lavfi: add vsink_buffer, and use it in ff* tools

Also add the public interface libavfilter/vsink_buffer.h.

1 files changed, 111 insertions, 0 deletions

diff --git a/libavfilter/vsink_buffer.c b/libavfilter/vsink_buffer.c
new file mode 100644
index 0000000000..c0824606a9
--- /dev/null
+++ b/libavfilter/vsink_buffer.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2011 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
+ * buffer video sink
+ */
+
+#include "avfilter.h"
+#include "vsink_buffer.h"
+
+typedef struct {
+    AVFilterBufferRef *picref;   ///< cached picref
+    enum PixelFormat *pix_fmts;  ///< accepted pixel formats, must be terminated with -1
+} BufferSinkContext;
+
+static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+    BufferSinkContext *buf = ctx->priv;
+
+    if (!opaque) {
+        av_log(ctx, AV_LOG_ERROR, "No opaque field provided, which is required.\n");
+        return AVERROR(EINVAL);
+    }
+
+    buf->pix_fmts = opaque;
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    BufferSinkContext *buf = ctx->priv;
+
+    if (buf->picref)
+        avfilter_unref_buffer(buf->picref);
+    buf->picref = NULL;
+}
+
+static void end_frame(AVFilterLink *inlink)
+{
+    BufferSinkContext *buf = inlink->dst->priv;
+
+    if (buf->picref)            /* drop the last cached frame */
+        avfilter_unref_buffer(buf->picref);
+    buf->picref = inlink->cur_buf;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    BufferSinkContext *buf = ctx->priv;
+
+    avfilter_set_common_formats(ctx, avfilter_make_format_list(buf->pix_fmts));
+    return 0;
+}
+
+int av_vsink_buffer_get_video_buffer_ref(AVFilterContext *ctx,
+                                         AVFilterBufferRef **picref, int flags)
+{
+    BufferSinkContext *buf = ctx->priv;
+    AVFilterLink *inlink = ctx->inputs[0];
+    int ret;
+    *picref = NULL;
+
+    /* no picref available, fetch it from the filterchain */
+    if (!buf->picref) {
+        if ((ret = avfilter_request_frame(inlink)) < 0)
+            return ret;
+    }
+
+    if (!buf->picref)
+        return AVERROR(EINVAL);
+
+    *picref = buf->picref;
+    if (!(flags & AV_VSINK_BUF_FLAG_PEEK))
+        buf->picref = NULL;
+
+    return 0;
+}
+
+AVFilter avfilter_vsink_buffersink = {
+    .name      = "buffersink",
+    .priv_size = sizeof(BufferSinkContext),
+    .init      = init,
+    .uninit    = uninit,
+
+    .query_formats = query_formats,
+
+    .inputs    = (AVFilterPad[]) {{ .name          = "default",
+                                    .type          = AVMEDIA_TYPE_VIDEO,
+                                    .end_frame     = end_frame,
+                                    .min_perms     = AV_PERM_READ, },
+                                  { .name = NULL }},
+    .outputs   = (AVFilterPad[]) {{ .name = NULL }},
+};