diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index 828b270..6109e58 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -377,6 +377,7 @@ struct AVFilterContext {
     unsigned ready;
 };
 
+#if FF_API_AVFILTERLINK_PUBLIC
 /**
  * A link between two filters. This contains pointers to the source and
  * destination filters between which this link exists, and the indexes of
@@ -593,6 +594,7 @@ struct AVFilterLink {
 #endif /* FF_INTERNAL_FIELDS */
 
 };
+#endif /* FF_API_AVFILTERLINK_PUBLIC */
 
 /**
  * Link two filters together.
diff --git a/libavfilter/internal.h b/libavfilter/internal.h
index a8b69fd..599be24 100644
--- a/libavfilter/internal.h
+++ b/libavfilter/internal.h
@@ -145,6 +145,205 @@ struct AVFilterPad {
     int needs_writable;
 };
 
+#if !FF_API_AVFILTERLINK_PUBLIC
+/**
+ * A link between two filters. This contains pointers to the source and
+ * destination filters between which this link exists, and the indexes of
+ * the pads involved. In addition, this link also contains the parameters
+ * which have been negotiated and agreed upon between the filter, such as
+ * image dimensions, format, etc.
+ */
+struct AVFilterLink {
+    AVFilterContext *src;       ///< source filter
+    AVFilterPad *srcpad;        ///< output pad on the source filter
+
+    AVFilterContext *dst;       ///< dest filter
+    AVFilterPad *dstpad;        ///< input pad on the dest filter
+
+    enum AVMediaType type;      ///< filter media type
+
+    /* These parameters apply only to video */
+    int w;                      ///< agreed upon image width
+    int h;                      ///< agreed upon image height
+    AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
+    /* These parameters apply only to audio */
+    uint64_t channel_layout;    ///< channel layout of current buffer (see libavutil/channel_layout.h)
+    int sample_rate;            ///< samples per second
+
+    int format;                 ///< agreed upon media format
+
+    /**
+     * Define the time base used by the PTS of the frames/samples
+     * which will pass through this link.
+     * During the configuration stage, each filter is supposed to
+     * change only the output timebase, while the timebase of the
+     * input link is assumed to be an unchangeable property.
+     */
+    AVRational time_base;
+
+    /**
+     * Lists of formats and channel layouts supported by the input and output
+     * filters respectively. These lists are used for negotiating the format
+     * to actually be used, which will be loaded into the format and
+     * channel_layout members, above, when chosen.
+     *
+     */
+    AVFilterFormats *in_formats;
+    AVFilterFormats *out_formats;
+
+    /**
+     * Lists of channel layouts and sample rates used for automatic
+     * negotiation.
+     */
+    AVFilterFormats  *in_samplerates;
+    AVFilterFormats *out_samplerates;
+    struct AVFilterChannelLayouts  *in_channel_layouts;
+    struct AVFilterChannelLayouts *out_channel_layouts;
+
+    /**
+     * Audio only, the destination filter sets this to a non-zero value to
+     * request that buffers with the given number of samples should be sent to
+     * it. AVFilterPad.needs_fifo must also be set on the corresponding input
+     * pad.
+     * Last buffer before EOF will be padded with silence.
+     */
+    int request_samples;
+
+    /** stage of the initialization of the link properties (dimensions, etc) */
+    enum {
+        AVLINK_UNINIT = 0,      ///< not started
+        AVLINK_STARTINIT,       ///< started, but incomplete
+        AVLINK_INIT             ///< complete
+    } init_state;
+
+    /**
+     * Graph the filter belongs to.
+     */
+    struct AVFilterGraph *graph;
+
+    /**
+     * Current timestamp of the link, as defined by the most recent
+     * frame(s), in link time_base units.
+     */
+    int64_t current_pts;
+
+    /**
+     * Current timestamp of the link, as defined by the most recent
+     * frame(s), in AV_TIME_BASE units.
+     */
+    int64_t current_pts_us;
+
+    /**
+     * Index in the age array.
+     */
+    int age_index;
+
+    /**
+     * Frame rate of the stream on the link, or 1/0 if unknown or variable;
+     * if left to 0/0, will be automatically copied from the first input
+     * of the source filter if it exists.
+     *
+     * Sources should set it to the best estimation of the real frame rate.
+     * If the source frame rate is unknown or variable, set this to 1/0.
+     * Filters should update it if necessary depending on their function.
+     * Sinks can use it to set a default output frame rate.
+     * It is similar to the r_frame_rate field in AVStream.
+     */
+    AVRational frame_rate;
+
+    /**
+     * Buffer partially filled with samples to achieve a fixed/minimum size.
+     */
+    AVFrame *partial_buf;
+
+    /**
+     * Size of the partial buffer to allocate.
+     * Must be between min_samples and max_samples.
+     */
+    int partial_buf_size;
+
+    /**
+     * Minimum number of samples to filter at once. If filter_frame() is
+     * called with fewer samples, it will accumulate them in partial_buf.
+     * This field and the related ones must not be changed after filtering
+     * has started.
+     * If 0, all related fields are ignored.
+     */
+    int min_samples;
+
+    /**
+     * Maximum number of samples to filter at once. If filter_frame() is
+     * called with more samples, it will split them.
+     */
+    int max_samples;
+
+    /**
+     * Number of channels.
+     */
+    int channels;
+
+    /**
+     * Link processing flags.
+     */
+    unsigned flags;
+
+    /**
+     * Number of past frames sent through the link.
+     */
+    int64_t frame_count_in, frame_count_out;
+
+    /**
+     * A pointer to a FFVideoFramePool struct.
+     */
+    void *video_frame_pool;
+
+    /**
+     * 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.
+     */
+    int frame_wanted_out;
+
+    /**
+     * For hwaccel pixel formats, this should be a reference to the
+     * AVHWFramesContext describing the frames.
+     */
+    AVBufferRef *hw_frames_ctx;
+
+    /**
+     * 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_API_AVFILTERLINK_PUBLIC */
+
 struct AVFilterGraphInternal {
     void *thread;
     avfilter_execute_func *thread_execute;
diff --git a/libavfilter/version.h b/libavfilter/version.h
index e3bd8d0..8256781 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -67,5 +67,8 @@
 #ifndef FF_API_NOCONST_GET_NAME
 #define FF_API_NOCONST_GET_NAME             (LIBAVFILTER_VERSION_MAJOR < 7)
 #endif
+#ifndef FF_API_AVFILTERLINK_PUBLIC
+#define FF_API_AVFILTERLINK_PUBLIC          (LIBAVFILTER_VERSION_MAJOR < 8)
+#endif
 
 #endif /* AVFILTER_VERSION_H */
