[FFmpeg-devel] [PATCH] lavfi: add aselect audio variant of select
Stefano Sabatini
stefasab at gmail.com
Tue Dec 11 23:22:56 CET 2012
TODO: add Changelog entry, bump minor
---
doc/filters.texi | 20 +++++++--
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_select.c | 106 +++++++++++++++++++++++++++++++++++++---------
4 files changed, 104 insertions(+), 24 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index b840cac..fefc2af 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3506,7 +3506,7 @@ scale='min(500\, iw*3/2):-1'
@end example
@end itemize
- at section select
+ at 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
- at item pict_type
+ at item pict_type @emph{(only video)}
the type of the filtered frame, can assume one of the following
values:
@table @option
@@ -3564,7 +3564,7 @@ values:
@item BI
@end table
- at item interlace_type
+ at item interlace_type @emph{(only video)}
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
+ at item consumed_sample_n @emph{(only audio)}
+the number of selected samples before the current frame
+
+ at item samples_n @emph{(only audio)}
+the number of samples in the current frame
+
+ at item sample_rate @emph{(only audio)}
+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)
- at item scene
+ at item scene @emph{(only video)}
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:
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 191e3e1..3480b42 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -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
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index ffde5ce..8c8f1fc 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -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);
diff --git a/libavfilter/vf_select.c b/libavfilter/vf_select.c
index c965387..e68179e 100644
--- a/libavfilter/vf_select.c
+++ b/libavfilter/vf_select.c
@@ -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 +253,62 @@ 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;
+ select->var_values[VAR_CONSUMED_SAMPLES_N] += picref->audio->nb_samples;
}
+
+ select->var_values[VAR_N] += 1.0;
+
return res;
}
@@ -339,6 +372,38 @@ 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 +427,7 @@ 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 +437,4 @@ AVFilter avfilter_vf_select = {
.inputs = avfilter_vf_select_inputs,
.outputs = avfilter_vf_select_outputs,
};
+#endif /* CONFIG_SELECT_FILTER */
--
1.7.9.5
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