[FFmpeg-cvslog] hwcontext: Hardware frame mapping
Mark Thompson
git at videolan.org
Thu Mar 30 11:38:59 EEST 2017
ffmpeg | branch: master | Mark Thompson <sw at jkqxz.net> | Tue Oct 25 20:38:47 2016 +0100| [d06aa24ba583ad08025da9e1b29afcd8218ff9b0] | committer: Mark Thompson
hwcontext: Hardware frame mapping
Adds the new av_hwframe_map() function, which allows mapping between
hardware frames and normal memory, along with internal support for
implementing it.
Also adds av_hwframe_ctx_create_derived(), for creating a hardware
frames context associated with one device using frames mapped from
another by some hardware-specific means.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d06aa24ba583ad08025da9e1b29afcd8218ff9b0
---
doc/APIchanges | 4 +
libavutil/hwcontext.c | 239 +++++++++++++++++++++++++++++++++++++++--
libavutil/hwcontext.h | 87 +++++++++++++++
libavutil/hwcontext_internal.h | 40 +++++++
libavutil/version.h | 2 +-
5 files changed, 365 insertions(+), 7 deletions(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index 011ff0a..735b947 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -13,6 +13,10 @@ libavutil: 2015-08-28
API changes, most recent first:
+2016-xx-xx - xxxxxxx - lavu 55.27.0 - hwcontext.h
+ Add av_hwframe_map() and associated AV_HWFRAME_MAP_* flags.
+ Add av_hwframe_ctx_create_derived().
+
2016-xx-xx - xxxxxxx - lavu 55.25.0 - pixfmt.h
Add AV_PIX_FMT_GBRAP12(LE/BE).
diff --git a/libavutil/hwcontext.c b/libavutil/hwcontext.c
index b47ef44..83f733e 100644
--- a/libavutil/hwcontext.c
+++ b/libavutil/hwcontext.c
@@ -157,14 +157,19 @@ static void hwframe_ctx_free(void *opaque, uint8_t *data)
{
AVHWFramesContext *ctx = (AVHWFramesContext*)data;
- if (ctx->internal->pool_internal)
- av_buffer_pool_uninit(&ctx->internal->pool_internal);
+ if (ctx->internal->source_frames) {
+ av_buffer_unref(&ctx->internal->source_frames);
- if (ctx->internal->hw_type->frames_uninit)
- ctx->internal->hw_type->frames_uninit(ctx);
+ } else {
+ if (ctx->internal->pool_internal)
+ av_buffer_pool_uninit(&ctx->internal->pool_internal);
- if (ctx->free)
- ctx->free(ctx);
+ if (ctx->internal->hw_type->frames_uninit)
+ ctx->internal->hw_type->frames_uninit(ctx);
+
+ if (ctx->free)
+ ctx->free(ctx);
+ }
av_buffer_unref(&ctx->device_ref);
@@ -266,6 +271,11 @@ int av_hwframe_ctx_init(AVBufferRef *ref)
const enum AVPixelFormat *pix_fmt;
int ret;
+ if (ctx->internal->source_frames) {
+ /* A derived frame context is already initialised. */
+ return 0;
+ }
+
/* validate the pixel format */
for (pix_fmt = ctx->internal->hw_type->pix_fmts; *pix_fmt != AV_PIX_FMT_NONE; pix_fmt++) {
if (*pix_fmt == ctx->format)
@@ -396,6 +406,35 @@ int av_hwframe_get_buffer(AVBufferRef *hwframe_ref, AVFrame *frame, int flags)
AVHWFramesContext *ctx = (AVHWFramesContext*)hwframe_ref->data;
int ret;
+ if (ctx->internal->source_frames) {
+ // This is a derived frame context, so we allocate in the source
+ // and map the frame immediately.
+ AVFrame *src_frame;
+
+ src_frame = av_frame_alloc();
+ if (!src_frame)
+ return AVERROR(ENOMEM);
+
+ ret = av_hwframe_get_buffer(ctx->internal->source_frames,
+ src_frame, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = av_hwframe_map(frame, src_frame, 0);
+ if (ret) {
+ av_log(ctx, AV_LOG_ERROR, "Failed to map frame into derived "
+ "frame context: %d.\n", ret);
+ av_frame_free(&src_frame);
+ return ret;
+ }
+
+ // Free the source frame immediately - the mapped frame still
+ // contains a reference to it.
+ av_frame_free(&src_frame);
+
+ return 0;
+ }
+
if (!ctx->internal->hw_type->frames_get_buffer)
return AVERROR(ENOSYS);
@@ -495,3 +534,191 @@ fail:
*pdevice_ref = NULL;
return ret;
}
+
+static void ff_hwframe_unmap(void *opaque, uint8_t *data)
+{
+ HWMapDescriptor *hwmap = (HWMapDescriptor*)data;
+ AVHWFramesContext *ctx = opaque;
+
+ if (hwmap->unmap)
+ hwmap->unmap(ctx, hwmap);
+
+ av_frame_free(&hwmap->source);
+
+ av_buffer_unref(&hwmap->hw_frames_ctx);
+
+ av_free(hwmap);
+}
+
+int ff_hwframe_map_create(AVBufferRef *hwframe_ref,
+ AVFrame *dst, const AVFrame *src,
+ void (*unmap)(AVHWFramesContext *ctx,
+ HWMapDescriptor *hwmap),
+ void *priv)
+{
+ AVHWFramesContext *ctx = (AVHWFramesContext*)hwframe_ref->data;
+ HWMapDescriptor *hwmap;
+ int ret;
+
+ hwmap = av_mallocz(sizeof(*hwmap));
+ if (!hwmap) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ hwmap->source = av_frame_alloc();
+ if (!hwmap->source) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ ret = av_frame_ref(hwmap->source, src);
+ if (ret < 0)
+ goto fail;
+
+ hwmap->hw_frames_ctx = av_buffer_ref(hwframe_ref);
+ if (!hwmap->hw_frames_ctx) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ hwmap->unmap = unmap;
+ hwmap->priv = priv;
+
+ dst->buf[0] = av_buffer_create((uint8_t*)hwmap, sizeof(*hwmap),
+ &ff_hwframe_unmap, ctx, 0);
+ if (!dst->buf[0]) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ if (hwmap) {
+ av_buffer_unref(&hwmap->hw_frames_ctx);
+ av_frame_free(&hwmap->source);
+ }
+ av_free(hwmap);
+ return ret;
+}
+
+int av_hwframe_map(AVFrame *dst, const AVFrame *src, int flags)
+{
+ AVHWFramesContext *src_frames, *dst_frames;
+ HWMapDescriptor *hwmap;
+ int ret;
+
+ if (src->hw_frames_ctx && dst->hw_frames_ctx) {
+ src_frames = (AVHWFramesContext*)src->hw_frames_ctx->data;
+ dst_frames = (AVHWFramesContext*)dst->hw_frames_ctx->data;
+
+ if ((src_frames == dst_frames &&
+ src->format == dst_frames->sw_format &&
+ dst->format == dst_frames->format) ||
+ (src_frames->internal->source_frames &&
+ src_frames->internal->source_frames->data ==
+ (uint8_t*)dst_frames)) {
+ // This is an unmap operation. We don't need to directly
+ // do anything here other than fill in the original frame,
+ // because the real unmap will be invoked when the last
+ // reference to the mapped frame disappears.
+ if (!src->buf[0]) {
+ av_log(src_frames, AV_LOG_ERROR, "Invalid mapping "
+ "found when attempting unmap.\n");
+ return AVERROR(EINVAL);
+ }
+ hwmap = (HWMapDescriptor*)src->buf[0]->data;
+ av_frame_unref(dst);
+ return av_frame_ref(dst, hwmap->source);
+ }
+ }
+
+ if (src->hw_frames_ctx) {
+ src_frames = (AVHWFramesContext*)src->hw_frames_ctx->data;
+
+ if (src_frames->format == src->format &&
+ src_frames->internal->hw_type->map_from) {
+ ret = src_frames->internal->hw_type->map_from(src_frames,
+ dst, src, flags);
+ if (ret != AVERROR(ENOSYS))
+ return ret;
+ }
+ }
+
+ if (dst->hw_frames_ctx) {
+ dst_frames = (AVHWFramesContext*)dst->hw_frames_ctx->data;
+
+ if (dst_frames->format == dst->format &&
+ dst_frames->internal->hw_type->map_to) {
+ ret = dst_frames->internal->hw_type->map_to(dst_frames,
+ dst, src, flags);
+ if (ret != AVERROR(ENOSYS))
+ return ret;
+ }
+ }
+
+ return AVERROR(ENOSYS);
+}
+
+int av_hwframe_ctx_create_derived(AVBufferRef **derived_frame_ctx,
+ enum AVPixelFormat format,
+ AVBufferRef *derived_device_ctx,
+ AVBufferRef *source_frame_ctx,
+ int flags)
+{
+ AVBufferRef *dst_ref = NULL;
+ AVHWFramesContext *dst = NULL;
+ AVHWFramesContext *src = (AVHWFramesContext*)source_frame_ctx->data;
+ int ret;
+
+ if (src->internal->source_frames) {
+ AVHWFramesContext *src_src =
+ (AVHWFramesContext*)src->internal->source_frames->data;
+ AVHWDeviceContext *dst_dev =
+ (AVHWDeviceContext*)derived_device_ctx->data;
+
+ if (src_src->device_ctx == dst_dev) {
+ // This is actually an unmapping, so we just return a
+ // reference to the source frame context.
+ *derived_frame_ctx =
+ av_buffer_ref(src->internal->source_frames);
+ if (!*derived_frame_ctx) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ return 0;
+ }
+ }
+
+ dst_ref = av_hwframe_ctx_alloc(derived_device_ctx);
+ if (!dst_ref) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ dst = (AVHWFramesContext*)dst_ref->data;
+
+ dst->format = format;
+ dst->sw_format = src->sw_format;
+ dst->width = src->width;
+ dst->height = src->height;
+
+ dst->internal->source_frames = av_buffer_ref(source_frame_ctx);
+ if (!dst->internal->source_frames) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ ret = av_hwframe_ctx_init(dst_ref);
+ if (ret)
+ goto fail;
+
+ *derived_frame_ctx = dst_ref;
+ return 0;
+
+fail:
+ if (dst)
+ av_buffer_unref(&dst->internal->source_frames);
+ av_buffer_unref(&dst_ref);
+ return ret;
+}
diff --git a/libavutil/hwcontext.h b/libavutil/hwcontext.h
index 0b12fe2..4067ff1 100644
--- a/libavutil/hwcontext.h
+++ b/libavutil/hwcontext.h
@@ -434,4 +434,91 @@ AVHWFramesConstraints *av_hwdevice_get_hwframe_constraints(AVBufferRef *ref,
*/
void av_hwframe_constraints_free(AVHWFramesConstraints **constraints);
+
+/**
+ * Flags to apply to frame mappings.
+ */
+enum {
+ /**
+ * The mapping must be readable.
+ */
+ AV_HWFRAME_MAP_READ = 1 << 0,
+ /**
+ * The mapping must be writeable.
+ */
+ AV_HWFRAME_MAP_WRITE = 1 << 1,
+ /**
+ * The mapped frame will be overwritten completely in subsequent
+ * operations, so the current frame data need not be loaded. Any values
+ * which are not overwritten are unspecified.
+ */
+ AV_HWFRAME_MAP_OVERWRITE = 1 << 2,
+ /**
+ * The mapping must be direct. That is, there must not be any copying in
+ * the map or unmap steps. Note that performance of direct mappings may
+ * be much lower than normal memory.
+ */
+ AV_HWFRAME_MAP_DIRECT = 1 << 3,
+};
+
+/**
+ * Map a hardware frame.
+ *
+ * This has a number of different possible effects, depending on the format
+ * and origin of the src and dst frames. On input, src should be a usable
+ * frame with valid buffers and dst should be blank (typically as just created
+ * by av_frame_alloc()). src should have an associated hwframe context, and
+ * dst may optionally have a format and associated hwframe context.
+ *
+ * If src was created by mapping a frame from the hwframe context of dst,
+ * then this function undoes the mapping - dst is replaced by a reference to
+ * the frame that src was originally mapped from.
+ *
+ * If both src and dst have an associated hwframe context, then this function
+ * attempts to map the src frame from its hardware context to that of dst and
+ * then fill dst with appropriate data to be usable there. This will only be
+ * possible if the hwframe contexts and associated devices are compatible -
+ * given compatible devices, av_hwframe_ctx_create_derived() can be used to
+ * create a hwframe context for dst in which mapping should be possible.
+ *
+ * If src has a hwframe context but dst does not, then the src frame is
+ * mapped to normal memory and should thereafter be usable as a normal frame.
+ * If the format is set on dst, then the mapping will attempt to create dst
+ * with that format and fail if it is not possible. If format is unset (is
+ * AV_PIX_FMT_NONE) then dst will be mapped with whatever the most appropriate
+ * format to use is (probably the sw_format of the src hwframe context).
+ *
+ * A return value of AVERROR(ENOSYS) indicates that the mapping is not
+ * possible with the given arguments and hwframe setup, while other return
+ * values indicate that it failed somehow.
+ *
+ * @param dst Destination frame, to contain the mapping.
+ * @param src Source frame, to be mapped.
+ * @param flags Some combination of AV_HWFRAME_MAP_* flags.
+ * @return Zero on success, negative AVERROR code on failure.
+ */
+int av_hwframe_map(AVFrame *dst, const AVFrame *src, int flags);
+
+
+/**
+ * Create and initialise an AVHWFramesContext as a mapping of another existing
+ * AVHWFramesContext on a different device.
+ *
+ * av_hwframe_ctx_init() should not be called after this.
+ *
+ * @param derived_frame_ctx On success, a reference to the newly created
+ * AVHWFramesContext.
+ * @param derived_device_ctx A reference to the device to create the new
+ * AVHWFramesContext on.
+ * @param source_frame_ctx A reference to an existing AVHWFramesContext
+ * which will be mapped to the derived context.
+ * @param flags Currently unused; should be set to zero.
+ * @return Zero on success, negative AVERROR code on failure.
+ */
+int av_hwframe_ctx_create_derived(AVBufferRef **derived_frame_ctx,
+ enum AVPixelFormat format,
+ AVBufferRef *derived_device_ctx,
+ AVBufferRef *source_frame_ctx,
+ int flags);
+
#endif /* AVUTIL_HWCONTEXT_H */
diff --git a/libavutil/hwcontext_internal.h b/libavutil/hwcontext_internal.h
index a391e25..11e3a68 100644
--- a/libavutil/hwcontext_internal.h
+++ b/libavutil/hwcontext_internal.h
@@ -85,6 +85,11 @@ typedef struct HWContextType {
const AVFrame *src);
int (*transfer_data_from)(AVHWFramesContext *ctx, AVFrame *dst,
const AVFrame *src);
+
+ int (*map_to)(AVHWFramesContext *ctx, AVFrame *dst,
+ const AVFrame *src, int flags);
+ int (*map_from)(AVHWFramesContext *ctx, AVFrame *dst,
+ const AVFrame *src, int flags);
} HWContextType;
struct AVHWDeviceInternal {
@@ -97,8 +102,43 @@ struct AVHWFramesInternal {
void *priv;
AVBufferPool *pool_internal;
+
+ /**
+ * For a derived context, a reference to the original frames
+ * context it was derived from.
+ */
+ AVBufferRef *source_frames;
};
+typedef struct HWMapDescriptor {
+ /**
+ * A reference to the original source of the mapping.
+ */
+ AVFrame *source;
+ /**
+ * A reference to the hardware frames context in which this
+ * mapping was made. May be the same as source->hw_frames_ctx,
+ * but need not be.
+ */
+ AVBufferRef *hw_frames_ctx;
+ /**
+ * Unmap function.
+ */
+ void (*unmap)(AVHWFramesContext *ctx,
+ struct HWMapDescriptor *hwmap);
+ /**
+ * Hardware-specific private data associated with the mapping.
+ */
+ void *priv;
+} HWMapDescriptor;
+
+int ff_hwframe_map_create(AVBufferRef *hwframe_ref,
+ AVFrame *dst, const AVFrame *src,
+ void (*unmap)(AVHWFramesContext *ctx,
+ HWMapDescriptor *hwmap),
+ void *priv);
+
+
extern const HWContextType ff_hwcontext_type_cuda;
extern const HWContextType ff_hwcontext_type_dxva2;
extern const HWContextType ff_hwcontext_type_qsv;
diff --git a/libavutil/version.h b/libavutil/version.h
index c1cfcbb..9287a0b 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -54,7 +54,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 55
-#define LIBAVUTIL_VERSION_MINOR 26
+#define LIBAVUTIL_VERSION_MINOR 27
#define LIBAVUTIL_VERSION_MICRO 0
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
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