1. ffmpeg
  2. Commit 62b11db0a08cbb8c338e413a0d1707a8c81ae24e
Browse code

lavfi: add FFFrameQueue API.

Nicolas George authored on 2015/12/04 04:05:14
Showing 3 changed files
libavfilter/Makefile
History View file @ 62b11db
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@@ -18,6 +18,7 @@ OBJS = allfilters.o                                                     \
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        fifo.o                                                           \
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        formats.o                                                        \
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        framepool.o                                                      \
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+       framequeue.o                                                     \
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        graphdump.o                                                      \
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        graphparser.o                                                    \
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        opencl_allkernels.o                                              \
libavfilter/framequeue.c
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new file mode 100644
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@@ -0,0 +1,123 @@
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+/*
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+ * Generic frame queue
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+ * Copyright (c) 2016 Nicolas George
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+ *
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+ * This file is part of FFmpeg.
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+ *
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+ * FFmpeg is free software; you can redistribute it and/or
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+ * modify it under the terms of the GNU Lesser General Public License
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+ * as published by the Free Software Foundation; either
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+ * version 2.1 of the License, or (at your option) any later version.
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+ *
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+ * FFmpeg is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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+ * GNU Lesser General Public License for more details.
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+ *
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+ * You should have received a copy of the GNU Lesser General Public License
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+ * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
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+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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+ */
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+
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+#include "libavutil/avassert.h"
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+#include "framequeue.h"
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+
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+static inline FFFrameBucket *bucket(FFFrameQueue *fq, size_t idx)
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+{
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+    return &fq->queue[(fq->tail + idx) & (fq->allocated - 1)];
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+}
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+
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+void ff_framequeue_global_init(FFFrameQueueGlobal *fqg)
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+{
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+}
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+
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+static void check_consistency(FFFrameQueue *fq)
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+{
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+#if ASSERT_LEVEL >= 2
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+    uint64_t nb_samples = 0;
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+    size_t i;
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+
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+    av_assert0(fq->queued == fq->total_frames_head - fq->total_frames_tail);
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+    for (i = 0; i < fq->queued; i++)
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+        nb_samples += bucket(fq, i)->frame->nb_samples;
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+    av_assert0(nb_samples == fq->total_samples_head - fq->total_samples_tail);
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+#endif
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+}
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+
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+void ff_framequeue_init(FFFrameQueue *fq, FFFrameQueueGlobal *fqg)
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+{
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+    fq->queue = &fq->first_bucket;
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+    fq->allocated = 1;
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+}
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+
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+void ff_framequeue_free(FFFrameQueue *fq)
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+{
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+    while (fq->queued) {
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+        AVFrame *frame = ff_framequeue_take(fq);
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+        av_frame_free(&frame);
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+    }
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+    if (fq->queue != &fq->first_bucket)
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+        av_freep(&fq->queue);
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+}
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+
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+int ff_framequeue_add(FFFrameQueue *fq, AVFrame *frame)
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+{
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+    FFFrameBucket *b;
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+
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+    check_consistency(fq);
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+    if (fq->queued == fq->allocated) {
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+        if (fq->allocated == 1) {
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+            size_t na = 8;
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+            FFFrameBucket *nq = av_realloc_array(NULL, na, sizeof(*nq));
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+            if (!nq)
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+                return AVERROR(ENOMEM);
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+            nq[0] = fq->queue[0];
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+            fq->queue = nq;
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+            fq->allocated = na;
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+        } else {
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+            size_t na = fq->allocated << 1;
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+            FFFrameBucket *nq = av_realloc_array(fq->queue, na, sizeof(*nq));
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+            if (!nq)
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+                return AVERROR(ENOMEM);
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+            if (fq->tail + fq->queued > fq->allocated)
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+                memmove(nq + fq->allocated, nq,
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+                        (fq->tail + fq->queued - fq->allocated) * sizeof(*nq));
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+            fq->queue = nq;
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+            fq->allocated = na;
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+        }
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+    }
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+    b = bucket(fq, fq->queued);
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+    b->frame = frame;
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+    fq->queued++;
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+    fq->total_frames_head++;
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+    fq->total_samples_head += frame->nb_samples;
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+    check_consistency(fq);
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+    return 0;
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+}
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+
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+AVFrame *ff_framequeue_take(FFFrameQueue *fq)
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+{
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+    FFFrameBucket *b;
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+
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+    check_consistency(fq);
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+    av_assert1(fq->queued);
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+    b = bucket(fq, 0);
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+    fq->queued--;
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+    fq->tail++;
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+    fq->tail &= fq->allocated - 1;
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+    fq->total_frames_tail++;
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+    fq->total_samples_tail += b->frame->nb_samples;
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+    check_consistency(fq);
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+    return b->frame;
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+}
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+
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+AVFrame *ff_framequeue_peek(FFFrameQueue *fq, size_t idx)
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+{
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+    FFFrameBucket *b;
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+
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+    check_consistency(fq);
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+    av_assert1(idx < fq->queued);
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+    b = bucket(fq, idx);
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+    check_consistency(fq);
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+    return b->frame;
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+}
libavfilter/framequeue.h
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new file mode 100644
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@@ -0,0 +1,173 @@
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+/*
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+ * Generic frame queue
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+ * Copyright (c) 2016 Nicolas George
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+ *
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+ * This file is part of FFmpeg.
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+ *
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+ * FFmpeg is free software; you can redistribute it and/or
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+ * modify it under the terms of the GNU Lesser General Public License
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+ * as published by the Free Software Foundation; either
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+ * version 2.1 of the License, or (at your option) any later version.
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+ *
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+ * FFmpeg is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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+ * GNU Lesser General Public License for more details.
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+ *
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+ * You should have received a copy of the GNU Lesser General Public License
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+ * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
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+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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+ */
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+
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+#ifndef AVFILTER_FRAMEQUEUE_H
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+#define AVFILTER_FRAMEQUEUE_H
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+
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+/**
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+ * FFFrameQueue: simple AVFrame queue API
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+ *
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+ * Note: this API is not thread-safe. Concurrent access to the same queue
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+ * must be protected by a mutex or any synchronization mechanism.
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+ */
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+
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+#include "libavutil/frame.h"
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+
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+typedef struct FFFrameBucket {
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+    AVFrame *frame;
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+} FFFrameBucket;
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+
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+/**
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+ * Structure to hold global options and statistics for frame queues.
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+ *
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+ * This structure is intended to allow implementing global control of the
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+ * frame queues, including memory consumption caps.
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+ *
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+ * It is currently empty.
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+ */
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+typedef struct FFFrameQueueGlobal {
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+} FFFrameQueueGlobal;
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+
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+/**
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+ * Queue of AVFrame pointers.
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+ */
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+typedef struct FFFrameQueue {
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+
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+    /**
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+     * Array of allocated buckets, used as a circular buffer.
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+     */
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+    FFFrameBucket *queue;
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+
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+    /**
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+     * Size of the array of buckets.
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+     */
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+    size_t allocated;
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+
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+    /**
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+     * Tail of the queue.
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+     * It is the index in the array of the next frame to take.
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+     */
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+    size_t tail;
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+
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+    /**
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+     * Number of currently queued frames.
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+     */
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+    size_t queued;
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+
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+    /**
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+     * Pre-allocated bucket for queues of size 1.
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+     */
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+    FFFrameBucket first_bucket;
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+
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+    /**
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+     * Total number of frames entered in the queue.
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+     */
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+    uint64_t total_frames_head;
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+
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+    /**
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+     * Total number of frames dequeued from the queue.
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+     * queued = total_frames_head - total_frames_tail
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+     */
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+    uint64_t total_frames_tail;
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+
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+    /**
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+     * Total number of samples entered in the queue.
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+     */
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+    uint64_t total_samples_head;
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+
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+    /**
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+     * Total number of samples dequeued from the queue.
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+     * queued_samples = total_samples_head - total_samples_tail
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+     */
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+    uint64_t total_samples_tail;
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+
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+} FFFrameQueue;
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+
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+/**
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+ * Init a global structure.
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+ */
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+void ff_framequeue_global_init(FFFrameQueueGlobal *fqg);
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+
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+/**
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+ * Init a frame queue and attach it to a global structure.
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+ */
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+void ff_framequeue_init(FFFrameQueue *fq, FFFrameQueueGlobal *fqg);
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+
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+/**
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+ * Free the queue and all queued frames.
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+ */
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+void ff_framequeue_free(FFFrameQueue *fq);
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+
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+/**
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+ * Add a frame.
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+ * @return  >=0 or an AVERROR code.
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+ */
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+int ff_framequeue_add(FFFrameQueue *fq, AVFrame *frame);
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+
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+/**
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+ * Take the first frame in the queue.
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+ * Must not be used with empty queues.
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+ */
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+AVFrame *ff_framequeue_take(FFFrameQueue *fq);
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+
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+/**
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+ * Access a frame in the queue, without removing it.
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+ * The first frame is numbered 0; the designated frame must exist.
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+ */
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+AVFrame *ff_framequeue_peek(FFFrameQueue *fq, size_t idx);
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+
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+/**
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+ * Get the number of queued frames.
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+ */
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+static inline size_t ff_framequeue_queued_frames(const FFFrameQueue *fq)
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+{
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+    return fq->queued;
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+}
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+
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+/**
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+ * Get the number of queued samples.
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+ */
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+static inline uint64_t ff_framequeue_queued_samples(const FFFrameQueue *fq)
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+{
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+    return fq->total_samples_head - fq->total_samples_tail;
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+}
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+
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+/**
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+ * Update the statistics after a frame accessed using ff_framequeue_peek()
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+ * was modified.
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+ * Currently used only as a marker.
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+ */
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+static inline void ff_framequeue_update_peeked(FFFrameQueue *fq, size_t idx)
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+{
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+}
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+
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+/**
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+ * Update the sample count in the queue.
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+ *
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+ * This function must be used when the first frame was accessed using
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+ * ff_framequeue_peek() and samples were removed from it.
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+ */
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+static inline void ff_framequeue_skip_samples(FFFrameQueue *fq, size_t n)
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+{
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+    fq->total_samples_tail += n;
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+}
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+
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+#endif /* AVFILTER_FRAMEQUEUE_H */