V4L2VideoDecodeAccelerator: implement flush by VIDIOC_DECODER_CMD.

media/gpu/v4l2_device.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file defines the V4L2Device interface which is used by the
 // V4L2DecodeAccelerator class to delegate/pass the device specific
 // handling of any of the functionalities.
 
 #ifndef MEDIA_GPU_V4L2_DEVICE_H_
 #define MEDIA_GPU_V4L2_DEVICE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <linux/videodev2.h>
 
 #include "base/files/scoped_file.h"
 #include "base/memory/ref_counted.h"
 #include "media/base/video_decoder_config.h"
 #include "media/base/video_frame.h"
 #include "media/gpu/media_gpu_export.h"
 #include "media/video/video_decode_accelerator.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gl/gl_bindings.h"
 
 // TODO(posciak): remove this once V4L2 headers are updated.
-#define V4L2_PIX_FMT_VP9 v4l2_fourcc('V', 'P', '9', '0')
 #define V4L2_PIX_FMT_H264_SLICE v4l2_fourcc('S', '2', '6', '4')
-#define V4L2_PIX_FMT_VP8_FRAME v4l2_fourcc('V', 'P', '8', 'F')

[Pawel Osciak, 2016/10/19 09:23:04]

Why remove VP8F, but not S264? I think they should've both gone in at similar
time?

[wuchengli, 2016/10/20 10:14:06]

You are right. I checked again and S264 is in
third_party/chromiumos-overlay/sys-kernel/linux-headers/files/0001-CHROMIUM-media-headers-Import-V4L2-headers-from-Chro.patch
Third party code! Follow proper procedures.

 #define V4L2_PIX_FMT_MT21 v4l2_fourcc('M', 'T', '2', '1')
+#ifndef V4L2_BUF_FLAG_LAST
+#define V4L2_BUF_FLAG_LAST 0x00100000
+#endif
 
 namespace media {
 
 class MEDIA_GPU_EXPORT V4L2Device
     : public base::RefCountedThreadSafe<V4L2Device> {
  public:
   // Utility format conversion functions
   static VideoPixelFormat V4L2PixFmtToVideoPixelFormat(uint32_t format);
   static uint32_t VideoPixelFormatToV4L2PixFmt(VideoPixelFormat format);
   static uint32_t VideoCodecProfileToV4L2PixFmt(VideoCodecProfile profile,
@@ skipping 109 matching lines @@
   friend class base::RefCountedThreadSafe<V4L2Device>;
   explicit V4L2Device(Type type);
   virtual ~V4L2Device();
 
   const Type type_;
 };
 
 }  //  namespace media
 
 #endif  // MEDIA_GPU_V4L2_DEVICE_H_