Add support for Tegra V4L2 VDA

content/common/gpu/media/tegra_v4l2_video_device.cc

Index: content/common/gpu/media/tegra_v4l2_video_device.cc
diff --git a/content/common/gpu/media/tegra_v4l2_video_device.cc b/content/common/gpu/media/tegra_v4l2_video_device.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b7b7cddd14b0749d0719eeab03b1655814c0eeac
--- /dev/null
+++ b/content/common/gpu/media/tegra_v4l2_video_device.cc
@@ -0,0 +1,172 @@
+#include <dlfcn.h>

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

missing copyright header

+#include <errno.h>
+#include <fcntl.h>
+#include <libdrm/drm_fourcc.h>

[Pawel Osciak, 2014/02/10 06:36:17]

Not needed?

+#include <linux/videodev2.h>
+#include <poll.h>

[Pawel Osciak, 2014/02/10 06:36:17]

Not needed.

+#include <sys/eventfd.h>

[Pawel Osciak, 2014/02/10 06:36:17]

Not needed.

+#include <sys/ioctl.h>
+#include <sys/mman.h>

[Pawel Osciak, 2014/02/10 06:36:17]

Not needed?

Please clean up the headers in this file to a minimal set of required ones only
(also applies to the Chrome headers below).

+
+#include "base/bind.h"
+#include "base/debug/trace_event.h"
+#include "base/memory/shared_memory.h"
+#include "base/message_loop/message_loop.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "base/posix/eintr_wrapper.h"
+#include "content/common/gpu/media/tegra_v4l2_video_device.h"
+#include "ui/gl/gl_bindings.h"
+
+namespace content {
+
+namespace {
+const char kDevice[] = "/dev/video0";

[Pawel Osciak, 2014/02/10 06:36:17]

Is this is the codec device exposed by Tegra kernel driver?

You can't assume it will be this on all configurations.
Please use udev rules to create a codec specific device (see Exynos example at
https://chromium.googlesource.com/chromiumos/overlays/board-overlays/+/HEAD/o...)

[shivdasp, 2014/02/10 13:31:17]

This is a v4l2 decoder device name which we use to initialize a decoder context
within the libtegrav4l2 library.
This can be anything really as long as decoder and encoder device names are
different since we do not open a v4l2 video device underneath. Libtegrav4l2 is
really a pseudo implementation. I can change it /dev/tegra-dec and
/dev/tegra-enc for it to mean tegra specific.

On 2014/02/10 06:36:17, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/12 09:15:13]

Which device is actually being used? Does the library just talk to DRM driver
via custom ioctls?

[shivdasp, 2014/02/12 10:11:55]

This library internally talks to MM layer which talks to the device
(/dev/tegra_avpchannel) which is the nvavp driver.

On 2014/02/12 09:15:13, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/13 10:42:54]

This means you will have to add it to sandbox rules in Chrome, right? So the
library should actually use the device path string provided from Chrome to
Open() and not have the string hardcoded in the library please.

[shivdasp, 2014/02/14 03:06:45]

Yes /dev/tegra_avpchannel will be added in the sandbox whitelist for now.
Work is in progress to make this sandbox friendly in our MM stack. Most probably
by the time we get this change merged we should have completed it so even
whitelisting may not be required. In worst case we will whitelist it sandbox
code.

As I said earlier this "device name" sent to the library is just dummy for the
libtegrav4l2 to create a decoder instance. It just has to be different than the
encoder "device name".
Shall I just keep it "tegra_dec" and "tegra_enc" to not mislead it for something
like a true v4l2 device name ?

On 2014/02/13 10:42:54, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/14 07:36:10]

Why it may not be required? How else would it be accessible if it's not
whitelisted?
Please, the library has to open the device with the same name as this method
provides to it.
 

[shivdasp, 2014/02/14 09:18:58]

Whitelisted will not be required because of pre-acquire the resources (including
open() for /dev/tegra_avpchannel) in the libtegrav4l2.so which we load before
the sandbox will kick in.
Hence the only place we will have this device name will be in TegraV4L2Device
which will be used to open the decoder instance. (The pre-opened fd will be
used).
Okay I will keep the same device name (/dev/tegra_avpchannel).

On 2014/02/14 07:36:10, Pawel Osciak wrote:

+}
+
+TegraV4L2Device::TegraV4L2Device(EGLContext egl_context)
+    : device_fd_(-1), egl_context_(egl_context) {}
+
+TegraV4L2Device::~TegraV4L2Device() {
+  if (device_fd_ != -1) {
+    TegraV4L2Close(device_fd_);
+    device_fd_ = -1;
+  }
+}
+
+int TegraV4L2Device::Ioctl(int flags, void* arg) {
+  return TegraV4L2Ioctl(device_fd_, flags, arg);
+}
+
+bool TegraV4L2Device::Poll(bool poll_device, bool* event_pending) {
+  if (TegraV4L2Poll(device_fd_, poll_device, event_pending) == -1) {
+    DLOG(ERROR) << "TegraV4L2Poll returned -1 ";
+    return false;
+  }
+  return true;
+}
+
+void* TegraV4L2Device::Mmap(void* addr,
+                            unsigned int len,
+                            int prot,
+                            int flags,
+                            unsigned int offset) {
+  // No real mmap for tegrav4l2 device, the offset is itself the address.
+  return (void*)offset;

[Pawel Osciak, 2014/02/10 06:36:17]

QUERYBUFS from V4L2VDA is used to acquire offsets for mmap, but from
CreateEGLImage to pass them for texture binding to the library? I'm guessing
that this works, because for the former you call QUERYBUFS with OUTPUT buffer,
while in the latter you call it with CAPTURE?

Please don't do this. Suggested changes for EGLImages in my comments below. 

As for mmap, how (and from what) is the memory mapping actually acquired for the
buffer in the library? Why do this on QUERYBUFS and not on Mmap()? How is it
managed and when it is destroyed? 

[shivdasp, 2014/02/10 13:31:17]

When REQBUFS is called for OUTPUT_PLANE, the library creates internal buffers
which can be shared with the AVP for decoding. AVP is a video processor which
runs the firmware that actually does all the decoding. While creating this
buffers, they are already mmapped to get a virtual address. The library returns
this address in QUERYBUF API. Hence there is not real need for mmap.
When REQBUFS with 0 is called on OUTPUT_PLANE, these buffers are internally
unmapped and destroyed.
I will explain the need for CreateEGLImage in later comments.

On 2014/02/10 06:36:17, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/12 09:15:13]

The library must be using some kind of an mmap call to get a mapping though.
Would it be possible to move it to be done on this call, as expected?

Also, how will this work for VEA, where CAPTURE buffers need to be mapped
instead?

[shivdasp, 2014/02/12 10:11:55]

Okay I will add Mmap and Munmap calls to the library and have it return the
appropriate value internally.

On 2014/02/12 09:15:13, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/13 10:42:54]

Great. Thank you!

+}
+
+void TegraV4L2Device::Munmap(void* addr, unsigned int len) {
+  // No real munmap for tegrav4l2 device.

[Pawel Osciak, 2014/02/10 06:36:17]

If so, how is unmapping handled then? What if we want to free the buffers and
reallocate them? You cannot call REQBUFS(0) without unmapping the buffers
first...

[shivdasp, 2014/02/10 13:31:17]

Buffers are unmapped in REQBUFS(0) call and destroyed.
Since there is no real need for mmap and munmap, we did not implement it in the
library.
So our implementation for REQBUF(x) on OUTPUT_PLANE allocates and mmaps the
buffer whereas REQBUF(0) unmaps and destroys them.

On 2014/02/10 06:36:17, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/12 09:15:13]

We should not rely on V4L2VDA to be the only place where the underlying memory
will be destroyed. Even if we REQBUFS(0) on these buffers, the renderer process
may still be keeping ownership of the textures bound to them. Is this taken into
account?

[shivdasp, 2014/02/12 10:11:55]

If not in REQBUFS(0) then what will be the appropriate place to destroy the
buffers ?
V4L2VDA::DestroyOutputBuffers() calls REQBUFS(0) and hence we destroy it there.
How does the renderer then inform the ownership of textures ?



On 2014/02/12 09:15:13, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/13 10:42:54]

Sorry, perhaps I wasn't clear, the term "buffers" is a bit overloaded. I mean
the underlying memory. REQBUFS(0) may be called, but the actual memory that
backed the v4l2_buffers may have to live on if it's still tied to the textures.
This will be a common case actually, because we don't explicitly destroy
textures first unless they are dismissed. The memory should be then freed when
the textures are deleted, not on REQBUFS(0). I'm wondering if the library/driver
take this into account.
Of course, it's still possible for REQUBFS(0) to have to trigger destruction of
underlying memory, in case the textures get unbound and deleted before
REQBUFS(0) is called.
glDeleteTextures(). So the textures and the underlying memory may have to
outlive REQBUFS(0).

[shivdasp, 2014/02/14 03:06:45]

Understood. I believe the dmabuf export mechanism takes care of this in Exynos
since the buffer backed memory is in kernel and hence the deletion is kind of
synchronized.

I see in DestroyOutputbuffers(), before calling DismissPicture(), the
eglDestroyImageKHR() is called thereby the textures are unbound or perhaps the
deletion there is also delayed ?
How is the texture being rendered if the eglImage it is bound to is also
destroyed ?

On 2014/02/13 10:42:54, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/14 07:36:10]

Yes, although it's not "synchronized", but the ownership is managed and
refcounted in the driver and the memory is freed when there is no more users.
How does Tegra manage this?
Destroying the image doesn't destroy the textures, but it does unbind them.
Texture is a separate entity from the eglImage, they share the underlying memory
after binding, but after eglImage is destroyed, the memory is not freed and it
lives on in the texture.

[shivdasp, 2014/02/14 09:18:58]

I checked with the graphics team here. This is handled. Since the memory for
EglImage is refcounted and is backed-up by the graphics library itself, the
texture bound to a destroyed eglImage can still be rendered. The V4L2 REQBUFS(0)
shall de-allocate only the buffer allocated by the "actual decoder" which are
the YUV buffers and since there is no more conversion happening after REQBUFS(0)
this is handled too.

+  return;
+}
+
+bool TegraV4L2Device::SetDevicePollInterrupt(void) {

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

drop "void"

+  if (HANDLE_EINTR(TegraV4L2SetDevicePollInterrupt(device_fd_) == -1)) {

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

bug: HANDLE_EINTR should not be accepting the ==-1 as part of its arg.

+    DLOG(ERROR) << "Error in calling TegraV4L2SetDevicePollInterrupt";
+    return false;
+  }
+  return true;
+}
+
+bool TegraV4L2Device::ClearDevicePollInterrupt(void) {
+  if (HANDLE_EINTR(TegraV4L2ClearDevicePollInterrupt(device_fd_) == -1)) {
+    DLOG(ERROR) << "Error in calling TegraV4L2ClearDevicePollInterrupt";
+    return false;
+  }
+  return true;
+}
+
+bool TegraV4L2Device::Initialize(void) {

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

drop "void"

+  TegraV4L2Open = reinterpret_cast<TegraV4L2OpenFunc>(

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

Please avoid the sort of code duplication below (see vaapi_wrapper.cc for
example of dlsym'ing).

[shivdasp, 2014/02/10 13:31:17]

Yes I will do this. That looks very clean.
On 2014/02/07 09:09:30, Ami Fischman wrote:

+      dlsym(RTLD_DEFAULT, "tegra_v4l2_open"));
+  if (TegraV4L2Open == NULL) {
+    DLOG(ERROR) << "Unable to get Tegra_v4l2_open handle ";
+    return false;
+  }
+
+  TegraV4L2Ioctl = reinterpret_cast<TegraV4L2IoctlFunc>(
+      dlsym(RTLD_DEFAULT, "tegra_v4l2_ioctl"));
+  if (TegraV4L2Ioctl == NULL) {
+    DLOG(ERROR) << "Unable to get tegra_v4l2_ioctl handle ";
+    return false;
+  }
+
+  TegraV4L2Close = reinterpret_cast<TegraV4L2CloseFunc>(
+      dlsym(RTLD_DEFAULT, "tegra_v4l2_close"));
+  if (TegraV4L2Close == NULL) {
+    DLOG(ERROR) << "Unable to get tegra_v4l2_close handle ";
+    return false;
+  }
+
+  TegraV4L2Poll = reinterpret_cast<TegraV4L2PollFunc>(
+      dlsym(RTLD_DEFAULT, "tegra_v4l2_poll"));
+  if (TegraV4L2Poll == NULL) {
+    DLOG(ERROR) << "Unable to get tegra_v4l2_poll handle ";
+    return false;
+  }
+
+  TegraV4L2SetDevicePollInterrupt =
+      reinterpret_cast<TegraV4L2SetDevicePollInterruptFunc>(
+          dlsym(RTLD_DEFAULT, "tegra_v4l2_set_device_poll_interrupt"));
+  if (TegraV4L2SetDevicePollInterrupt == NULL) {
+    DLOG(ERROR) << "Unable to get tegra_v4l2_set_device_poll_interrupt handle";
+    return false;
+  }
+
+  TegraV4L2ClearDevicePollInterrupt =
+      reinterpret_cast<TegraV4L2ClearDevicePollInterruptFunc>(
+          dlsym(RTLD_DEFAULT, "tegra_v4l2_clear_device_poll_interrupt"));
+  if (TegraV4L2ClearDevicePollInterrupt == NULL) {
+    DLOG(ERROR)
+        << "Unable to get tegra_v4l2_clear_device_poll_interrupt handle ";
+    return false;
+  }
+
+  device_fd_ =
+      HANDLE_EINTR(TegraV4L2Open(kDevice, O_RDWR | O_NONBLOCK | O_CLOEXEC));
+  if (device_fd_ == -1) {
+    DLOG(ERROR) << "Unable to open tegra_v4l2_open ";
+    return false;
+  }
+  return true;
+}
+
+EGLImageKHR TegraV4L2Device::CreateEGLImage(EGLDisplay egl_display,
+                                            EGLint attrib[],

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

EGLint[] /* attrib */

+                                            unsigned int texture_id,
+                                            unsigned int buffer_index) {

[Pawel Osciak, 2014/02/10 06:36:17]

This method should take a v4l2_buffer instead. 
Depending on format and other circumstances format, memory type, etc. change. We
shouldn't hardcode this in the device class.

[shivdasp, 2014/02/10 13:31:17]

Since ExynosV4L2Device does not need the v4l2_buffer like TegraV4L2Device, I
thought it would add less noise to the V4L2VDA code.
Also the fields within the v4l2_buffer (the eglimage handle) is created within
this method so can't fully initialize the structure here.
On 2014/02/10 06:36:17, Pawel Osciak wrote:

+  // Ignore the attributes sent to us since Tegra does not need those.
+  EGLint attr = EGL_NONE;
+  EGLImageKHR egl_image = eglCreateImageKHR(egl_display,
+                                            egl_context_,
+                                            EGL_GL_TEXTURE_2D_KHR,
+                                            (EGLClientBuffer)(texture_id),

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

static_cast

+                                            &attr);
+  if (egl_image == EGL_NO_IMAGE_KHR) {
+    DLOG(ERROR) << "CreateEGLImage(): could not create EGLImageKHR";
+    return egl_image;
+  }
+
+  struct v4l2_plane planes[2];
+  struct v4l2_buffer capture_buffer;
+
+  memset(&capture_buffer, 0, sizeof(capture_buffer));
+  memset(planes, 0, sizeof(planes));

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

swap w/ previous line to match declaration order

+  capture_buffer.index = buffer_index;
+  capture_buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  capture_buffer.memory = V4L2_MEMORY_MMAP;
+  capture_buffer.m.planes = planes;
+  capture_buffer.length = 2;

[Pawel Osciak, 2014/02/10 06:36:17]

arraysize(planes)

+  // We send the EGLImage handle in mem_offset for the library to perform
+  // conversion internally
+
+  planes[0].m.mem_offset = reinterpret_cast<unsigned int>(egl_image);

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

how wide is mem_offset?  I'm worried about this cast on a 64-bit platform.
If mem_offset is intptr_t-sized, please use that in the cast.  

[Pawel Osciak, 2014/02/10 06:36:17]

mem_offset is u32 always, an unsigned int shouldn't be assigned to it. Also,
there are two planes, but passing only one offset is a bit inconsistent.
Although, why have two planes, if only one is used?

[shivdasp, 2014/02/10 13:31:17]

We are really passing in the EglImage handle here to the library. The library
associates this with the corresponding v4l2_buffer on the CAPTURE plane and use
the underlying conversion APIs to transform the decoder's yuv output into the
egl image.
We have two planes on CAPTURE_PLANE to comply with V4L2VDA code where the number
of planes are checked with 2 (line #1660 of V4L2VDA).

On 2014/02/10 06:36:17, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/12 09:15:13]

EGLImageKHR is typedef void*, which can be 64 bit. It cannot be passed in an u32
variable.

The whole idea behind offsets is that they are usually not really offsets, but
sort of platform-independent 32bit IDs. They are acquired from the V4L2 driver
(or library) via QUERYBUFS, and can be passed back to other calls to uniquely
identify the buffers (e.g. to mmap).

The client is not supposed to generate them by itself and pass them to
QUERYBUFS.
You mean
https://code.google.com/p/chromium/codesearch#chromium/src/content/common/gpu...
? 

This is an overassumption from the time where there was only one format
supported.
The number of planes to be used should be taken from the v4l2_format struct,
returned from G_FMT. This assumption should be fixed.

From what I'm seeing here, your HW doesn't really use V4L2_PIX_FMT_NV12M? Which
fourcc format does it use? Are the planes separate memory buffers?

[shivdasp, 2014/02/12 10:11:55]

The output is YUV420 planar. I think rather than using the QUERYBUF to pass the
EglImage handles and stuffing the required information I would rather introduce
a custom API (UseEglImage ?).
I hope that is fine.

On 2014/02/12 09:15:13, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/13 10:42:54]

Are all planes non-interleaved and contiguous in memory? If so, then you need to
use either V4L2_PIX_FMT_YVU420 ('YV12') or V4L2_PIX_FMT_YUV420 ('YU12'), please
see http://linuxtv.org/downloads/v4l-dvb-apis/re23.html.

Please don't use V4L2_PIX_FMT_NV12M if this is not what codec produces.
Yes, it's preferable over using QUERYBUF for this. But let's agree on the shape
of it. What would UseEglImage do?
Could we instead pass the offsets to eglCreateImageKHR?
Will we be able to also retain texture binding in V4L2VDA then?

[shivdasp, 2014/02/14 03:06:45]

Okay I will change the pixel format. However there are some DHECK_EQ() code in
V4L2VDA to check against V4L2_PIX_FMT_NV12M.
They also exist for num_planes. I will have to introduce private member
functions for ExynosV4L2Device and TegraV4L2Device to check against them rather
than hardcoded values in V4L2VDA. Will that be fine ?
I was thinking of int UseEglImage(int buffer_index, EGLImageKHR egl_image);
We basically need to send the EglImage created for a particular buffer_index so
the library can convert YUV into its respective EglImage.
We cannot send offsets to eglCreateImageKHR unless we have extension. However
the buffer_index internally is the mapping for identifying the eglImage so in a
way that will work like an offset.

[Pawel Osciak, 2014/02/14 07:36:10]

As I said, those checks and should be fixed to use the actual format given by
the device.
There is no need to have private member methods for devices. V4L2 API gives you
methods to query and get formats as well as information how many planes each
format uses. Please see documentation for v4l2_pix_format{,_mplane}
in http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-g-fmt.html.
I really don't see why it should be an issue to create such an extension with
very minimal effort.
It should be a trivial wrapper around eglCreateImageKHR. Your library has to
call some function in the driver anyway to do this, so why not extract that code
and move it to a special case in eglCreateImageKHR instead? The code is already
written I assume, since you use it, it just needs to be moved to a different
location (i.e. eglCreateImageKHR implementation).

[shivdasp, 2014/02/14 09:18:58]

Okay will use the V4L2 API.
The graphics stack is owned by a separate team so I don't really understand the
implementation issues if any.
I will check if there is such plan in the meanwhile let me address all these
review comments and send out second patchset.

+  if (HANDLE_EINTR(Ioctl(VIDIOC_QUERYBUF, &capture_buffer)) != 0) {
+    DLOG(ERROR) << "Some error in querybuf";
+    return EGL_NO_IMAGE_KHR;

[Ami GONE FROM CHROMIUM, 2014/02/07 09:09:30]

leak?  (no eglDestroyImageKHR needed?)

[shivdasp, 2014/02/10 13:31:17]

Yes will fix this.
On 2014/02/07 09:09:30, Ami Fischman wrote:

+  }
+  return egl_image;
+}

[Pawel Osciak, 2014/02/10 06:36:17]

After reading through it, this method feels unnecessary.

I'm assuming querybufs implementation in the library calls a method in the GPU
driver anyway?

This is basically redefining querybufs to do something completely different than
it normally does, turning it into a custom call. The offsets should be coming
from the callee of QUERYBUFS, not the other way around, and there should be no
custom side effects.
A non-V4L2, library-specific custom call would be better than this.

But why not implement eglCreateImageKHR that accepts dmabufs (or even offsets)
that come from the v4l2 library to create EGL images, just like we do on Mali on
Exynos?

Would it be possible to have an extension for eglCreateImage like Exynos does
instead please? It doesn't seem to be much of a difference, instead of calling
querybufs with custom arguments and having the library call something in the
driver, call eglCreateImage instead with custom arguments and have it do
everything?

[shivdasp, 2014/02/10 13:31:17]

Since we started with implementing this as a V4L2-Like library we have tried to
follow V4L2 syntax to provide the input & output buffers.
QUERYBUF can be made into a custom call since it is doing very custom thing
here.
If introducing another API is acceptable I can do that.

We do not yet have eglCreateImageKHR that accepts dmabufs. I can check with the
our Graphics team but I don't there is any such plan to implement such
extension.

On 2014/02/10 06:36:17, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/12 09:15:13]

Please understand that:
1. We are asking for a V4L2-like interface that conforms to the V4L2 API. A call
documented to work in the same way regardless of buffer type passed should not
do otherwise, if it can be prevented. If it's expected to return values, it
shouldn't be accepting them instead. And so on.
Of course, this is an adapter class, so the actual inner workings may be
different and it's not always possible to do exactly the same thing, but from
the point of view of the client the effects should be as close to what each call
is documented to do, as possible.

Otherwise this whole exercise of using V4L2 API is doing us more bad than good.

Please understand that the V4L2VDA and V4L2VEA classes will live on and will
work with multiple platforms. There will be many changes to them. People working
on them will expect behavior as documented in V4L2 API. Otherwise things will
break (and not only for other platforms, but Tegra too) and it will be very
difficult to reason why.

So it's very important for Tegra V4L2Device to behave like V4L2 API specifies
and not be tailored to how things are laid out in V4L2VDA currently.

2. This V4L2Device class should work with V4L2VEA class as well. I don't think
we can make it work if this hack on QUERYBUFS is here.
That's why I gave the option of using offsets. If you prefer not to use dmabufs,
could we please:

- provide offsets via querybufs from the driver/library
- pass those offsets to a new eglCreateImage extension and move it back to
V4L2VDA
- keep using texture binding API?

This should eliminate the need for this method as well.

[shivdasp, 2014/02/12 10:11:55]

There is no extension to create EglImages from dmabufs or the offsets at the
moment unfortunately.
I agree using the QUERYBUF for sending the EglImage can be misleading and I will
change it. V4L2VEA should not affected since we use the QUERYBUF for providing
the actual offsets. This hack was only for sending the EglImages in case of
CAPTURE PLANE of decoder.
As I said earlier will adding a custom API (for now) to send the EglImages be
okay ?


On 2014/02/12 09:15:13, Pawel Osciak wrote:

[Pawel Osciak, 2014/02/13 10:42:54]

Could you explain why is it not affected? VEA calls QUERYBUF on CAPTURE buffers.

[shivdasp, 2014/02/14 03:06:45]

The fd returned by TegraV4L2Open() knows whether it was for a decoder instance
or encoder instance.
Hence QUERYBUF on CAPTURE_PLANE for an encoder will behave as per the V4L2
specification. An alternate hacky behavior was needed for decoder instance to
send EglImages which we are now sending in custom call.

On 2014/02/13 10:42:54, Pawel Osciak wrote:

+
+unsigned int TegraV4L2Device::GetTextureTarget() { return GL_TEXTURE_2D; }
+
+}  //  namespace content