Introduce a client minimum picture pool size

ppapi/cpp/video_decoder.h

 // Copyright (c) 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.
 
 #ifndef PPAPI_CPP_VIDEO_DECODER_H_
 #define PPAPI_CPP_VIDEO_DECODER_H_
 
 #include "ppapi/c/pp_codecs.h"
 #include "ppapi/c/pp_size.h"
 #include "ppapi/cpp/completion_callback.h"
@@ skipping 47 matching lines @@
 
   /// Initializes a video decoder resource. This should be called after Create()
   /// and before any other functions.
   ///
   /// @param[in] graphics3d_context A <code>PPB_Graphics3D</code> resource to
   /// use during decoding.
   /// @param[in] profile A <code>PP_VideoProfile</code> specifying the video
   /// codec profile.
   /// @param[in] acceleration A <code>PP_HardwareAcceleration</code> specifying
   /// whether to use a hardware accelerated or a software implementation.
+  /// @param[in] min_picture_count A count of pictures the plugin would like to
+  /// have in flight. This is effectively the number of times the plugin can
+  /// call GetPicture() and get a decoded frame without calling
+  /// RecyclePicture(). The decoder has its own internal minimum count, and will
+  /// take the larger of its internal and this value. A client that doesn't care
+  /// can therefore just pass in zero for this argument.
   /// @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
   /// completion.
   ///
   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
   /// Returns PP_ERROR_NOTSUPPORTED if video decoding is not available, or the
   /// requested profile is not supported. In this case, the client may call
   /// Initialize() again with different parameters to find a good configuration.
   int32_t Initialize(const Graphics3D& graphics3d_context,
                      PP_VideoProfile profile,
                      PP_HardwareAcceleration acceleration,
+                     uint32_t min_picture_count,
                      const CompletionCallback& callback);
 
   /// Decodes a bitstream buffer. Copies |size| bytes of data from the plugin's
   /// |buffer|. The plugin should wait until the decoder signals completion by
   /// returning PP_OK or by running |callback| before calling Decode() again.
   ///
   /// In general, each bitstream buffer should contain a demuxed bitstream frame
   /// for the selected video codec. For example, H264 decoders expect to receive
   /// one AnnexB NAL unit, including the 4 byte start code prefix, while VP8
   /// decoders expect to receive a bitstream frame without the IVF frame header.
@@ skipping 79 matching lines @@
   /// completion.
   ///
   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
     /// Returns PP_ERROR_FAILED if the decoder isn't initialized.
 int32_t Reset(const CompletionCallback& callback);
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_VIDEO_DECODER_H_