videotoolbox: add hwcontext support

This adds tons of code for no other benefit than making VideoToolbox
support conform with the new hwaccel API (using hw_device_ctx and
hw_frames_ctx).

Since VideoToolbox decoding does not actually require the user to
allocate frames, the new code does mostly nothing.

One benefit is that ffmpeg_videotoolbox.c can be dropped once generic
hwaccel support for ffmpeg.c is merged from Libav.

Does not consider VDA or VideoToolbox encoding.

Fun fact: the frame transfer functions are copied from vaapi, as the
mapping makes copying generic boilerplate. Mapping itself is not
exported by the VT code, because I don't know how to test.

1 files changed, 243 insertions, 0 deletions

diff --git a/libavutil/hwcontext_videotoolbox.c b/libavutil/hwcontext_videotoolbox.c
new file mode 100644
index 0000000000..cc00f1f2f2
--- /dev/null
+++ b/libavutil/hwcontext_videotoolbox.c
@@ -0,0 +1,243 @@
+/*
+ * 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
+ */
+
+#include "config.h"
+
+#include <stdint.h>
+#include <string.h>
+
+#include <VideoToolbox/VideoToolbox.h>
+
+#include "buffer.h"
+#include "common.h"
+#include "hwcontext.h"
+#include "hwcontext_internal.h"
+#include "hwcontext_videotoolbox.h"
+#include "mem.h"
+#include "pixfmt.h"
+#include "pixdesc.h"
+
+static const struct {
+    uint32_t cv_fmt;
+    enum AVPixelFormat pix_fmt;
+} cv_pix_fmts[] = {
+    { kCVPixelFormatType_420YpCbCr8Planar,              AV_PIX_FMT_YUV420P },
+    { kCVPixelFormatType_422YpCbCr8,                    AV_PIX_FMT_UYVY422 },
+    { kCVPixelFormatType_32BGRA,                        AV_PIX_FMT_BGRA },
+#ifdef kCFCoreFoundationVersionNumber10_7
+    { kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange,  AV_PIX_FMT_NV12 },
+#endif
+};
+
+enum AVPixelFormat av_map_videotoolbox_format_to_pixfmt(uint32_t cv_fmt)
+{
+    int i;
+    for (i = 0; i < FF_ARRAY_ELEMS(cv_pix_fmts); i++) {
+        if (cv_pix_fmts[i].cv_fmt == cv_fmt)
+            return cv_pix_fmts[i].pix_fmt;
+    }
+    return AV_PIX_FMT_NONE;
+}
+
+uint32_t av_map_videotoolbox_format_from_pixfmt(enum AVPixelFormat pix_fmt)
+{
+    int i;
+    for (i = 0; i < FF_ARRAY_ELEMS(cv_pix_fmts); i++) {
+        if (cv_pix_fmts[i].pix_fmt == pix_fmt)
+            return cv_pix_fmts[i].cv_fmt;
+    }
+    return 0;
+}
+
+static int vt_get_buffer(AVHWFramesContext *ctx, AVFrame *frame)
+{
+    frame->buf[0] = av_buffer_pool_get(ctx->pool);
+    if (!frame->buf[0])
+        return AVERROR(ENOMEM);
+
+    frame->data[3] = frame->buf[0]->data;
+    frame->format  = AV_PIX_FMT_VIDEOTOOLBOX;
+    frame->width   = ctx->width;
+    frame->height  = ctx->height;
+
+    return 0;
+}
+
+static int vt_transfer_get_formats(AVHWFramesContext *ctx,
+                                   enum AVHWFrameTransferDirection dir,
+                                   enum AVPixelFormat **formats)
+{
+    enum AVPixelFormat *fmts = av_malloc_array(2, sizeof(*fmts));
+    if (!fmts)
+        return AVERROR(ENOMEM);
+
+    fmts[0] = ctx->sw_format;
+    fmts[1] = AV_PIX_FMT_NONE;
+
+    *formats = fmts;
+    return 0;
+}
+
+static void vt_unmap(AVHWFramesContext *ctx, HWMapDescriptor *hwmap)
+{
+    CVPixelBufferRef pixbuf = (CVPixelBufferRef)hwmap->source->data[3];
+
+    CVPixelBufferUnlockBaseAddress(pixbuf, (uintptr_t)hwmap->priv);
+}
+
+static int vt_map_frame(AVHWFramesContext *ctx, AVFrame *dst, const AVFrame *src,
+                        int flags)
+{
+    CVPixelBufferRef pixbuf = (CVPixelBufferRef)src->data[3];
+    OSType pixel_format = CVPixelBufferGetPixelFormatType(pixbuf);
+    CVReturn err;
+    uint32_t map_flags = 0;
+    int ret;
+    int i;
+    enum AVPixelFormat format;
+
+    format = av_map_videotoolbox_format_to_pixfmt(pixel_format);
+    if (dst->format != format) {
+        av_log(ctx, AV_LOG_ERROR, "Unsupported or mismatching pixel format: %s\n",
+               av_fourcc2str(pixel_format));
+        return AVERROR_UNKNOWN;
+    }
+
+    if (CVPixelBufferGetWidth(pixbuf) != ctx->width ||
+        CVPixelBufferGetHeight(pixbuf) != ctx->height) {
+        av_log(ctx, AV_LOG_ERROR, "Inconsistent frame dimensions.\n");
+        return AVERROR_UNKNOWN;
+    }
+
+    if (flags == AV_HWFRAME_MAP_READ)
+        map_flags = kCVPixelBufferLock_ReadOnly;
+
+    err = CVPixelBufferLockBaseAddress(pixbuf, map_flags);
+    if (err != kCVReturnSuccess) {
+        av_log(ctx, AV_LOG_ERROR, "Error locking the pixel buffer.\n");
+        return AVERROR_UNKNOWN;
+    }
+
+    if (CVPixelBufferIsPlanar(pixbuf)) {
+        int planes = CVPixelBufferGetPlaneCount(pixbuf);
+        for (i = 0; i < planes; i++) {
+            dst->data[i]     = CVPixelBufferGetBaseAddressOfPlane(pixbuf, i);
+            dst->linesize[i] = CVPixelBufferGetBytesPerRowOfPlane(pixbuf, i);
+        }
+    } else {
+        dst->data[0]     = CVPixelBufferGetBaseAddress(pixbuf);
+        dst->linesize[0] = CVPixelBufferGetBytesPerRow(pixbuf);
+    }
+
+    ret = ff_hwframe_map_create(src->hw_frames_ctx, dst, src, vt_unmap,
+                                (void *)(uintptr_t)map_flags);
+    if (ret < 0)
+        goto unlock;
+
+    return 0;
+
+unlock:
+    CVPixelBufferUnlockBaseAddress(pixbuf, map_flags);
+    return ret;
+}
+
+static int vt_transfer_data_from(AVHWFramesContext *hwfc,
+                                 AVFrame *dst, const AVFrame *src)
+{
+    AVFrame *map;
+    int err;
+
+    if (dst->width > hwfc->width || dst->height > hwfc->height)
+        return AVERROR(EINVAL);
+
+    map = av_frame_alloc();
+    if (!map)
+        return AVERROR(ENOMEM);
+    map->format = dst->format;
+
+    err = vt_map_frame(hwfc, map, src, AV_HWFRAME_MAP_READ);
+    if (err)
+        goto fail;
+
+    map->width  = dst->width;
+    map->height = dst->height;
+
+    err = av_frame_copy(dst, map);
+    if (err)
+        goto fail;
+
+    err = 0;
+fail:
+    av_frame_free(&map);
+    return err;
+}
+
+static int vt_transfer_data_to(AVHWFramesContext *hwfc,
+                               AVFrame *dst, const AVFrame *src)
+{
+    AVFrame *map;
+    int err;
+
+    if (src->width > hwfc->width || src->height > hwfc->height)
+        return AVERROR(EINVAL);
+
+    map = av_frame_alloc();
+    if (!map)
+        return AVERROR(ENOMEM);
+    map->format = src->format;
+
+    err = vt_map_frame(hwfc, map, dst, AV_HWFRAME_MAP_WRITE | AV_HWFRAME_MAP_OVERWRITE);
+    if (err)
+        goto fail;
+
+    map->width  = src->width;
+    map->height = src->height;
+
+    err = av_frame_copy(map, src);
+    if (err)
+        goto fail;
+
+    err = 0;
+fail:
+    av_frame_free(&map);
+    return err;
+}
+
+static int vt_device_create(AVHWDeviceContext *ctx, const char *device,
+                            AVDictionary *opts, int flags)
+{
+    if (device && device[0]) {
+        av_log(ctx, AV_LOG_ERROR, "Device selection unsupported.\n");
+        return AVERROR_UNKNOWN;
+    }
+
+    return 0;
+}
+
+const HWContextType ff_hwcontext_type_videotoolbox = {
+    .type                 = AV_HWDEVICE_TYPE_VIDEOTOOLBOX,
+    .name                 = "videotoolbox",
+
+    .device_create        = vt_device_create,
+    .frames_get_buffer    = vt_get_buffer,
+    .transfer_get_formats = vt_transfer_get_formats,
+    .transfer_data_to     = vt_transfer_data_to,
+    .transfer_data_from   = vt_transfer_data_from,
+
+    .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_VIDEOTOOLBOX, AV_PIX_FMT_NONE },
+};