2 * Copyright (c) 2011 Nicolas George <nicolas.george@normalesup.org>
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * Stream (de)synchronization filter
26 #include "libavutil/eval.h"
27 #include "libavutil/opt.h"
34 static const char * const var_names[] = {
52 double var_values[VAR_NB];
54 AVFrame *buf[QUEUE_SIZE];
56 /* buf[tail] is the oldest,
57 buf[(tail + nb) % QUEUE_SIZE] is where the next is added */
61 int eof; /* bitmask, one bit for each stream */
64 #define OFFSET(x) offsetof(AStreamSyncContext, x)
65 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
66 static const AVOption astreamsync_options[] = {
67 { "expr", "set stream selection expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "t1-t2" }, .flags = FLAGS },
68 { "e", "set stream selection expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "t1-t2" }, .flags = FLAGS },
72 AVFILTER_DEFINE_CLASS(astreamsync);
74 static av_cold int init(AVFilterContext *ctx)
76 AStreamSyncContext *as = ctx->priv;
79 r = av_expr_parse(&as->expr, as->expr_str, var_names,
80 NULL, NULL, NULL, NULL, 0, ctx);
82 av_log(ctx, AV_LOG_ERROR, "Error in expression \"%s\"\n", as->expr_str);
85 for (i = 0; i < 42; i++)
86 av_expr_eval(as->expr, as->var_values, NULL); /* exercize prng */
90 static int query_formats(AVFilterContext *ctx)
93 AVFilterFormats *formats, *rates;
94 AVFilterChannelLayouts *layouts;
96 for (i = 0; i < 2; i++) {
97 formats = ctx->inputs[i]->in_formats;
98 if ((ret = ff_formats_ref(formats, &ctx->inputs[i]->out_formats)) < 0 ||
99 (ret = ff_formats_ref(formats, &ctx->outputs[i]->in_formats)) < 0)
101 rates = ff_all_samplerates();
102 if ((ret = ff_formats_ref(rates, &ctx->inputs[i]->out_samplerates)) < 0 ||
103 (ret = ff_formats_ref(rates, &ctx->outputs[i]->in_samplerates)) < 0)
105 layouts = ctx->inputs[i]->in_channel_layouts;
106 if ((ret = ff_channel_layouts_ref(layouts, &ctx->inputs[i]->out_channel_layouts)) < 0 ||
107 (ret = ff_channel_layouts_ref(layouts, &ctx->outputs[i]->in_channel_layouts)) < 0)
113 static int config_output(AVFilterLink *outlink)
115 AVFilterContext *ctx = outlink->src;
116 int id = outlink == ctx->outputs[1];
118 outlink->sample_rate = ctx->inputs[id]->sample_rate;
119 outlink->time_base = ctx->inputs[id]->time_base;
123 static int send_out(AVFilterContext *ctx, int out_id)
125 AStreamSyncContext *as = ctx->priv;
126 struct buf_queue *queue = &as->queue[out_id];
127 AVFrame *buf = queue->buf[queue->tail];
130 queue->buf[queue->tail] = NULL;
131 as->var_values[VAR_B1 + out_id]++;
132 as->var_values[VAR_S1 + out_id] += buf->nb_samples;
133 if (buf->pts != AV_NOPTS_VALUE)
134 as->var_values[VAR_T1 + out_id] =
135 av_q2d(ctx->outputs[out_id]->time_base) * buf->pts;
136 as->var_values[VAR_T1 + out_id] += buf->nb_samples /
137 (double)ctx->inputs[out_id]->sample_rate;
138 ret = ff_filter_frame(ctx->outputs[out_id], buf);
140 queue->tail = (queue->tail + 1) % QUEUE_SIZE;
146 static void send_next(AVFilterContext *ctx)
148 AStreamSyncContext *as = ctx->priv;
152 if (!as->queue[as->next_out].nb)
154 send_out(ctx, as->next_out);
156 as->next_out = av_expr_eval(as->expr, as->var_values, NULL) >= 0;
158 for (i = 0; i < 2; i++)
159 if (as->queue[i].nb == QUEUE_SIZE)
163 static int request_frame(AVFilterLink *outlink)
165 AVFilterContext *ctx = outlink->src;
166 AStreamSyncContext *as = ctx->priv;
167 int id = outlink == ctx->outputs[1];
170 while (as->req[id] && !(as->eof & (1 << id))) {
171 if (as->queue[as->next_out].nb) {
174 as->eof |= 1 << as->next_out;
175 ff_request_frame(ctx->inputs[as->next_out]);
176 if (as->eof & (1 << as->next_out))
177 as->next_out = !as->next_out;
183 static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
185 AVFilterContext *ctx = inlink->dst;
186 AStreamSyncContext *as = ctx->priv;
187 int id = inlink == ctx->inputs[1];
189 as->queue[id].buf[(as->queue[id].tail + as->queue[id].nb++) % QUEUE_SIZE] =
191 as->eof &= ~(1 << id);
196 static av_cold void uninit(AVFilterContext *ctx)
198 AStreamSyncContext *as = ctx->priv;
200 av_expr_free(as->expr);
204 static const AVFilterPad astreamsync_inputs[] = {
207 .type = AVMEDIA_TYPE_AUDIO,
208 .filter_frame = filter_frame,
211 .type = AVMEDIA_TYPE_AUDIO,
212 .filter_frame = filter_frame,
217 static const AVFilterPad astreamsync_outputs[] = {
220 .type = AVMEDIA_TYPE_AUDIO,
221 .config_props = config_output,
222 .request_frame = request_frame,
225 .type = AVMEDIA_TYPE_AUDIO,
226 .config_props = config_output,
227 .request_frame = request_frame,
232 AVFilter ff_af_astreamsync = {
233 .name = "astreamsync",
234 .description = NULL_IF_CONFIG_SMALL("Copy two streams of audio data "
235 "in a configurable order."),
236 .priv_size = sizeof(AStreamSyncContext),
239 .query_formats = query_formats,
240 .inputs = astreamsync_inputs,
241 .outputs = astreamsync_outputs,
242 .priv_class = &astreamsync_class,