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 ff_formats_ref(formats, &ctx->inputs[i]->out_formats);
99 ff_formats_ref(formats, &ctx->outputs[i]->in_formats);
100 rates = ff_all_samplerates();
101 ff_formats_ref(rates, &ctx->inputs[i]->out_samplerates);
102 ff_formats_ref(rates, &ctx->outputs[i]->in_samplerates);
103 layouts = ctx->inputs[i]->in_channel_layouts;
104 ff_channel_layouts_ref(layouts, &ctx->inputs[i]->out_channel_layouts);
105 ff_channel_layouts_ref(layouts, &ctx->outputs[i]->in_channel_layouts);
110 static int config_output(AVFilterLink *outlink)
112 AVFilterContext *ctx = outlink->src;
113 int id = outlink == ctx->outputs[1];
115 outlink->sample_rate = ctx->inputs[id]->sample_rate;
116 outlink->time_base = ctx->inputs[id]->time_base;
120 static int send_out(AVFilterContext *ctx, int out_id)
122 AStreamSyncContext *as = ctx->priv;
123 struct buf_queue *queue = &as->queue[out_id];
124 AVFrame *buf = queue->buf[queue->tail];
127 queue->buf[queue->tail] = NULL;
128 as->var_values[VAR_B1 + out_id]++;
129 as->var_values[VAR_S1 + out_id] += buf->nb_samples;
130 if (buf->pts != AV_NOPTS_VALUE)
131 as->var_values[VAR_T1 + out_id] =
132 av_q2d(ctx->outputs[out_id]->time_base) * buf->pts;
133 as->var_values[VAR_T1 + out_id] += buf->nb_samples /
134 (double)ctx->inputs[out_id]->sample_rate;
135 ret = ff_filter_frame(ctx->outputs[out_id], buf);
137 queue->tail = (queue->tail + 1) % QUEUE_SIZE;
143 static void send_next(AVFilterContext *ctx)
145 AStreamSyncContext *as = ctx->priv;
149 if (!as->queue[as->next_out].nb)
151 send_out(ctx, as->next_out);
153 as->next_out = av_expr_eval(as->expr, as->var_values, NULL) >= 0;
155 for (i = 0; i < 2; i++)
156 if (as->queue[i].nb == QUEUE_SIZE)
160 static int request_frame(AVFilterLink *outlink)
162 AVFilterContext *ctx = outlink->src;
163 AStreamSyncContext *as = ctx->priv;
164 int id = outlink == ctx->outputs[1];
167 while (as->req[id] && !(as->eof & (1 << id))) {
168 if (as->queue[as->next_out].nb) {
171 as->eof |= 1 << as->next_out;
172 ff_request_frame(ctx->inputs[as->next_out]);
173 if (as->eof & (1 << as->next_out))
174 as->next_out = !as->next_out;
180 static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
182 AVFilterContext *ctx = inlink->dst;
183 AStreamSyncContext *as = ctx->priv;
184 int id = inlink == ctx->inputs[1];
186 as->queue[id].buf[(as->queue[id].tail + as->queue[id].nb++) % QUEUE_SIZE] =
188 as->eof &= ~(1 << id);
193 static av_cold void uninit(AVFilterContext *ctx)
195 AStreamSyncContext *as = ctx->priv;
197 av_expr_free(as->expr);
201 static const AVFilterPad astreamsync_inputs[] = {
204 .type = AVMEDIA_TYPE_AUDIO,
205 .filter_frame = filter_frame,
208 .type = AVMEDIA_TYPE_AUDIO,
209 .filter_frame = filter_frame,
214 static const AVFilterPad astreamsync_outputs[] = {
217 .type = AVMEDIA_TYPE_AUDIO,
218 .config_props = config_output,
219 .request_frame = request_frame,
222 .type = AVMEDIA_TYPE_AUDIO,
223 .config_props = config_output,
224 .request_frame = request_frame,
229 AVFilter ff_af_astreamsync = {
230 .name = "astreamsync",
231 .description = NULL_IF_CONFIG_SMALL("Copy two streams of audio data "
232 "in a configurable order."),
233 .priv_size = sizeof(AStreamSyncContext),
236 .query_formats = query_formats,
237 .inputs = astreamsync_inputs,
238 .outputs = astreamsync_outputs,
239 .priv_class = &astreamsync_class,