lavfi: implement asettb filter.

Changelog

@@ -21,6 +21,7 @@ version next:
 - RealText demuxer and decoder
 - Heart Of Darkness PAF playback support
 - iec61883 device
+- asettb filter
 
 
 version 0.11:

doc/filters.texi

@@ -2937,14 +2937,15 @@ setpts=N/(25*TB)
 setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
 @end example
 
-@section settb
+@section settb, asettb
 
 Set the timebase to use for the output frames timestamps.
 It is mainly useful for testing timebase configuration.
 
 It accepts in input an arithmetic expression representing a rational.
 The expression can contain the constants "AVTB" (the
-default timebase), and "intb" (the input timebase).
+default timebase), "intb" (the input timebase) and "sr" (the sample rate,
+audio only).
 
 The default value for the input is "intb".
 

libavfilter/Makefile

@@ -53,6 +53,7 @@ OBJS-$(CONFIG_AMIX_FILTER)                   += af_amix.o
 OBJS-$(CONFIG_ANULL_FILTER)                  += af_anull.o
 OBJS-$(CONFIG_ARESAMPLE_FILTER)              += af_aresample.o
 OBJS-$(CONFIG_ASETNSAMPLES_FILTER)           += af_asetnsamples.o
+OBJS-$(CONFIG_ASETTB_FILTER)                 += vf_settb.o
 OBJS-$(CONFIG_ASHOWINFO_FILTER)              += af_ashowinfo.o
 OBJS-$(CONFIG_ASPLIT_FILTER)                 += split.o
 OBJS-$(CONFIG_ASTREAMSYNC_FILTER)            += af_astreamsync.o

libavfilter/allfilters.c

@@ -42,6 +42,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER (ANULL,       anull,       af);
     REGISTER_FILTER (ARESAMPLE,   aresample,   af);
     REGISTER_FILTER (ASETNSAMPLES, asetnsamples, af);
+    REGISTER_FILTER (ASETTB,      asettb,      af);
     REGISTER_FILTER (ASHOWINFO,   ashowinfo,   af);
     REGISTER_FILTER (ASPLIT,      asplit,      af);
     REGISTER_FILTER (ASTREAMSYNC, astreamsync, af);

libavfilter/version.h

@@ -29,8 +29,8 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  0
+#define LIBAVFILTER_VERSION_MINOR  1
-#define LIBAVFILTER_VERSION_MICRO 101
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \

libavfilter/vf_settb.c

@@ -29,17 +29,20 @@
 #include "libavutil/rational.h"
 #include "avfilter.h"
 #include "internal.h"
+#include "audio.h"
 #include "video.h"
 
 static const char *const var_names[] = {
     "AVTB",   /* default timebase 1/AV_TIME_BASE */
     "intb",   /* input timebase */
+    "sr",     /* sample rate */
     NULL
 };
 
 enum var_name {
     VAR_AVTB,
     VAR_INTB,
+    VAR_SR,
     VAR_VARS_NB
 };
 
@@ -70,6 +73,7 @@ static int config_output_props(AVFilterLink *outlink)
 
     settb->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q);
     settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
+    settb->var_values[VAR_SR]   = inlink->sample_rate;
 
     outlink->w = inlink->w;
     outlink->h = inlink->h;
@@ -113,9 +117,28 @@ static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
     ff_start_frame(outlink, picref2);
 }
 
+static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
+{
+    AVFilterContext *ctx = inlink->dst;
+    AVFilterLink *outlink = ctx->outputs[0];
+    AVFilterBufferRef *outsamples = insamples;
+
+    if (av_cmp_q(inlink->time_base, outlink->time_base)) {
+        outsamples = avfilter_ref_buffer(insamples, ~0);
+        outsamples->pts = av_rescale_q(insamples->pts, inlink->time_base, outlink->time_base);
+        av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
+               inlink ->time_base.num, inlink ->time_base.den, insamples ->pts,
+               outlink->time_base.num, outlink->time_base.den, outsamples->pts);
+        avfilter_unref_buffer(insamples);
+    }
+
+    ff_filter_samples(outlink, outsamples);
+}
+
+#if CONFIG_SETTB_FILTER
 AVFilter avfilter_vf_settb = {
     .name      = "settb",
-    .description = NULL_IF_CONFIG_SMALL("Set timebase for the output link."),
+    .description = NULL_IF_CONFIG_SMALL("Set timebase for the video output link."),
     .init      = init,
 
     .priv_size = sizeof(SetTBContext),
@@ -132,3 +155,28 @@ AVFilter avfilter_vf_settb = {
                                     .config_props    = config_output_props, },
                                   { .name = NULL}},
 };
+#endif
+
+#if CONFIG_ASETTB_FILTER
+AVFilter avfilter_af_asettb = {
+    .name      = "asettb",
+    .description = NULL_IF_CONFIG_SMALL("Set timebase for the audio output link."),
+    .init      = init,
+
+    .priv_size = sizeof(SetTBContext),
+
+    .inputs    = (const AVFilterPad[]) {
+        { .name             = "default",
+          .type             = AVMEDIA_TYPE_AUDIO,
+          .get_audio_buffer = ff_null_get_audio_buffer,
+          .filter_samples   = filter_samples, },
+        { .name = NULL }
+    },
+    .outputs   = (const AVFilterPad[]) {
+        { .name            = "default",
+          .type            = AVMEDIA_TYPE_AUDIO,
+          .config_props    = config_output_props, },
+        { .name = NULL}
+    },
+};
+#endif