@@ -34,6 +34,9 @@

 #include "libavutil/rational.h"

 #include "libavutil/samplefmt.h"

+#define FF_INTERNAL_FIELDS 1

+#include "framequeue.h"

+

 #include "audio.h"

 #include "avfilter.h"

 #include "formats.h"

@@ -135,6 +138,10 @@ int avfilter_link(AVFilterContext *src, unsigned srcpad,

 {

     AVFilterLink *link;

+    av_assert0(src->graph);

+    av_assert0(dst->graph);

+    av_assert0(src->graph == dst->graph);

+

     if (src->nb_outputs <= srcpad || dst->nb_inputs <= dstpad ||

         src->outputs[srcpad]      || dst->inputs[dstpad])

         return AVERROR(EINVAL);

@@ -160,6 +167,7 @@ int avfilter_link(AVFilterContext *src, unsigned srcpad,

     link->type    = src->output_pads[srcpad].type;

     av_assert0(AV_PIX_FMT_NONE == -1 && AV_SAMPLE_FMT_NONE == -1);

     link->format  = -1;

+    ff_framequeue_init(&link->fifo, &src->graph->internal->frame_queues);

     return 0;

 }

@@ -170,6 +178,7 @@ void avfilter_link_free(AVFilterLink **link)

         return;

     av_frame_free(&(*link)->partial_buf);

+    ff_framequeue_free(&(*link)->fifo);

     ff_video_frame_pool_uninit((FFVideoFramePool**)&(*link)->video_frame_pool);

     av_freep(link);

@@ -180,16 +189,46 @@ int avfilter_link_get_channels(AVFilterLink *link)

     return link->channels;

 }

+static void ff_filter_set_ready(AVFilterContext *filter, unsigned priority)

+{

+    filter->ready = FFMAX(filter->ready, priority);

+}

+

+/**

+ * Clear frame_blocked_in on all outputs.

+ * This is necessary whenever something changes on input.

+ */

+static void filter_unblock(AVFilterContext *filter)

+{

+    unsigned i;

+

+    for (i = 0; i < filter->nb_outputs; i++)

+        filter->outputs[i]->frame_blocked_in = 0;

+}

+

+

 void ff_avfilter_link_set_in_status(AVFilterLink *link, int status, int64_t pts)

 {

-    ff_avfilter_link_set_out_status(link, status, pts);

+    if (link->status_in == status)

+        return;

+    av_assert0(!link->status_in);

+    link->status_in = status;

+    link->status_in_pts = pts;

+    link->frame_wanted_out = 0;

+    link->frame_blocked_in = 0;

+    filter_unblock(link->dst);

+    ff_filter_set_ready(link->dst, 200);

 }

 void ff_avfilter_link_set_out_status(AVFilterLink *link, int status, int64_t pts)

 {

-    link->status = status;

-    link->frame_wanted_in = link->frame_wanted_out = 0;

-    ff_update_link_current_pts(link, pts);

+    av_assert0(!link->frame_wanted_out);

+    av_assert0(!link->status_out);

+    link->status_out = status;

+    if (pts != AV_NOPTS_VALUE)

+        ff_update_link_current_pts(link, pts);

+    filter_unblock(link->dst);

+    ff_filter_set_ready(link->src, 200);

 }

 void avfilter_link_set_closed(AVFilterLink *link, int closed)

@@ -370,10 +409,23 @@ int ff_request_frame(AVFilterLink *link)

 {

     FF_TPRINTF_START(NULL, request_frame); ff_tlog_link(NULL, link, 1);

-    if (link->status)

-        return link->status;

-    link->frame_wanted_in = 1;

+    if (link->status_out)

+        return link->status_out;

+    if (link->status_in) {

+        if (ff_framequeue_queued_frames(&link->fifo)) {

+            av_assert1(!link->frame_wanted_out);

+            av_assert1(link->dst->ready >= 300);

+            return 0;

+        } else {

+            /* Acknowledge status change. Filters using ff_request_frame() will

+               handle the change automatically. Filters can also check the

+               status directly but none do yet. */

+            ff_avfilter_link_set_out_status(link, link->status_in, link->status_in_pts);

+            return link->status_out;

+        }

+    }

     link->frame_wanted_out = 1;

+    ff_filter_set_ready(link->src, 100);

     return 0;

 }

@@ -382,22 +434,17 @@ int ff_request_frame_to_filter(AVFilterLink *link)

     int ret = -1;

     FF_TPRINTF_START(NULL, request_frame_to_filter); ff_tlog_link(NULL, link, 1);

-    link->frame_wanted_in = 0;

+    /* Assume the filter is blocked, let the method clear it if not */

+    link->frame_blocked_in = 1;

     if (link->srcpad->request_frame)

         ret = link->srcpad->request_frame(link);

     else if (link->src->inputs[0])

         ret = ff_request_frame(link->src->inputs[0]);

-    if (ret == AVERROR_EOF && link->partial_buf) {

-        AVFrame *pbuf = link->partial_buf;

-        link->partial_buf = NULL;

-        ret = ff_filter_frame_framed(link, pbuf);

-        ff_avfilter_link_set_in_status(link, AVERROR_EOF, AV_NOPTS_VALUE);

-        link->frame_wanted_out = 0;

-        return ret;

-    }

     if (ret < 0) {

-        if (ret != AVERROR(EAGAIN) && ret != link->status)

+        if (ret != AVERROR(EAGAIN) && ret != link->status_in)

             ff_avfilter_link_set_in_status(link, ret, AV_NOPTS_VALUE);

+        if (ret == AVERROR_EOF)

+            ret = 0;

     }

     return ret;

 }

@@ -1056,11 +1103,6 @@ static int ff_filter_frame_framed(AVFilterLink *link, AVFrame *frame)

     AVFilterCommand *cmd= link->dst->command_queue;

     int64_t pts;

-    if (link->status) {

-        av_frame_free(&frame);

-        return link->status;

-    }

-

     if (!(filter_frame = dst->filter_frame))

         filter_frame = default_filter_frame;

@@ -1142,52 +1184,9 @@ fail:

     return ret;

 }

-static int ff_filter_frame_needs_framing(AVFilterLink *link, AVFrame *frame)

-{

-    int insamples = frame->nb_samples, inpos = 0, nb_samples;

-    AVFrame *pbuf = link->partial_buf;

-    int nb_channels = av_frame_get_channels(frame);

-    int ret = 0;

-

-    /* Handle framing (min_samples, max_samples) */

-    while (insamples) {

-        if (!pbuf) {

-            AVRational samples_tb = { 1, link->sample_rate };

-            pbuf = ff_get_audio_buffer(link, link->partial_buf_size);

-            if (!pbuf) {

-                av_log(link->dst, AV_LOG_WARNING,

-                       "Samples dropped due to memory allocation failure.\n");

-                return 0;

-            }

-            av_frame_copy_props(pbuf, frame);

-            pbuf->pts = frame->pts;

-            if (pbuf->pts != AV_NOPTS_VALUE)

-                pbuf->pts += av_rescale_q(inpos, samples_tb, link->time_base);

-            pbuf->nb_samples = 0;

-        }

-        nb_samples = FFMIN(insamples,

-                           link->partial_buf_size - pbuf->nb_samples);

-        av_samples_copy(pbuf->extended_data, frame->extended_data,

-                        pbuf->nb_samples, inpos,

-                        nb_samples, nb_channels, link->format);

-        inpos                   += nb_samples;

-        insamples               -= nb_samples;

-        pbuf->nb_samples += nb_samples;

-        if (pbuf->nb_samples >= link->min_samples) {

-            ret = ff_filter_frame_framed(link, pbuf);

-            pbuf = NULL;

-        } else {

-            if (link->frame_wanted_out)

-                link->frame_wanted_in = 1;

-        }

-    }

-    av_frame_free(&frame);

-    link->partial_buf = pbuf;

-    return ret;

-}

-

 int ff_filter_frame(AVFilterLink *link, AVFrame *frame)

 {

+    int ret;

     FF_TPRINTF_START(NULL, filter_frame); ff_tlog_link(NULL, link, 1); ff_tlog(NULL, " "); ff_tlog_ref(NULL, frame, 1);

     /* Consistency checks */

@@ -1220,23 +1219,329 @@ int ff_filter_frame(AVFilterLink *link, AVFrame *frame)

         }

     }

-    link->frame_wanted_out = 0;

+    link->frame_blocked_in = link->frame_wanted_out = 0;

     link->frame_count_in++;

-    /* Go directly to actual filtering if possible */

-    if (link->type == AVMEDIA_TYPE_AUDIO &&

-        link->min_samples &&

-        (link->partial_buf ||

-         frame->nb_samples < link->min_samples ||

-         frame->nb_samples > link->max_samples)) {

-        return ff_filter_frame_needs_framing(link, frame);

-    } else {

-        return ff_filter_frame_framed(link, frame);

+    filter_unblock(link->dst);

+    ret = ff_framequeue_add(&link->fifo, frame);

+    if (ret < 0) {

+        av_frame_free(&frame);

+        return ret;

     }

+    ff_filter_set_ready(link->dst, 300);

+    return 0;

+

 error:

     av_frame_free(&frame);

     return AVERROR_PATCHWELCOME;

 }

+static int samples_ready(AVFilterLink *link)

+{

+    return ff_framequeue_queued_frames(&link->fifo) &&

+           (ff_framequeue_queued_samples(&link->fifo) >= link->min_samples ||

+            link->status_in);

+}

+

+static int take_samples(AVFilterLink *link, unsigned min, unsigned max,

+                        AVFrame **rframe)

+{

+    AVFrame *frame0, *frame, *buf;

+    unsigned nb_samples, nb_frames, i, p;

+    int ret;

+

+    /* Note: this function relies on no format changes and must only be

+       called with enough samples. */

+    av_assert1(samples_ready(link));

+    frame0 = frame = ff_framequeue_peek(&link->fifo, 0);

+    if (frame->nb_samples >= min && frame->nb_samples < max) {

+        *rframe = ff_framequeue_take(&link->fifo);

+        return 0;

+    }

+    nb_frames = 0;

+    nb_samples = 0;

+    while (1) {

+        if (nb_samples + frame->nb_samples > max) {

+            if (nb_samples < min)

+                nb_samples = max;

+            break;

+        }

+        nb_samples += frame->nb_samples;

+        nb_frames++;

+        if (nb_frames == ff_framequeue_queued_frames(&link->fifo))

+            break;

+        frame = ff_framequeue_peek(&link->fifo, nb_frames);

+    }

+

+    buf = ff_get_audio_buffer(link, nb_samples);

+    if (!buf)

+        return AVERROR(ENOMEM);

+    ret = av_frame_copy_props(buf, frame0);

+    if (ret < 0) {

+        av_frame_free(&buf);

+        return ret;

+    }

+    buf->pts = frame0->pts;

+

+    p = 0;

+    for (i = 0; i < nb_frames; i++) {

+        frame = ff_framequeue_take(&link->fifo);

+        av_samples_copy(buf->extended_data, frame->extended_data, p, 0,

+                        frame->nb_samples, link->channels, link->format);

+        p += frame->nb_samples;

+    }

+    if (p < nb_samples) {

+        unsigned n = nb_samples - p;

+        frame = ff_framequeue_peek(&link->fifo, 0);

+        av_samples_copy(buf->extended_data, frame->extended_data, p, 0, n,

+                        link->channels, link->format);

+        frame->nb_samples -= n;

+        av_samples_copy(frame->extended_data, frame->extended_data, 0, n,

+                        frame->nb_samples, link->channels, link->format);

+        if (frame->pts != AV_NOPTS_VALUE)

+            frame->pts += av_rescale_q(n, av_make_q(1, link->sample_rate), link->time_base);

+        ff_framequeue_update_peeked(&link->fifo, 0);

+        ff_framequeue_skip_samples(&link->fifo, n);

+    }

+

+    *rframe = buf;

+    return 0;

+}

+

+int ff_filter_frame_to_filter(AVFilterLink *link)

+{

+    AVFrame *frame;

+    AVFilterContext *dst = link->dst;

+    int ret;

+

+    av_assert1(ff_framequeue_queued_frames(&link->fifo));

+    if (link->min_samples) {

+        int min = link->min_samples;

+        if (link->status_in)

+            min = FFMIN(min, ff_framequeue_queued_samples(&link->fifo));

+        ret = take_samples(link, min, link->max_samples, &frame);

+        if (ret < 0)

+            return ret;

+    } else {

+        frame = ff_framequeue_take(&link->fifo);

+    }

+    /* The filter will soon have received a new frame, that may allow it to

+       produce one or more: unblock its outputs. */

+    filter_unblock(dst);

+    ret = ff_filter_frame_framed(link, frame);

+    if (ret < 0 && ret != link->status_out) {

+        ff_avfilter_link_set_out_status(link, ret, AV_NOPTS_VALUE);

+    } else {

+        /* Run once again, to see if several frames were available, or if

+           the input status has also changed, or any other reason. */

+        ff_filter_set_ready(dst, 300);

+    }

+    return ret;

+}

+

+static int forward_status_change(AVFilterContext *filter, AVFilterLink *in)

+{

+    unsigned out = 0, progress = 0;

+    int ret;

+

+    av_assert0(!in->status_out);

+    if (!filter->nb_outputs) {

+        /* not necessary with the current API and sinks */

+        return 0;

+    }

+    while (!in->status_out) {

+        if (!filter->outputs[out]->status_in) {

+            progress++;

+            ret = ff_request_frame_to_filter(filter->outputs[out]);

+            if (ret < 0)

+                return ret;

+        }

+        if (++out == filter->nb_outputs) {

+            if (!progress) {

+                /* Every output already closed: input no longer interesting

+                   (example: overlay in shortest mode, other input closed). */

+                ff_avfilter_link_set_out_status(in, in->status_in, in->status_in_pts);

+                return 0;

+            }

+            progress = 0;

+            out = 0;

+        }

+    }

+    ff_filter_set_ready(filter, 200);

+    return 0;

+}

+

+#define FFERROR_NOT_READY FFERRTAG('N','R','D','Y')

+

+static int ff_filter_activate_default(AVFilterContext *filter)

+{

+    unsigned i;

+

+    for (i = 0; i < filter->nb_inputs; i++) {

+        if (samples_ready(filter->inputs[i])) {

+            return ff_filter_frame_to_filter(filter->inputs[i]);

+        }

+    }

+    for (i = 0; i < filter->nb_inputs; i++) {

+        if (filter->inputs[i]->status_in && !filter->inputs[i]->status_out) {

+            av_assert1(!ff_framequeue_queued_frames(&filter->inputs[i]->fifo));

+            return forward_status_change(filter, filter->inputs[i]);

+        }

+    }

+    for (i = 0; i < filter->nb_outputs; i++) {

+        if (filter->outputs[i]->frame_wanted_out &&

+            !filter->outputs[i]->frame_blocked_in) {

+            return ff_request_frame_to_filter(filter->outputs[i]);

+        }

+    }

+    return FFERROR_NOT_READY;

+}

+

+/*

+   Filter scheduling and activation

+

+   When a filter is activated, it must:

+   - if possible, output a frame;

+   - else, if relevant, forward the input status change;

+   - else, check outputs for wanted frames and forward the requests.

+

+   The following AVFilterLink fields are used for activation:

+

+   - frame_wanted_out:

+

+     This field indicates if a frame is needed on this input of the

+     destination filter. A positive value indicates that a frame is needed

+     to process queued frames or internal data or to satisfy the

+     application; a zero value indicates that a frame is not especially

+     needed but could be processed anyway; a negative value indicates that a

+     frame would just be queued.

+

+     It is set by filters using ff_request_frame() or ff_request_no_frame(),

+     when requested by the application through a specific API or when it is

+     set on one of the outputs.

+

+     It is cleared when a frame is sent from the source using

+     ff_filter_frame().

+

+     It is also cleared when a status change is sent from the source using

+     ff_avfilter_link_set_in_status().

+

+   - frame_blocked_in:

+

+     This field means that the source filter can not generate a frame as is.

+     Its goal is to avoid repeatedly calling the request_frame() method on

+     the same link.

+

+     It is set by the framework on all outputs of a filter before activating it.

+

+     It is automatically cleared by ff_filter_frame().

+

+     It is also automatically cleared by ff_avfilter_link_set_in_status().

+

+     It is also cleared on all outputs (using filter_unblock()) when

+     something happens on an input: processing a frame or changing the

+     status.

+

+   - fifo:

+

+     Contains the frames queued on a filter input. If it contains frames and

+     frame_wanted_out is not set, then the filter can be activated. If that

+     result in the filter not able to use these frames, the filter must set

+     frame_wanted_out to ask for more frames.

+

+   - status_in and status_in_pts:

+

+     Status (EOF or error code) of the link and timestamp of the status

+     change (in link time base, same as frames) as seen from the input of

+     the link. The status change is considered happening after the frames

+     queued in fifo.

+

+     It is set by the source filter using ff_avfilter_link_set_in_status().

+

+   - status_out:

+

+     Status of the link as seen from the output of the link. The status

+     change is considered having already happened.

+

+     It is set by the destination filter using

+     ff_avfilter_link_set_out_status().

+

+   Filters are activated according to the ready field, set using the

+   ff_filter_set_ready(). Eventually, a priority queue will be used.

+   ff_filter_set_ready() is called whenever anything could cause progress to

+   be possible. Marking a filter ready when it is not is not a problem,

+   except for the small overhead it causes.

+

+   Conditions that cause a filter to be marked ready are:

+

+   - frames added on an input link;

+

+   - changes in the input or output status of an input link;

+

+   - requests for a frame on an output link;

+

+   - after any actual processing using the legacy methods (filter_frame(),

+     and request_frame() to acknowledge status changes), to run once more

+     and check if enough input was present for several frames.

+

+   Exemples of scenarios to consider:

+

+   - buffersrc: activate if frame_wanted_out to notify the application;

+     activate when the application adds a frame to push it immediately.

+

+   - testsrc: activate only if frame_wanted_out to produce and push a frame.

+

+   - concat (not at stitch points): can process a frame on any output.

+     Activate if frame_wanted_out on output to forward on the corresponding

+     input. Activate when a frame is present on input to process it

+     immediately.

+

+   - framesync: needs at least one frame on each input; extra frames on the

+     wrong input will accumulate. When a frame is first added on one input,

+     set frame_wanted_out<0 on it to avoid getting more (would trigger

+     testsrc) and frame_wanted_out>0 on the other to allow processing it.

+

+   Activation of old filters:

+

+   In order to activate a filter implementing the legacy filter_frame() and

+   request_frame() methods, perform the first possible of the following

+   actions:

+

+   - If an input has frames in fifo and frame_wanted_out == 0, dequeue a

+     frame and call filter_frame().

+

+     Ratinale: filter frames as soon as possible instead of leaving them

+     queued; frame_wanted_out < 0 is not possible since the old API does not

+     set it nor provides any similar feedback; frame_wanted_out > 0 happens

+     when min_samples > 0 and there are not enough samples queued.

+

+   - If an input has status_in set but not status_out, try to call

+     request_frame() on one of the outputs in the hope that it will trigger

+     request_frame() on the input with status_in and acknowledge it. This is

+     awkward and fragile, filters with several inputs or outputs should be

+     updated to direct activation as soon as possible.

+

+   - If an output has frame_wanted_out > 0 and not frame_blocked_in, call

+     request_frame().

+

+     Rationale: checking frame_blocked_in is necessary to avoid requesting

+     repeatedly on a blocked input if another is not blocked (example:

+     [buffersrc1][testsrc1][buffersrc2][testsrc2]concat=v=2).

+

+     TODO: respect needs_fifo and remove auto-inserted fifos.

+

+ */

+

+int ff_filter_activate(AVFilterContext *filter)

+{

+    int ret;

+

+    filter->ready = 0;

+    ret = ff_filter_activate_default(filter);

+    if (ret == FFERROR_NOT_READY)

+        ret = 0;

+    return ret;

+}

+

 const AVClass *avfilter_get_class(void)

 {

     return &avfilter_class;

@@ -368,6 +368,13 @@ struct AVFilterContext {

      * Overrides global number of threads set per filter graph.

      */

     int nb_threads;

+

+    /**

+     * Ready status of the filter.

+     * A non-0 value means that the filter needs activating;

+     * a higher value suggests a more urgent activation.

+     */

+    unsigned ready;

 };

 /**

@@ -509,18 +516,6 @@ struct AVFilterLink {

     int max_samples;

     /**

-     * Link status.

-     * If not zero, all attempts of filter_frame or request_frame

-     * will fail with the corresponding code, and if necessary the reference

-     * will be destroyed.

-     * If request_frame returns an error, the status is set on the

-     * corresponding link.

-     * It can be set also be set by either the source or the destination

-     * filter.

-     */

-    int status;

-

-    /**

      * Number of channels.

      */

     int channels;

@@ -541,13 +536,6 @@ struct AVFilterLink {

     void *video_frame_pool;

     /**

-     * True if a frame is currently wanted on the input of this filter.

-     * Set when ff_request_frame() is called by the output,

-     * cleared when the request is handled or forwarded.

-     */

-    int frame_wanted_in;

-

-    /**

      * True if a frame is currently wanted on the output of this filter.

      * Set when ff_request_frame() is called by the output,

      * cleared when a frame is filtered.

@@ -559,6 +547,51 @@ struct AVFilterLink {

      * AVHWFramesContext describing the frames.

      */

     AVBufferRef *hw_frames_ctx;

+

+#ifndef FF_INTERNAL_FIELDS

+

+    /**

+     * Internal structure members.

+     * The fields below this limit are internal for libavfilter's use

+     * and must in no way be accessed by applications.

+     */

+    char reserved[0xF000];

+

+#else /* FF_INTERNAL_FIELDS */

+

+    /**

+     * Queue of frames waiting to be filtered.

+     */

+    FFFrameQueue fifo;

+

+    /**

+     * If set, the source filter can not generate a frame as is.

+     * The goal is to avoid repeatedly calling the request_frame() method on

+     * the same link.

+     */

+    int frame_blocked_in;

+

+    /**

+     * Link input status.

+     * If not zero, all attempts of filter_frame will fail with the

+     * corresponding code.

+     */

+    int status_in;

+

+    /**

+     * Timestamp of the input status change.

+     */

+    int64_t status_in_pts;

+

+    /**

+     * Link output status.

+     * If not zero, all attempts of request_frame will fail with the

+     * corresponding code.

+     */

+    int status_out;

+

+#endif /* FF_INTERNAL_FIELDS */

+

 };

 /**

@@ -32,6 +32,9 @@

 #include "libavutil/opt.h"

 #include "libavutil/pixdesc.h"

+#define FF_INTERNAL_FIELDS 1

+#include "framequeue.h"

+

 #include "avfilter.h"

 #include "formats.h"

 #include "internal.h"

@@ -87,6 +90,7 @@ AVFilterGraph *avfilter_graph_alloc(void)

     ret->av_class = &filtergraph_class;

     av_opt_set_defaults(ret);

+    ff_framequeue_global_init(&ret->internal->frame_queues);

     return ret;

 }

@@ -1377,10 +1381,10 @@ void ff_avfilter_graph_update_heap(AVFilterGraph *graph, AVFilterLink *link)

     heap_bubble_down(graph, link, link->age_index);

 }

-

 int avfilter_graph_request_oldest(AVFilterGraph *graph)

 {

     AVFilterLink *oldest = graph->sink_links[0];

+    int64_t frame_count;

     int r;

     while (graph->sink_links_count) {

@@ -1400,7 +1404,8 @@ int avfilter_graph_request_oldest(AVFilterGraph *graph)

     if (!graph->sink_links_count)

         return AVERROR_EOF;

     av_assert1(oldest->age_index >= 0);

-    while (oldest->frame_wanted_out) {

+    frame_count = oldest->frame_count_out;

+    while (frame_count == oldest->frame_count_out) {

         r = ff_filter_graph_run_once(graph);

         if (r < 0)

             return r;

@@ -1408,41 +1413,17 @@ int avfilter_graph_request_oldest(AVFilterGraph *graph)

     return 0;

 }

-static AVFilterLink *graph_run_once_find_filter(AVFilterGraph *graph)

-{

-    unsigned i, j;

-    AVFilterContext *f;

-

-    /* TODO: replace scanning the graph with a priority list */

-    for (i = 0; i < graph->nb_filters; i++) {

-        f = graph->filters[i];

-        for (j = 0; j < f->nb_outputs; j++)

-            if (f->outputs[j]->frame_wanted_in)

-                return f->outputs[j];

-    }

-    for (i = 0; i < graph->nb_filters; i++) {

-        f = graph->filters[i];

-        for (j = 0; j < f->nb_outputs; j++)

-            if (f->outputs[j]->frame_wanted_out)

-                return f->outputs[j];

-    }

-    return NULL;

-}

-

 int ff_filter_graph_run_once(AVFilterGraph *graph)

 {

-    AVFilterLink *link;

-    int ret;

-

-    link = graph_run_once_find_filter(graph);

-    if (!link) {

-        av_log(NULL, AV_LOG_WARNING, "Useless run of a filter graph\n");

+    AVFilterContext *filter;

+    unsigned i;

+

+    av_assert0(graph->nb_filters);

+    filter = graph->filters[0];

+    for (i = 1; i < graph->nb_filters; i++)

+        if (graph->filters[i]->ready > filter->ready)

+            filter = graph->filters[i];

+    if (!filter->ready)

         return AVERROR(EAGAIN);

-    }

-    ret = ff_request_frame_to_filter(link);

-    if (ret == AVERROR_EOF)

-        /* local EOF will be forwarded through request_frame() /

-           set_status() until it reaches the sink */

-        ret = 0;

-    return ret < 0 ? ret : 1;

+    return ff_filter_activate(filter);

 }

@@ -31,6 +31,9 @@

 #include "libavutil/mathematics.h"

 #include "libavutil/opt.h"

+#define FF_INTERNAL_FIELDS 1

+#include "framequeue.h"

+

 #include "audio.h"

 #include "avfilter.h"

 #include "buffersink.h"

@@ -129,18 +132,26 @@ int attribute_align_arg av_buffersink_get_frame_flags(AVFilterContext *ctx, AVFr

 {

     BufferSinkContext *buf = ctx->priv;

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

-    int ret;

+    int peek_in_framequeue = 0, ret;

+    int64_t frame_count;

     AVFrame *cur_frame;

     /* no picref available, fetch it from the filterchain */

     while (!av_fifo_size(buf->fifo)) {

-        if (inlink->status)

-            return inlink->status;

-        if (flags & AV_BUFFERSINK_FLAG_NO_REQUEST)

+        /* if peek_in_framequeue is true later, then ff_request_frame() and

+           the ff_filter_graph_run_once() loop will take a frame from it and

+           move it to the internal fifo, ending the global loop */

+        av_assert0(!peek_in_framequeue);

+        if (inlink->status_out)

+            return inlink->status_out;

+        peek_in_framequeue = ff_framequeue_queued_frames(&inlink->fifo) &&

+                             ff_framequeue_queued_samples(&inlink->fifo) >= inlink->min_samples;

+        if ((flags & AV_BUFFERSINK_FLAG_NO_REQUEST) && !peek_in_framequeue)

             return AVERROR(EAGAIN);

         if ((ret = ff_request_frame(inlink)) < 0)

             return ret;

-        while (inlink->frame_wanted_out) {

+        frame_count = inlink->frame_count_out;

+        while (frame_count == inlink->frame_count_out) {

             ret = ff_filter_graph_run_once(ctx->graph);

             if (ret < 0)

                 return ret;

@@ -184,6 +184,7 @@ static int av_buffersrc_add_frame_internal(AVFilterContext *ctx,

     if (!frame) {

         s->eof = 1;

+        ff_avfilter_link_set_in_status(ctx->outputs[0], AVERROR_EOF, AV_NOPTS_VALUE);

         return 0;

     } else if (s->eof)

         return AVERROR(EINVAL);

@@ -235,9 +236,8 @@ static int av_buffersrc_add_frame_internal(AVFilterContext *ctx,

         return ret;

     }

-    if ((flags & AV_BUFFERSRC_FLAG_PUSH))

-        if ((ret = ctx->output_pads[0].request_frame(ctx->outputs[0])) < 0)

-            return ret;

+    if ((ret = ctx->output_pads[0].request_frame(ctx->outputs[0])) < 0)

+        return ret;

     return 0;

 }

@@ -26,6 +26,10 @@

 #include "libavutil/avassert.h"

 #include "libavutil/avstring.h"

 #include "libavutil/opt.h"

+

+#define FF_INTERNAL_FIELDS 1

+#include "framequeue.h"

+

 #include "avfilter.h"

 #include "bufferqueue.h"

 #include "formats.h"

@@ -59,7 +63,7 @@ inline static int push_frame(AVFilterContext *ctx)

     for (i = 0; i < ctx->nb_inputs; i++) {

         struct FFBufQueue *q = &s->queues[i];

-        if (!q->available && !ctx->inputs[i]->status)

+        if (!q->available && !ctx->inputs[i]->status_out)

             return 0;

         if (q->available) {

             frame = ff_bufqueue_peek(q, 0);

@@ -190,7 +194,7 @@ static int request_frame(AVFilterLink *outlink)

     int i, ret;

     for (i = 0; i < ctx->nb_inputs; i++) {

-        if (!s->queues[i].available && !ctx->inputs[i]->status) {

+        if (!s->queues[i].available && !ctx->inputs[i]->status_out) {

             ret = ff_request_frame(ctx->inputs[i]);

             if (ret != AVERROR_EOF)

                 return ret;

@@ -29,6 +29,7 @@

 #include "avfiltergraph.h"

 #include "formats.h"

 #include "framepool.h"

+#include "framequeue.h"

 #include "thread.h"

 #include "version.h"

 #include "video.h"

@@ -147,6 +148,7 @@ struct AVFilterPad {

 struct AVFilterGraphInternal {

     void *thread;

     avfilter_execute_func *thread_execute;

+    FFFrameQueueGlobal frame_queues;

 };

 struct AVFilterInternal {

@@ -336,6 +338,8 @@ int ff_request_frame(AVFilterLink *link);

 int ff_request_frame_to_filter(AVFilterLink *link);

+int ff_filter_frame_to_filter(AVFilterLink *link);

+

 #define AVFILTER_DEFINE_CLASS(fname)            \

     static const AVClass fname##_class = {      \

         .class_name = #fname,                   \

@@ -376,6 +380,8 @@ int ff_filter_frame(AVFilterLink *link, AVFrame *frame);

  */

 AVFilterContext *ff_filter_alloc(const AVFilter *filter, const char *inst_name);

+int ff_filter_activate(AVFilterContext *filter);

+

 /**

  * Remove a filter from a graph;

  */

@@ -30,6 +30,9 @@

 #include "libavutil/mem.h"

 #include "libavutil/opt.h"

+#define FF_INTERNAL_FIELDS 1

+#include "framequeue.h"

+

 #include "avfilter.h"

 #include "audio.h"

 #include "formats.h"

@@ -78,7 +81,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)

     for (i = 0; i < ctx->nb_outputs; i++) {

         AVFrame *buf_out;

-        if (ctx->outputs[i]->status)