;
avfilter_request_frame(ctx->inputs[as->next_out]);
if (as->eof & (1 << as->next_out))
as->next_out = !as->next_out;
}
}
return 0;
}
static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
{
AVFilterContext *ctx = inlink->dst;
AStreamSyncContext *as = ctx->priv;
int id = inlink == ctx->inputs[1];
as->queue[id].buf[(as->queue[id].tail + as->queue[id].nb++) % QUEUE_SIZE] =
insamples;
as->eof &= ~(1 << id);
send_next(ctx);
}
AVFilter avfilter_af_astreamsync = {
.name = "astreamsync",
.description = NULL_IF_CONFIG_SMALL("Copy two streams of audio data "
"in a configurable order."),
.priv_size = sizeof(AStreamSyncContext),
.init = init,
.query_formats = query_formats,
.inputs = (const AVFilterPad[]) {
{ .name = "in1",
.type = AVMEDIA_TYPE_AUDIO,
.filter_samples = filter_samples,
.min_perms = AV_PERM_READ, },
{ .name = "in2",
.type = AVMEDIA_TYPE_AUDIO,
.filter_samples = filter_samples,
.min_perms = AV_PERM_READ, },
{ .name = NULL }
},
.outputs = (const AVFilterPad[]) {
{ .name = "out1",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_output,
.request_frame = request_frame, },
{ .name = "out2",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_output,
.request_frame = request_frame, },
{ .name = NULL }
},
};
|
