[FFmpeg-devel] [PATCH v2 1/2] lavu: Add DRM hwcontext

Mark Thompson sw at jkqxz.net
Thu Jul 6 02:02:08 EEST 2017


---
Updated following discussion:
* Back to using nested arrays.
* Documentation improved.
* Configure option now called libdrm.
* Other minor fixups.


 configure                      |   3 +
 libavutil/Makefile             |   2 +
 libavutil/hwcontext.c          |   4 +
 libavutil/hwcontext.h          |   1 +
 libavutil/hwcontext_drm.c      | 294 +++++++++++++++++++++++++++++++++++++++++
 libavutil/hwcontext_drm.h      | 166 +++++++++++++++++++++++
 libavutil/hwcontext_internal.h |   1 +
 libavutil/pixdesc.c            |   4 +
 libavutil/pixfmt.h             |   4 +
 9 files changed, 479 insertions(+)
 create mode 100644 libavutil/hwcontext_drm.c
 create mode 100644 libavutil/hwcontext_drm.h

diff --git a/configure b/configure
index 9509bdf09c..3225c3cca7 100755
--- a/configure
+++ b/configure
@@ -298,6 +298,7 @@ External library support:
   --disable-cuvid          disable Nvidia CUVID support [autodetect]
   --disable-d3d11va        disable Microsoft Direct3D 11 video acceleration code [autodetect]
   --disable-dxva2          disable Microsoft DirectX 9 video acceleration code [autodetect]
+  --enable-libdrm          enable DRM code (Linux) [no]
   --enable-libmfx          enable Intel MediaSDK (AKA Quick Sync Video) code via libmfx [no]
   --enable-libnpp          enable Nvidia Performance Primitives-based code [no]
   --enable-mmal            enable Broadcom Multi-Media Abstraction Layer (Raspberry Pi) via MMAL [no]
@@ -1539,6 +1540,7 @@ EXTERNAL_LIBRARY_LIST="
     libcaca
     libcelt
     libdc1394
+    libdrm
     libflite
     libfontconfig
     libfreetype
@@ -5797,6 +5799,7 @@ enabled libcelt           && require libcelt celt/celt.h celt_decode -lcelt0 &&
                                die "ERROR: libcelt must be installed and version must be >= 0.11.0."; }
 enabled libcaca           && require_pkg_config caca caca.h caca_create_canvas
 enabled libdc1394         && require_pkg_config libdc1394-2 dc1394/dc1394.h dc1394_new
+enabled libdrm            && require_pkg_config libdrm xf86drm.h drmGetVersion
 enabled libfdk_aac        && { use_pkg_config fdk-aac "fdk-aac/aacenc_lib.h" aacEncOpen ||
                                { require libfdk_aac fdk-aac/aacenc_lib.h aacEncOpen -lfdk-aac &&
                                  warn "using libfdk without pkg-config"; } }
diff --git a/libavutil/Makefile b/libavutil/Makefile
index 4fe81fdd07..991b2f3fbd 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -33,6 +33,7 @@ HEADERS = adler32.h                                                     \
           hmac.h                                                        \
           hwcontext.h                                                   \
           hwcontext_cuda.h                                              \
+          hwcontext_drm.h                                               \
           hwcontext_dxva2.h                                             \
           hwcontext_qsv.h                                               \
           hwcontext_vaapi.h                                             \
@@ -158,6 +159,7 @@ OBJS-$(!HAVE_ATOMICS_NATIVE)            += atomic.o                     \
 OBJS-$(CONFIG_CUDA)                     += hwcontext_cuda.o
 OBJS-$(CONFIG_DXVA2)                    += hwcontext_dxva2.o
 OBJS-$(CONFIG_QSV)                   += hwcontext_qsv.o
+OBJS-$(CONFIG_LIBDRM)                   += hwcontext_drm.o
 OBJS-$(CONFIG_LZO)                      += lzo.o
 OBJS-$(CONFIG_OPENCL)                   += opencl.o opencl_internal.o
 OBJS-$(CONFIG_VAAPI)                    += hwcontext_vaapi.o
diff --git a/libavutil/hwcontext.c b/libavutil/hwcontext.c
index 5a22194716..e40ceb12a1 100644
--- a/libavutil/hwcontext.c
+++ b/libavutil/hwcontext.c
@@ -32,6 +32,9 @@ static const HWContextType *const hw_table[] = {
 #if CONFIG_CUDA
     &ff_hwcontext_type_cuda,
 #endif
+#if CONFIG_LIBDRM
+    &ff_hwcontext_type_drm,
+#endif
 #if CONFIG_DXVA2
     &ff_hwcontext_type_dxva2,
 #endif
@@ -52,6 +55,7 @@ static const HWContextType *const hw_table[] = {
 
 static const char *const hw_type_names[] = {
     [AV_HWDEVICE_TYPE_CUDA]   = "cuda",
+    [AV_HWDEVICE_TYPE_DRM]    = "drm",
     [AV_HWDEVICE_TYPE_DXVA2]  = "dxva2",
     [AV_HWDEVICE_TYPE_QSV]    = "qsv",
     [AV_HWDEVICE_TYPE_VAAPI]  = "vaapi",
diff --git a/libavutil/hwcontext.h b/libavutil/hwcontext.h
index edf12cc631..fe7613b379 100644
--- a/libavutil/hwcontext.h
+++ b/libavutil/hwcontext.h
@@ -32,6 +32,7 @@ enum AVHWDeviceType {
     AV_HWDEVICE_TYPE_QSV,
     AV_HWDEVICE_TYPE_VIDEOTOOLBOX,
     AV_HWDEVICE_TYPE_NONE,
+    AV_HWDEVICE_TYPE_DRM,
 };
 
 typedef struct AVHWDeviceInternal AVHWDeviceInternal;
diff --git a/libavutil/hwcontext_drm.c b/libavutil/hwcontext_drm.c
new file mode 100644
index 0000000000..c6be3295f9
--- /dev/null
+++ b/libavutil/hwcontext_drm.c
@@ -0,0 +1,294 @@
+/*
+ * 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 <fcntl.h>
+#include <sys/mman.h>
+#if HAVE_UNISTD_H
+#   include <unistd.h>
+#endif
+
+#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_UNKNOWN;
+
+    version = drmGetVersion(hwctx->fd);
+    if (!version) {
+        av_log(hwdev, AV_LOG_ERROR, "Failed to DRM 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++) {
+        if (map->address[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)
+        return err;
+
+    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
+    },
+};
diff --git a/libavutil/hwcontext_drm.h b/libavutil/hwcontext_drm.h
new file mode 100644
index 0000000000..2e225451e1
--- /dev/null
+++ b/libavutil/hwcontext_drm.h
@@ -0,0 +1,166 @@
+/*
+ * 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
+ */
+
+#ifndef AVUTIL_HWCONTEXT_DRM_H
+#define AVUTIL_HWCONTEXT_DRM_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/**
+ * @file
+ * API-specific header for AV_HWDEVICE_TYPE_DRM.
+ *
+ * Internal frame allocation is not currently supported - all frames
+ * must be allocated by the user.  Thus AVHWFramesContext is always
+ * NULL, though this may change if support for frame allocation is
+ * added in future.
+ */
+
+enum {
+    /**
+     * The maximum number of layers/planes in a DRM frame.
+     */
+    AV_DRM_MAX_PLANES = 4
+};
+
+/**
+ * DRM object descriptor.
+ *
+ * Describes a single DRM object, addressing it as a PRIME file
+ * descriptor.
+ */
+typedef struct AVDRMObjectDescriptor {
+    /**
+     * DRM PRIME fd for the object.
+     */
+    int fd;
+    /**
+     * Total size of the object.
+     *
+     * (This includes any parts not which do not contain image data.)
+     */
+    size_t size;
+    /**
+     * Format modifier applied to the object (DRM_FORMAT_MOD_*).
+     */
+    uint64_t format_modifier;
+} AVDRMObjectDescriptor;
+
+/**
+ * DRM plane descriptor.
+ *
+ * Describes a single plane of a layer, which is contained within
+ * a single object.
+ */
+typedef struct AVDRMPlaneDescriptor {
+    /**
+     * Index of the object containing this plane in the objects
+     * array of the enclosing frame descriptor.
+     */
+    int object_index;
+    /**
+     * Offset within that object of this plane.
+     */
+    ptrdiff_t offset;
+    /**
+     * Pitch (linesize) of this plane.
+     */
+    ptrdiff_t pitch;
+} AVDRMPlaneDescriptor;
+
+/**
+ * DRM layer descriptor.
+ *
+ * Describes a single layer within a frame.  This has the structure
+ * defined by its format, and will contain one or more planes.
+ */
+typedef struct AVDRMLayerDescriptor {
+    /**
+     * Format of the layer (DRM_FORMAT_*).
+     */
+    uint32_t format;
+    /**
+     * Number of planes in the layer.
+     *
+     * This must match the number of planes required by format.
+     */
+    int nb_planes;
+    /**
+     * Array of planes in this layer.
+     */
+    AVDRMPlaneDescriptor planes[AV_DRM_MAX_PLANES];
+} AVDRMLayerDescriptor;
+
+/**
+ * DRM frame descriptor.
+ *
+ * This is used as the data pointer for AV_PIX_FMT_DRM_PRIME frames.
+ * It is also used by user-allocated frame pools - allocating in
+ * AVHWFramesContext.pool must return AVBufferRefs which contain
+ * an object of this type.
+ *
+ * The fields of this structure should be set such it can be
+ * imported directly by EGL using the EGL_EXT_image_dma_buf_import
+ * and EGL_EXT_image_dma_buf_import_modifiers extensions.
+ * (Note that the exact layout of a particular format may vary between
+ * platforms - we only specify that the same platform should be able
+ * to import it.)
+ *
+ * The total number of planes must not exceed AV_DRM_MAX_PLANES, and
+ * the order of the planes by increasing layer index followed by
+ * increasing plane index must be the same as the order which would
+ * be used for the data pointers in the equivalent software format.
+ */
+typedef struct AVDRMFrameDescriptor {
+    /**
+     * Number of DRM objects making up this frame.
+     */
+    int nb_objects;
+    /**
+     * Array of objects making up the frame.
+     */
+    AVDRMObjectDescriptor objects[AV_DRM_MAX_PLANES];
+    /**
+     * Number of layers in the frame.
+     */
+    int nb_layers;
+    /**
+     * Array of layers in the frame.
+     */
+    AVDRMLayerDescriptor layers[AV_DRM_MAX_PLANES];
+} AVDRMFrameDescriptor;
+
+/**
+ * DRM device.
+ *
+ * Allocated as AVHWDeviceContext.hwctx.
+ */
+typedef struct AVDRMDeviceContext {
+    /**
+     * File descriptor of DRM device.
+     *
+     * This is used as the device to create frames on, and may also be
+     * used in some derivation and mapping operations.
+     *
+     * If no device is required, set to -1.
+     */
+    int fd;
+} AVDRMDeviceContext;
+
+#endif /* AVUTIL_HWCONTEXT_DRM_H */
diff --git a/libavutil/hwcontext_internal.h b/libavutil/hwcontext_internal.h
index 68f78c0a1f..314c3656a7 100644
--- a/libavutil/hwcontext_internal.h
+++ b/libavutil/hwcontext_internal.h
@@ -158,6 +158,7 @@ int ff_hwframe_map_create(AVBufferRef *hwframe_ref,
 
 
 extern const HWContextType ff_hwcontext_type_cuda;
+extern const HWContextType ff_hwcontext_type_drm;
 extern const HWContextType ff_hwcontext_type_dxva2;
 extern const HWContextType ff_hwcontext_type_qsv;
 extern const HWContextType ff_hwcontext_type_vaapi;
diff --git a/libavutil/pixdesc.c b/libavutil/pixdesc.c
index d4a7a8ba3b..bc1142d571 100644
--- a/libavutil/pixdesc.c
+++ b/libavutil/pixdesc.c
@@ -2158,6 +2158,10 @@ static const AVPixFmtDescriptor av_pix_fmt_descriptors[AV_PIX_FMT_NB] = {
         .flags = AV_PIX_FMT_FLAG_BE | AV_PIX_FMT_FLAG_PLANAR |
                  AV_PIX_FMT_FLAG_RGB | AV_PIX_FMT_FLAG_ALPHA,
     },
+    [AV_PIX_FMT_DRM_PRIME] = {
+        .name = "drm_prime",
+        .flags = AV_PIX_FMT_FLAG_HWACCEL,
+    },
 };
 #if FF_API_PLUS1_MINUS1
 FF_ENABLE_DEPRECATION_WARNINGS
diff --git a/libavutil/pixfmt.h b/libavutil/pixfmt.h
index 6b7eea8c4e..5a6a732061 100644
--- a/libavutil/pixfmt.h
+++ b/libavutil/pixfmt.h
@@ -314,6 +314,10 @@ enum AVPixelFormat {
     AV_PIX_FMT_P016LE, ///< like NV12, with 16bpp per component, little-endian
     AV_PIX_FMT_P016BE, ///< like NV12, with 16bpp per component, big-endian
 
+    // DRM-managed buffers exposed through PRIME buffer sharing.
+    // data[0] points to an AVDRMFrameDescriptor.
+    AV_PIX_FMT_DRM_PRIME,
+
     AV_PIX_FMT_NB         ///< number of pixel formats, DO NOT USE THIS if you want to link with shared libav* because the number of formats might differ between versions
 };
 
-- 
2.11.0



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