@@ -41,6 +41,7 @@ version <next>:

 - VobSub demuxer

 - JSON captions for TED talks decoding support

 - SOX Resampler support in libswresample

+- aselect filter

 version 1.0:

@@ -3506,7 +3506,7 @@ scale='min(500\, iw*3/2):-1'

 @end example

 @end itemize

-@section select

+@section aselect, select

 Select frames to pass in output.

 It accepts in input an expression, which is evaluated for each input

@@ -3551,7 +3551,7 @@ the PTS of the first video frame in the video, NAN if undefined

 @item start_t

 the time of the first video frame in the video, NAN if undefined

-@item pict_type

+@item pict_type @emph{(video only)}

 the type of the filtered frame, can assume one of the following

 values:

 @table @option

@@ -3564,7 +3564,7 @@ values:

 @item BI

 @end table

-@item interlace_type

+@item interlace_type @emph{(video only)}

 the frame interlace type, can assume one of the following values:

 @table @option

 @item PROGRESSIVE

@@ -3575,6 +3575,15 @@ the frame is top-field-first

 the frame is bottom-field-first

 @end table

+@item consumed_sample_n @emph{(audio only)}

+the number of selected samples before the current frame

+

+@item samples_n @emph{(audio only)}

+the number of samples in the current frame

+

+@item sample_rate @emph{(audio only)}

+the input sample rate

+

 @item key

 1 if the filtered frame is a key-frame, 0 otherwise

@@ -3582,7 +3591,7 @@ the frame is bottom-field-first

 the position in the file of the filtered frame, -1 if the information

 is not available (e.g. for synthetic video)

-@item scene

+@item scene @emph{(video only)}

 value between 0 and 1 to indicate a new scene; a low value reflects a low

 probability for the current frame to introduce a new scene, while a higher

 value means the current frame is more likely to be one (see the example below)

@@ -3617,6 +3626,9 @@ select='gte(t\,10)*lte(t\,20)*eq(pict_type\,I)'

 # select frames with a minimum distance of 10 seconds

 select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'

+

+# use aselect to select only audio frames with samples number > 100

+aselect='gt(samples_n\,100)'

 @end example

 Complete example to create a mosaic of the first scenes:

@@ -54,6 +54,7 @@ OBJS-$(CONFIG_AMERGE_FILTER)                 += af_amerge.o

 OBJS-$(CONFIG_AMIX_FILTER)                   += af_amix.o

 OBJS-$(CONFIG_ANULL_FILTER)                  += af_anull.o

 OBJS-$(CONFIG_ARESAMPLE_FILTER)              += af_aresample.o

+OBJS-$(CONFIG_ASELECT_FILTER)                += vf_select.o

 OBJS-$(CONFIG_ASENDCMD_FILTER)               += f_sendcmd.o

 OBJS-$(CONFIG_ASETNSAMPLES_FILTER)           += af_asetnsamples.o

 OBJS-$(CONFIG_ASETPTS_FILTER)                += f_setpts.o

@@ -46,6 +46,7 @@ void avfilter_register_all(void)

     REGISTER_FILTER (AMIX,        amix,        af);

     REGISTER_FILTER (ANULL,       anull,       af);

     REGISTER_FILTER (ARESAMPLE,   aresample,   af);

+    REGISTER_FILTER (ASELECT,     aselect,     af);

     REGISTER_FILTER (ASENDCMD,    asendcmd,    af);

     REGISTER_FILTER (ASETNSAMPLES, asetnsamples, af);

     REGISTER_FILTER (ASETPTS,     asetpts,     af);

@@ -29,8 +29,8 @@

 #include "libavutil/avutil.h"

 #define LIBAVFILTER_VERSION_MAJOR  3

-#define LIBAVFILTER_VERSION_MINOR  26

-#define LIBAVFILTER_VERSION_MICRO 102

+#define LIBAVFILTER_VERSION_MINOR  27

+#define LIBAVFILTER_VERSION_MICRO 100

 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

                                                LIBAVFILTER_VERSION_MINOR, \

@@ -27,6 +27,7 @@

 #include "libavutil/fifo.h"

 #include "libavutil/internal.h"

 #include "avfilter.h"

+#include "audio.h"

 #include "formats.h"

 #include "internal.h"

 #include "video.h"

@@ -62,6 +63,10 @@ static const char *const var_names[] = {

     "TOPFIRST",

     "BOTTOMFIRST",

+    "consumed_samples_n",///< number of samples consumed by the filter (only audio)

+    "samples_n",         ///< number of samples in the current frame (only audio)

+    "sample_rate",       ///< sample rate (only audio)

+

     "n",                 ///< frame number (starting from zero)

     "selected_n",        ///< selected frame number (starting from zero)

     "prev_selected_n",   ///< number of the last selected frame

@@ -101,6 +106,10 @@ enum var_name {

     VAR_INTERLACE_TYPE_T,

     VAR_INTERLACE_TYPE_B,

+    VAR_CONSUMED_SAMPLES_N,

+    VAR_SAMPLES_N,

+    VAR_SAMPLE_RATE,

+

     VAR_N,

     VAR_SELECTED_N,

     VAR_PREV_SELECTED_N,

@@ -174,6 +183,9 @@ static int config_input(AVFilterLink *inlink)

     select->var_values[VAR_INTERLACE_TYPE_T] = INTERLACE_TYPE_T;

     select->var_values[VAR_INTERLACE_TYPE_B] = INTERLACE_TYPE_B;

+    select->var_values[VAR_SAMPLE_RATE] =

+        inlink->type == AVMEDIA_TYPE_AUDIO ? inlink->sample_rate : NAN;

+

     if (CONFIG_AVCODEC && select->do_scene_detect) {

         select->avctx = avcodec_alloc_context3(NULL);

         if (!select->avctx)

@@ -231,13 +243,6 @@ static int select_frame(AVFilterContext *ctx, AVFilterBufferRef *picref)

     AVFilterLink *inlink = ctx->inputs[0];

     double res;

-    if (CONFIG_AVCODEC && select->do_scene_detect) {

-        char buf[32];

-        select->var_values[VAR_SCENE] = get_scene_score(ctx, picref);

-        // TODO: document metadata

-        snprintf(buf, sizeof(buf), "%f", select->var_values[VAR_SCENE]);

-        av_dict_set(&picref->metadata, "lavfi.scene_score", buf, 0);

-    }

     if (isnan(select->var_values[VAR_START_PTS]))

         select->var_values[VAR_START_PTS] = TS2D(picref->pts);

     if (isnan(select->var_values[VAR_START_T]))

@@ -248,34 +253,63 @@ static int select_frame(AVFilterContext *ctx, AVFilterBufferRef *picref)

     select->var_values[VAR_POS] = picref->pos == -1 ? NAN : picref->pos;

     select->var_values[VAR_PREV_PTS] = TS2D(picref ->pts);

-    select->var_values[VAR_INTERLACE_TYPE] =

-        !picref->video->interlaced     ? INTERLACE_TYPE_P :

+    switch (inlink->type) {

+    case AVMEDIA_TYPE_AUDIO:

+        select->var_values[VAR_SAMPLES_N] = picref->audio->nb_samples;

+        break;

+

+    case AVMEDIA_TYPE_VIDEO:

+        select->var_values[VAR_INTERLACE_TYPE] =

+            !picref->video->interlaced     ? INTERLACE_TYPE_P :

         picref->video->top_field_first ? INTERLACE_TYPE_T : INTERLACE_TYPE_B;

-    select->var_values[VAR_PICT_TYPE] = picref->video->pict_type;

+        select->var_values[VAR_PICT_TYPE] = picref->video->pict_type;

+        if (CONFIG_AVCODEC && select->do_scene_detect) {

+            char buf[32];

+            select->var_values[VAR_SCENE] = get_scene_score(ctx, picref);

+            // TODO: document metadata

+            snprintf(buf, sizeof(buf), "%f", select->var_values[VAR_SCENE]);

+            av_dict_set(&picref->metadata, "lavfi.scene_score", buf, 0);

+        }

+        break;

+    }

     res = av_expr_eval(select->expr, select->var_values, NULL);

     av_log(inlink->dst, AV_LOG_DEBUG,

-           "n:%d pts:%d t:%f pos:%d interlace_type:%c key:%d pict_type:%c "

-           "-> select:%f\n",

+           "n:%d pts:%d t:%f pos:%d key:%d",

            (int)select->var_values[VAR_N],

            (int)select->var_values[VAR_PTS],

            select->var_values[VAR_T],

            (int)select->var_values[VAR_POS],

-           select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_P ? 'P' :

-           select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_T ? 'T' :

-           select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_B ? 'B' : '?',

-           (int)select->var_values[VAR_KEY],

-           av_get_picture_type_char(select->var_values[VAR_PICT_TYPE]),

-           res);

+           (int)select->var_values[VAR_KEY]);

+

+    switch (inlink->type) {

+    case AVMEDIA_TYPE_VIDEO:

+        av_log(inlink->dst, AV_LOG_DEBUG, " interlace_type:%c pict_type:%c",

+               select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_P ? 'P' :

+               select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_T ? 'T' :

+               select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_B ? 'B' : '?',

+               av_get_picture_type_char(select->var_values[VAR_PICT_TYPE]));

+        break;

+    case AVMEDIA_TYPE_AUDIO:

+        av_log(inlink->dst, AV_LOG_DEBUG, " samples_n:%d consumed_samples_n:%d",

+               (int)select->var_values[VAR_SAMPLES_N],

+               (int)select->var_values[VAR_CONSUMED_SAMPLES_N]);

+        break;

+    }

-    select->var_values[VAR_N] += 1.0;

+    av_log(inlink->dst, AV_LOG_DEBUG, " -> select:%f\n", res);

     if (res) {

         select->var_values[VAR_PREV_SELECTED_N]   = select->var_values[VAR_N];

         select->var_values[VAR_PREV_SELECTED_PTS] = select->var_values[VAR_PTS];

         select->var_values[VAR_PREV_SELECTED_T]   = select->var_values[VAR_T];

         select->var_values[VAR_SELECTED_N] += 1.0;

+        if (inlink->type == AVMEDIA_TYPE_AUDIO)

+            select->var_values[VAR_CONSUMED_SAMPLES_N] += picref->audio->nb_samples;

     }

+

+    select->var_values[VAR_N] += 1.0;

+

     return res;

 }

@@ -339,6 +373,38 @@ static int query_formats(AVFilterContext *ctx)

     return 0;

 }

+#if CONFIG_ASELECT_FILTER

+static const AVFilterPad avfilter_af_aselect_inputs[] = {

+    {

+        .name             = "default",

+        .type             = AVMEDIA_TYPE_AUDIO,

+        .get_audio_buffer = ff_null_get_audio_buffer,

+        .config_props     = config_input,

+        .filter_frame     = filter_frame,

+    },

+    { NULL }

+};

+

+static const AVFilterPad avfilter_af_aselect_outputs[] = {

+    {

+        .name = "default",

+        .type = AVMEDIA_TYPE_AUDIO,

+    },

+    { NULL }

+};

+

+AVFilter avfilter_af_aselect = {

+    .name      = "aselect",

+    .description = NULL_IF_CONFIG_SMALL("Select audio frames to pass in output."),

+    .init      = init,

+    .uninit    = uninit,

+    .priv_size = sizeof(SelectContext),

+    .inputs    = avfilter_af_aselect_inputs,

+    .outputs   = avfilter_af_aselect_outputs,

+};

+#endif /* CONFIG_ASELECT_FILTER */

+

+#if CONFIG_SELECT_FILTER

 static const AVFilterPad avfilter_vf_select_inputs[] = {

     {

         .name             = "default",

@@ -362,7 +428,7 @@ static const AVFilterPad avfilter_vf_select_outputs[] = {

 AVFilter avfilter_vf_select = {

     .name      = "select",

-    .description = NULL_IF_CONFIG_SMALL("Select frames to pass in output."),

+    .description = NULL_IF_CONFIG_SMALL("Select video frames to pass in output."),

     .init      = init,

     .uninit    = uninit,

     .query_formats = query_formats,

@@ -372,3 +438,4 @@ AVFilter avfilter_vf_select = {

     .inputs    = avfilter_vf_select_inputs,

     .outputs   = avfilter_vf_select_outputs,

 };

+#endif /* CONFIG_SELECT_FILTER */