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-rw-r--r--libavfilter/af_astreamsync.c240
1 files changed, 240 insertions, 0 deletions
diff --git a/libavfilter/af_astreamsync.c b/libavfilter/af_astreamsync.c
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+++ b/libavfilter/af_astreamsync.c
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+/*
+ * 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 Lesser 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 "libavutil/opt.h"
+#include "avfilter.h"
+#include "audio.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 {
+ const AVClass *class;
+ AVExpr *expr;
+ char *expr_str;
+ double var_values[VAR_NB];
+ struct buf_queue {
+ AVFrame *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;
+
+#define OFFSET(x) offsetof(AStreamSyncContext, x)
+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption astreamsync_options[] = {
+ { "expr", "set stream selection expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "t1-t2" }, .flags = FLAGS },
+ { "e", "set stream selection expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "t1-t2" }, .flags = FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(astreamsync);
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ AStreamSyncContext *as = ctx->priv;
+ int r, i;
+
+ r = av_expr_parse(&as->expr, as->expr_str, var_names,
+ NULL, NULL, NULL, NULL, 0, ctx);
+ if (r < 0) {
+ av_log(ctx, AV_LOG_ERROR, "Error in expression \"%s\"\n", as->expr_str);
+ 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, *rates;
+ AVFilterChannelLayouts *layouts;
+
+ for (i = 0; i < 2; i++) {
+ formats = ctx->inputs[i]->in_formats;
+ ff_formats_ref(formats, &ctx->inputs[i]->out_formats);
+ ff_formats_ref(formats, &ctx->outputs[i]->in_formats);
+ rates = ff_all_samplerates();
+ ff_formats_ref(rates, &ctx->inputs[i]->out_samplerates);
+ ff_formats_ref(rates, &ctx->outputs[i]->in_samplerates);
+ layouts = ctx->inputs[i]->in_channel_layouts;
+ ff_channel_layouts_ref(layouts, &ctx->inputs[i]->out_channel_layouts);
+ ff_channel_layouts_ref(layouts, &ctx->outputs[i]->in_channel_layouts);
+ }
+ 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 int send_out(AVFilterContext *ctx, int out_id)
+{
+ AStreamSyncContext *as = ctx->priv;
+ struct buf_queue *queue = &as->queue[out_id];
+ AVFrame *buf = queue->buf[queue->tail];
+ int ret;
+
+ queue->buf[queue->tail] = NULL;
+ as->var_values[VAR_B1 + out_id]++;
+ as->var_values[VAR_S1 + out_id] += buf->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->nb_samples /
+ (double)ctx->inputs[out_id]->sample_rate;
+ ret = ff_filter_frame(ctx->outputs[out_id], buf);
+ queue->nb--;
+ queue->tail = (queue->tail + 1) % QUEUE_SIZE;
+ if (as->req[out_id])
+ as->req[out_id]--;
+ return ret;
+}
+
+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;
+ ff_request_frame(ctx->inputs[as->next_out]);
+ if (as->eof & (1 << as->next_out))
+ as->next_out = !as->next_out;
+ }
+ }
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *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);
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ AStreamSyncContext *as = ctx->priv;
+
+ av_expr_free(as->expr);
+ as->expr = NULL;
+}
+
+static const AVFilterPad astreamsync_inputs[] = {
+ {
+ .name = "in1",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .filter_frame = filter_frame,
+ },{
+ .name = "in2",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad astreamsync_outputs[] = {
+ {
+ .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,
+ },
+ { NULL }
+};
+
+AVFilter ff_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,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = astreamsync_inputs,
+ .outputs = astreamsync_outputs,
+ .priv_class = &astreamsync_class,
+};
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