lavfi: add interleave filters

Changelog

@@ -29,6 +29,7 @@ version <next>:
   become the default at the next libavformat major bump.
 - decent native animated GIF encoding
 - asetrate filter
+- interleave filter
 
 
 version 1.2:

doc/filters.texi

@@ -7475,6 +7475,54 @@ do not have exactly the same duration in the first file.
 
 @end itemize
 
+@section interleave, ainterleave
+
+Temporally interleave frames from several inputs.
+
+@code{interleave} works with video inputs, @code{ainterleave} with audio.
+
+These filters read frames from several inputs and send the oldest
+queued frame to the output.
+
+Input streams must have a well defined, monotonically increasing frame
+timestamp values.
+
+In order to submit one frame to output, these filters need to enqueue
+at least one frame for each input, so they cannot work in case one
+input is not yet terminated and will not receive incoming frames.
+
+For example consider the case when one input is a @code{select} filter
+which always drop input frames. The @code{interleave} filter will keep
+reading from that input, but it will never be able to send new frames
+to output until the input will send an end-of-stream signal.
+
+Also, depending on inputs synchronization, the filters will drop
+frames in case one input receives more frames than the other ones, and
+the queue is already filled.
+
+These filters accept the following options:
+
+@table @option
+@item nb_inputs, n
+Set the number of different inputs, it is 2 by default.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Interleave frames belonging to different streams using @command{ffmpeg}:
+@example
+ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
+@end example
+
+@item
+Add flickering blur effect:
+@example
+select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
+@end example
+@end itemize
+
 @section showspectrum
 
 Convert input audio to a video output, representing the audio frequency

libavfilter/Makefile

@@ -52,6 +52,7 @@ OBJS-$(CONFIG_SWSCALE)                       += lswsutils.o
 OBJS-$(CONFIG_ACONVERT_FILTER)               += af_aconvert.o
 OBJS-$(CONFIG_AFADE_FILTER)                  += af_afade.o
 OBJS-$(CONFIG_AFORMAT_FILTER)                += af_aformat.o
+OBJS-$(CONFIG_AINTERLEAVE_FILTER)            += f_interleave.o
 OBJS-$(CONFIG_ALLPASS_FILTER)                += af_biquads.o
 OBJS-$(CONFIG_AMERGE_FILTER)                 += af_amerge.o
 OBJS-$(CONFIG_AMIX_FILTER)                   += af_amix.o
@@ -136,6 +137,7 @@ OBJS-$(CONFIG_HUE_FILTER)                    += vf_hue.o
 OBJS-$(CONFIG_IDET_FILTER)                   += vf_idet.o
 OBJS-$(CONFIG_IL_FILTER)                     += vf_il.o
 OBJS-$(CONFIG_INTERLACE_FILTER)              += vf_interlace.o
+OBJS-$(CONFIG_INTERLEAVE_FILTER)             += f_interleave.o
 OBJS-$(CONFIG_KERNDEINT_FILTER)              += vf_kerndeint.o
 OBJS-$(CONFIG_LUT_FILTER)                    += vf_lut.o
 OBJS-$(CONFIG_LUTRGB_FILTER)                 += vf_lut.o

libavfilter/allfilters.c

@@ -50,6 +50,7 @@ void avfilter_register_all(void)
 #endif
     REGISTER_FILTER(AFADE,          afade,          af);
     REGISTER_FILTER(AFORMAT,        aformat,        af);
+    REGISTER_FILTER(AINTERLEAVE,    ainterleave,    af);
     REGISTER_FILTER(ALLPASS,        allpass,        af);
     REGISTER_FILTER(AMERGE,         amerge,         af);
     REGISTER_FILTER(AMIX,           amix,           af);
@@ -134,6 +135,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(IDET,           idet,           vf);
     REGISTER_FILTER(IL,             il,             vf);
     REGISTER_FILTER(INTERLACE,      interlace,      vf);
+    REGISTER_FILTER(INTERLEAVE,     interleave,     vf);
     REGISTER_FILTER(KERNDEINT,      kerndeint,      vf);
     REGISTER_FILTER(LUT,            lut,            vf);
     REGISTER_FILTER(LUTRGB,         lutrgb,         vf);

libavfilter/f_interleave.c

+/*
+ * Copyright (c) 2013 Stefano Sabatini
+ *
+ * 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
+ * audio and video interleaver
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "bufferqueue.h"
+#include "formats.h"
+#include "internal.h"
+#include "audio.h"
+#include "video.h"
+
+typedef struct {
+    const AVClass *class;
+    int nb_inputs;
+    struct FFBufQueue *queues;
+} InterleaveContext;
+
+#define OFFSET(x) offsetof(InterleaveContext, x)
+
+#define DEFINE_OPTIONS(filt_name, flags_)                           \
+static const AVOption filt_name##_options[] = {                     \
+   { "nb_inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64 = 2}, 1, INT_MAX, .flags = flags_ }, \
+   { "n",         "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64 = 2}, 1, INT_MAX, .flags = flags_ }, \
+   { NULL },                                                        \
+}
+
+inline static int push_frame(AVFilterContext *ctx)
+{
+    InterleaveContext *interleave = ctx->priv;
+    AVFrame *frame;
+    int i, queue_idx = -1;
+    int64_t pts_min = INT64_MAX;
+
+    /* look for oldest frame */
+    for (i = 0; i < ctx->nb_inputs; i++) {
+        struct FFBufQueue *q = &interleave->queues[i];
+
+        if (!q->available && !ctx->inputs[i]->closed)
+            return 0;
+        if (q->available) {
+            frame = ff_bufqueue_peek(q, 0);
+            if (frame->pts < pts_min) {
+                pts_min = frame->pts;
+                queue_idx = i;
+            }
+        }
+    }
+
+    /* all inputs are closed */
+    if (queue_idx < 0)
+        return AVERROR_EOF;
+
+    frame = ff_bufqueue_get(&interleave->queues[queue_idx]);
+    av_log(ctx, AV_LOG_DEBUG, "queue:%d -> frame time:%f\n",
+           queue_idx, frame->pts * av_q2d(AV_TIME_BASE_Q));
+    return ff_filter_frame(ctx->outputs[0], frame);
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+    AVFilterContext *ctx = inlink->dst;
+    InterleaveContext *interleave = ctx->priv;
+    unsigned in_no = FF_INLINK_IDX(inlink);
+
+    if (frame->pts == AV_NOPTS_VALUE) {
+        av_log(ctx, AV_LOG_WARNING,
+               "NOPTS value for input frame cannot be accepted, frame discarded\n");
+        av_frame_free(&frame);
+        return AVERROR_INVALIDDATA;
+    }
+
+    /* queue frame */
+    frame->pts = av_rescale_q(frame->pts, inlink->time_base, AV_TIME_BASE_Q);
+    av_log(ctx, AV_LOG_DEBUG, "frame pts:%f -> queue idx:%d available:%d\n",
+           frame->pts * av_q2d(AV_TIME_BASE_Q), in_no, interleave->queues[in_no].available);
+    ff_bufqueue_add(ctx, &interleave->queues[in_no], frame);
+
+    return push_frame(ctx);
+}
+
+static int init(AVFilterContext *ctx)
+{
+    InterleaveContext *interleave = ctx->priv;
+    const AVFilterPad *outpad = &ctx->filter->outputs[0];
+    int i;
+
+    interleave->queues = av_calloc(interleave->nb_inputs, sizeof(interleave->queues[0]));
+    if (!interleave->queues)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < interleave->nb_inputs; i++) {
+        AVFilterPad inpad = { 0 };
+
+        inpad.name = av_asprintf("input%d", i);
+        if (!inpad.name)
+            return AVERROR(ENOMEM);
+        inpad.type         = outpad->type;
+        inpad.filter_frame = filter_frame;
+
+        switch (outpad->type) {
+        case AVMEDIA_TYPE_VIDEO:
+            inpad.get_video_buffer = ff_null_get_video_buffer; break;
+        case AVMEDIA_TYPE_AUDIO:
+            inpad.get_audio_buffer = ff_null_get_audio_buffer; break;
+        default:
+            av_assert0(0);
+        }
+        ff_insert_inpad(ctx, i, &inpad);
+    }
+
+    return 0;
+}
+
+static void uninit(AVFilterContext *ctx)
+{
+    InterleaveContext *interleave = ctx->priv;
+    int i;
+
+    for (i = 0; i < ctx->nb_inputs; i++) {
+        ff_bufqueue_discard_all(&interleave->queues[i]);
+        av_freep(&interleave->queues[i]);
+        av_freep(&ctx->input_pads[i].name);
+    }
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    AVFilterLink *inlink0 = ctx->inputs[0];
+    int i;
+
+    if (outlink->type == AVMEDIA_TYPE_VIDEO) {
+        outlink->time_base           = AV_TIME_BASE_Q;
+        outlink->w                   = inlink0->w;
+        outlink->h                   = inlink0->h;
+        outlink->sample_aspect_ratio = inlink0->sample_aspect_ratio;
+        outlink->format              = inlink0->format;
+        outlink->frame_rate = (AVRational) {1, 0};
+        for (i = 1; i < ctx->nb_inputs; i++) {
+            AVFilterLink *inlink = ctx->inputs[i];
+
+            if (outlink->w                       != inlink->w                       ||
+                outlink->h                       != inlink->h                       ||
+                outlink->sample_aspect_ratio.num != inlink->sample_aspect_ratio.num ||
+                outlink->sample_aspect_ratio.den != inlink->sample_aspect_ratio.den) {
+                av_log(ctx, AV_LOG_ERROR, "Parameters for input link %s "
+                       "(size %dx%d, SAR %d:%d) do not match the corresponding "
+                       "output link parameters (%dx%d, SAR %d:%d)\n",
+                       ctx->input_pads[i].name, inlink->w, inlink->h,
+                       inlink->sample_aspect_ratio.num,
+                       inlink->sample_aspect_ratio.den,
+                       outlink->w, outlink->h,
+                       outlink->sample_aspect_ratio.num,
+                       outlink->sample_aspect_ratio.den);
+                return AVERROR(EINVAL);
+            }
+        }
+    }
+
+    outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
+    return 0;
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    InterleaveContext *interleave = ctx->priv;
+    int i, ret;
+
+    for (i = 0; i < ctx->nb_inputs; i++) {
+        if (!interleave->queues[i].available && !ctx->inputs[i]->closed) {
+            ret = ff_request_frame(ctx->inputs[i]);
+            if (ret != AVERROR_EOF)
+                return ret;
+        }
+    }
+
+    return push_frame(ctx);
+}
+
+#if CONFIG_INTERLEAVE_FILTER
+
+DEFINE_OPTIONS(interleave, AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM);
+AVFILTER_DEFINE_CLASS(interleave);
+
+static const AVFilterPad interleave_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+        .request_frame = request_frame,
+    },
+    { NULL }
+};
+
+AVFilter avfilter_vf_interleave = {
+    .name        = "interleave",
+    .description = NULL_IF_CONFIG_SMALL("Temporally interleave video inputs."),
+    .priv_size   = sizeof(InterleaveContext),
+    .init        = init,
+    .uninit      = uninit,
+    .outputs     = interleave_outputs,
+    .priv_class  = &interleave_class,
+    .flags       = AVFILTER_FLAG_DYNAMIC_INPUTS,
+};
+
+#endif
+
+#if CONFIG_AINTERLEAVE_FILTER
+
+DEFINE_OPTIONS(ainterleave, AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM);
+AVFILTER_DEFINE_CLASS(ainterleave);
+
+static const AVFilterPad ainterleave_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_AUDIO,
+        .config_props  = config_output,
+        .request_frame = request_frame,
+    },
+    { NULL }
+};
+
+AVFilter avfilter_af_ainterleave = {
+    .name        = "ainterleave",
+    .description = NULL_IF_CONFIG_SMALL("Temporally interleave audio inputs."),
+    .priv_size   = sizeof(InterleaveContext),
+    .init        = init,
+    .uninit      = uninit,
+    .outputs     = ainterleave_outputs,
+    .priv_class  = &ainterleave_class,
+    .flags       = AVFILTER_FLAG_DYNAMIC_INPUTS,
+};
+
+#endif

libavfilter/version.h

@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  59
+#define LIBAVFILTER_VERSION_MINOR  60
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \