lavu: Add DRM hwcontext

1 files changed, 289 insertions, 0 deletions

diff --git a/libavutil/hwcontext_drm.c b/libavutil/hwcontext_drm.c
new file mode 100644
index 0000000000..32cbde82eb
--- /dev/null
+++ b/libavutil/hwcontext_drm.c
@@ -0,0 +1,289 @@
+/*
+ * 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 <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <drm.h>
+#include <xf86drm.h>
+
+#include "avassert.h"
+#include "hwcontext.h"
+#include "hwcontext_drm.h"
+#include "hwcontext_internal.h"
+#include "imgutils.h"
+
+
+static void drm_device_free(AVHWDeviceContext *hwdev)
+{
+    AVDRMDeviceContext *hwctx = hwdev->hwctx;
+
+    close(hwctx->fd);
+}
+
+static int drm_device_create(AVHWDeviceContext *hwdev, const char *device,
+                             AVDictionary *opts, int flags)
+{
+    AVDRMDeviceContext *hwctx = hwdev->hwctx;
+    drmVersionPtr version;
+
+    hwctx->fd = open(device, O_RDWR);
+    if (hwctx->fd < 0)
+        return AVERROR(errno);
+
+    version = drmGetVersion(hwctx->fd);
+    if (!version) {
+        av_log(hwdev, AV_LOG_ERROR, "Failed to get version information "
+               "from %s: probably not a DRM device?\n", device);
+        close(hwctx->fd);
+        return AVERROR(EINVAL);
+    }
+
+    av_log(hwdev, AV_LOG_VERBOSE, "Opened DRM device %s: driver %s "
+           "version %d.%d.%d.\n", device, version->name,
+           version->version_major, version->version_minor,
+           version->version_patchlevel);
+
+    drmFreeVersion(version);
+
+    hwdev->free = &drm_device_free;
+
+    return 0;
+}
+
+static int drm_get_buffer(AVHWFramesContext *hwfc, AVFrame *frame)
+{
+    frame->buf[0] = av_buffer_pool_get(hwfc->pool);
+    if (!frame->buf[0])
+        return AVERROR(ENOMEM);
+
+    frame->data[0] = (uint8_t*)frame->buf[0]->data;
+
+    frame->format = AV_PIX_FMT_DRM_PRIME;
+    frame->width  = hwfc->width;
+    frame->height = hwfc->height;
+
+    return 0;
+}
+
+typedef struct DRMMapping {
+    // Address and length of each mmap()ed region.
+    int nb_regions;
+    void *address[AV_DRM_MAX_PLANES];
+    size_t length[AV_DRM_MAX_PLANES];
+} DRMMapping;
+
+static void drm_unmap_frame(AVHWFramesContext *hwfc,
+                            HWMapDescriptor *hwmap)
+{
+    DRMMapping *map = hwmap->priv;
+    int i;
+
+    for (i = 0; i < map->nb_regions; i++)
+        munmap(map->address[i], map->length[i]);
+
+    av_free(map);
+}
+
+static int drm_map_frame(AVHWFramesContext *hwfc,
+                         AVFrame *dst, const AVFrame *src, int flags)
+{
+    const AVDRMFrameDescriptor *desc = (AVDRMFrameDescriptor*)src->data[0];
+    DRMMapping *map;
+    int err, i, p, plane;
+    int mmap_prot;
+    void *addr;
+
+    map = av_mallocz(sizeof(*map));
+    if (!map)
+        return AVERROR(ENOMEM);
+
+    mmap_prot = 0;
+    if (flags & AV_HWFRAME_MAP_READ)
+        mmap_prot |= PROT_READ;
+    if (flags & AV_HWFRAME_MAP_WRITE)
+        mmap_prot |= PROT_WRITE;
+
+    av_assert0(desc->nb_objects <= AV_DRM_MAX_PLANES);
+    for (i = 0; i < desc->nb_objects; i++) {
+        addr = mmap(NULL, desc->objects[i].size, mmap_prot, MAP_SHARED,
+                    desc->objects[i].fd, 0);
+        if (addr == MAP_FAILED) {
+            err = AVERROR(errno);
+            av_log(hwfc, AV_LOG_ERROR, "Failed to map DRM object %d to "
+                   "memory: %d.\n", desc->objects[i].fd, errno);
+            goto fail;
+        }
+
+        map->address[i] = addr;
+        map->length[i]  = desc->objects[i].size;
+    }
+    map->nb_regions = i;
+
+    plane = 0;
+    for (i = 0; i < desc->nb_layers; i++) {
+        const AVDRMLayerDescriptor *layer = &desc->layers[i];
+        for (p = 0; p < layer->nb_planes; p++) {
+            dst->data[plane] =
+                (uint8_t*)map->address[layer->planes[p].object_index] +
+                                       layer->planes[p].offset;
+            dst->linesize[plane] =     layer->planes[p].pitch;
+            ++plane;
+        }
+    }
+    av_assert0(plane <= AV_DRM_MAX_PLANES);
+
+    dst->width  = src->width;
+    dst->height = src->height;
+
+    err = ff_hwframe_map_create(src->hw_frames_ctx, dst, src,
+                                &drm_unmap_frame, map);
+    if (err < 0)
+        goto fail;
+
+    return 0;
+
+fail:
+    for (i = 0; i < desc->nb_objects; i++) {
+        if (map->address[i])
+            munmap(map->address[i], map->length[i]);
+    }
+    av_free(map);
+    return err;
+}
+
+static int drm_transfer_get_formats(AVHWFramesContext *ctx,
+                                    enum AVHWFrameTransferDirection dir,
+                                    enum AVPixelFormat **formats)
+{
+    enum AVPixelFormat *pix_fmts;
+
+    pix_fmts = av_malloc_array(2, sizeof(*pix_fmts));
+    if (!pix_fmts)
+        return AVERROR(ENOMEM);
+
+    pix_fmts[0] = ctx->sw_format;
+    pix_fmts[1] = AV_PIX_FMT_NONE;
+
+    *formats = pix_fmts;
+    return 0;
+}
+
+static int drm_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 = drm_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 drm_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 = drm_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 drm_map_from(AVHWFramesContext *hwfc, AVFrame *dst,
+                        const AVFrame *src, int flags)
+{
+    int err;
+
+    if (hwfc->sw_format != dst->format)
+        return AVERROR(ENOSYS);
+
+    err = drm_map_frame(hwfc, dst, src, flags);
+    if (err)
+        return err;
+
+    err = av_frame_copy_props(dst, src);
+    if (err)
+        return err;
+
+    return 0;
+}
+
+const HWContextType ff_hwcontext_type_drm = {
+    .type                   = AV_HWDEVICE_TYPE_DRM,
+    .name                   = "DRM",
+
+    .device_hwctx_size      = sizeof(AVDRMDeviceContext),
+
+    .device_create          = &drm_device_create,
+
+    .frames_get_buffer      = &drm_get_buffer,
+
+    .transfer_get_formats   = &drm_transfer_get_formats,
+    .transfer_data_to       = &drm_transfer_data_to,
+    .transfer_data_from     = &drm_transfer_data_from,
+    .map_from               = &drm_map_from,
+
+    .pix_fmts = (const enum AVPixelFormat[]) {
+        AV_PIX_FMT_DRM_PRIME,
+        AV_PIX_FMT_NONE
+    },
+};