@@ -26,28 +26,27 @@

 #include "libswresample/swresample.h" // only for SWR_CH_MAX

 #include "avfilter.h"

 #include "audio.h"

+#include "bufferqueue.h"

 #include "internal.h"

-#define QUEUE_SIZE 16

-

 typedef struct {

     int nb_in_ch[2];       /**< number of channels for each input */

     int route[SWR_CH_MAX]; /**< channels routing, see copy_samples */

     int bps;

-    struct amerge_queue {

-        AVFilterBufferRef *buf[QUEUE_SIZE];

-        int nb_buf, nb_samples, pos;

-    } queue[2];

+    struct amerge_input {

+        struct FFBufQueue queue;

+        int nb_samples;

+        int pos;

+    } in[2];

 } AMergeContext;

 static av_cold void uninit(AVFilterContext *ctx)

 {

     AMergeContext *am = ctx->priv;

-    int i, j;

+    int i;

     for (i = 0; i < 2; i++)

-        for (j = 0; j < am->queue[i].nb_buf; j++)

-            avfilter_unref_buffer(am->queue[i].buf[j]);

+        ff_bufqueue_discard_all(&am->in[i].queue);

 }

 static int query_formats(AVFilterContext *ctx)

@@ -144,7 +143,7 @@ static int request_frame(AVFilterLink *outlink)

     int i, ret;

     for (i = 0; i < 2; i++)

-        if (!am->queue[i].nb_samples)

+        if (!am->in[i].nb_samples)

             if ((ret = avfilter_request_frame(ctx->inputs[i])) < 0)

                 return ret;

     return 0;

@@ -189,47 +188,38 @@ static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)

     AMergeContext *am = ctx->priv;

     AVFilterLink *const outlink = ctx->outputs[0];

     int input_number = inlink == ctx->inputs[1];

-    struct amerge_queue *inq = &am->queue[input_number];

     int nb_samples, ns, i;

-    AVFilterBufferRef *outbuf, **inbuf[2];

+    AVFilterBufferRef *outbuf, *inbuf[2];

     uint8_t *ins[2], *outs;

-    if (inq->nb_buf == QUEUE_SIZE) {

-        av_log(ctx, AV_LOG_ERROR, "Packet queue overflow; dropped\n");

-        avfilter_unref_buffer(insamples);

-        return;

-    }

-    inq->buf[inq->nb_buf++] = avfilter_ref_buffer(insamples, AV_PERM_READ |

-                                                             AV_PERM_PRESERVE);

-    inq->nb_samples += insamples->audio->nb_samples;

-    avfilter_unref_buffer(insamples);

-    if (!am->queue[!input_number].nb_samples)

+    ff_bufqueue_add(ctx, &am->in[input_number].queue, insamples);

+    am->in[input_number].nb_samples += insamples->audio->nb_samples;

+    if (!am->in[!input_number].nb_samples)

         return;

-    nb_samples = FFMIN(am->queue[0].nb_samples,

-                       am->queue[1].nb_samples);

-    outbuf = ff_get_audio_buffer(ctx->outputs[0], AV_PERM_WRITE,

-                                       nb_samples);

+    nb_samples = FFMIN(am->in[0].nb_samples,

+                       am->in[1].nb_samples);

+    outbuf = ff_get_audio_buffer(ctx->outputs[0], AV_PERM_WRITE, nb_samples);

     outs = outbuf->data[0];

     for (i = 0; i < 2; i++) {

-        inbuf[i] = am->queue[i].buf;

-        ins[i] = (*inbuf[i])->data[0] +

-                 am->queue[i].pos * am->nb_in_ch[i] * am->bps;

+        inbuf[i] = ff_bufqueue_peek(&am->in[i].queue, 0);

+        ins[i] = inbuf[i]->data[0] +

+                 am->in[i].pos * am->nb_in_ch[i] * am->bps;

     }

-    outbuf->pts = (*inbuf[0])->pts == AV_NOPTS_VALUE ? AV_NOPTS_VALUE :

-                  (*inbuf[0])->pts +

-                  av_rescale_q(am->queue[0].pos,

+    outbuf->pts = inbuf[0]->pts == AV_NOPTS_VALUE ? AV_NOPTS_VALUE :

+                  inbuf[0]->pts +

+                  av_rescale_q(am->in[0].pos,

                                (AVRational){ 1, ctx->inputs[0]->sample_rate },

                                ctx->outputs[0]->time_base);

-    avfilter_copy_buffer_ref_props(outbuf, *inbuf[0]);

+    avfilter_copy_buffer_ref_props(outbuf, inbuf[0]);

     outbuf->audio->nb_samples     = nb_samples;

     outbuf->audio->channel_layout = outlink->channel_layout;

     while (nb_samples) {

         ns = nb_samples;

         for (i = 0; i < 2; i++)

-            ns = FFMIN(ns, (*inbuf[i])->audio->nb_samples - am->queue[i].pos);

+            ns = FFMIN(ns, inbuf[i]->audio->nb_samples - am->in[i].pos);

         /* Unroll the most common sample formats: speed +~350% for the loop,

            +~13% overall (including two common decoders) */

         switch (am->bps) {

@@ -249,25 +239,17 @@ static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)

         nb_samples -= ns;

         for (i = 0; i < 2; i++) {

-            am->queue[i].nb_samples -= ns;

-            am->queue[i].pos += ns;

-            if (am->queue[i].pos == (*inbuf[i])->audio->nb_samples) {

-                am->queue[i].pos = 0;

-                avfilter_unref_buffer(*inbuf[i]);

-                *inbuf[i] = NULL;

-                inbuf[i]++;

-                ins[i] = *inbuf[i] ? (*inbuf[i])->data[0] : NULL;

+            am->in[i].nb_samples -= ns;

+            am->in[i].pos += ns;

+            if (am->in[i].pos == inbuf[i]->audio->nb_samples) {

+                am->in[i].pos = 0;

+                avfilter_unref_buffer(inbuf[i]);

+                ff_bufqueue_get(&am->in[i].queue);

+                inbuf[i] = ff_bufqueue_peek(&am->in[i].queue, 0);

+                ins[i] = inbuf[i] ? inbuf[i]->data[0] : NULL;

             }

         }

     }

-    for (i = 0; i < 2; i++) {

-        int nbufused = inbuf[i] - am->queue[i].buf;

-        if (nbufused) {

-            am->queue[i].nb_buf -= nbufused;

-            memmove(am->queue[i].buf, inbuf[i],

-                    am->queue[i].nb_buf * sizeof(**inbuf));

-        }

-    }

     ff_filter_samples(ctx->outputs[0], outbuf);

 }

@@ -283,11 +265,11 @@ AVFilter avfilter_af_amerge = {

         { .name             = "in1",

           .type             = AVMEDIA_TYPE_AUDIO,

           .filter_samples   = filter_samples,

-          .min_perms        = AV_PERM_READ, },

+          .min_perms        = AV_PERM_READ | AV_PERM_PRESERVE, },

         { .name             = "in2",

           .type             = AVMEDIA_TYPE_AUDIO,

           .filter_samples   = filter_samples,

-          .min_perms        = AV_PERM_READ, },

+          .min_perms        = AV_PERM_READ | AV_PERM_PRESERVE, },

         { .name = NULL }

     },

     .outputs   = (const AVFilterPad[]) {