lavfi: generic hardware surface upload and download filters

Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 212 insertions, 0 deletions

diff --git a/libavfilter/vf_hwdownload.c b/libavfilter/vf_hwdownload.c
new file mode 100644
index 0000000000..0ba1d98aa6
--- /dev/null
+++ b/libavfilter/vf_hwdownload.c
@@ -0,0 +1,212 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/buffer.h"
+#include "libavutil/hwcontext.h"
+#include "libavutil/log.h"
+#include "libavutil/mem.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct HWDownloadContext {
+    const AVClass *class;
+
+    AVBufferRef       *hwframes_ref;
+    AVHWFramesContext *hwframes;
+} HWDownloadContext;
+
+static int hwdownload_query_formats(AVFilterContext *avctx)
+{
+    AVFilterFormats  *infmts = NULL;
+    AVFilterFormats *outfmts = NULL;
+    const AVPixFmtDescriptor *desc;
+    int err;
+
+    for (desc = av_pix_fmt_desc_next(NULL); desc;
+         desc = av_pix_fmt_desc_next(desc)) {
+        if (desc->flags & AV_PIX_FMT_FLAG_HWACCEL)
+            err = ff_add_format(&infmts,  av_pix_fmt_desc_get_id(desc));
+        else
+            err = ff_add_format(&outfmts, av_pix_fmt_desc_get_id(desc));
+        if (err) {
+            ff_formats_unref(&infmts);
+            ff_formats_unref(&outfmts);
+            return err;
+        }
+    }
+
+    ff_formats_ref(infmts,  &avctx->inputs[0]->out_formats);
+    ff_formats_ref(outfmts, &avctx->outputs[0]->in_formats);
+    return 0;
+}
+
+static int hwdownload_config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *avctx = inlink->dst;
+    HWDownloadContext *ctx = avctx->priv;
+
+    av_buffer_unref(&ctx->hwframes_ref);
+
+    if (!inlink->hw_frames_ctx) {
+        av_log(ctx, AV_LOG_ERROR, "The input must have a hardware frame "
+               "reference.\n");
+        return AVERROR(EINVAL);
+    }
+
+    ctx->hwframes_ref = av_buffer_ref(inlink->hw_frames_ctx);
+    if (!ctx->hwframes_ref)
+        return AVERROR(ENOMEM);
+
+    ctx->hwframes = (AVHWFramesContext*)ctx->hwframes_ref->data;
+
+    return 0;
+}
+
+static int hwdownload_config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *avctx = outlink->src;
+    AVFilterLink *inlink   = avctx->inputs[0];
+    HWDownloadContext *ctx = avctx->priv;
+    enum AVPixelFormat *formats;
+    int err, i, found;
+
+    if (!ctx->hwframes_ref)
+        return AVERROR(EINVAL);
+
+    err = av_hwframe_transfer_get_formats(ctx->hwframes_ref,
+                                          AV_HWFRAME_TRANSFER_DIRECTION_FROM,
+                                          &formats, 0);
+    if (err < 0)
+        return err;
+
+    found = 0;
+    for (i = 0; formats[i] != AV_PIX_FMT_NONE; i++) {
+        if (formats[i] == outlink->format) {
+            found = 1;
+            break;
+        }
+    }
+    av_freep(&formats);
+
+    if (!found) {
+        av_log(ctx, AV_LOG_ERROR, "Invalid output format %s for hwframe "
+               "download.\n", av_get_pix_fmt_name(outlink->format));
+        return AVERROR(EINVAL);
+    }
+
+    outlink->w = inlink->w;
+    outlink->h = inlink->h;
+
+    return 0;
+}
+
+static int hwdownload_filter_frame(AVFilterLink *link, AVFrame *input)
+{
+    AVFilterContext *avctx = link->dst;
+    AVFilterLink  *outlink = avctx->outputs[0];
+    HWDownloadContext *ctx = avctx->priv;
+    AVFrame *output = NULL;
+    int err;
+
+    if (!ctx->hwframes_ref || !input->hw_frames_ctx) {
+        av_log(ctx, AV_LOG_ERROR, "Input frames must have hardware context.\n");
+        err = AVERROR(EINVAL);
+        goto fail;
+    }
+    if ((void*)ctx->hwframes != input->hw_frames_ctx->data) {
+        av_log(ctx, AV_LOG_ERROR, "Input frame is not the in the configured "
+               "hwframe context.\n");
+        err = AVERROR(EINVAL);
+        goto fail;
+    }
+
+    output = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!output) {
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    err = av_hwframe_transfer_data(output, input, 0);
+    if (err < 0) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to download frame: %d.\n", err);
+        goto fail;
+    }
+
+    err = av_frame_copy_props(output, input);
+    if (err < 0)
+        goto fail;
+
+    av_frame_free(&input);
+
+    return ff_filter_frame(avctx->outputs[0], output);
+
+fail:
+    av_frame_free(&input);
+    av_frame_free(&output);
+    return err;
+}
+
+static av_cold void hwdownload_uninit(AVFilterContext *avctx)
+{
+    HWDownloadContext *ctx = avctx->priv;
+
+    av_buffer_unref(&ctx->hwframes_ref);
+}
+
+static const AVClass hwdownload_class = {
+    .class_name = "hwdownload",
+    .item_name  = av_default_item_name,
+    .option     = NULL,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+static const AVFilterPad hwdownload_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = hwdownload_config_input,
+        .filter_frame = hwdownload_filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad hwdownload_outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = hwdownload_config_output,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_hwdownload = {
+    .name          = "hwdownload",
+    .description   = NULL_IF_CONFIG_SMALL("Download a hardware frame to a normal frame"),
+    .uninit        = hwdownload_uninit,
+    .query_formats = hwdownload_query_formats,
+    .priv_size     = sizeof(HWDownloadContext),
+    .priv_class    = &hwdownload_class,
+    .inputs        = hwdownload_inputs,
+    .outputs       = hwdownload_outputs,
+};