Add video decoding support in the CDM interface.

webkit/media/crypto/ppapi/content_decryption_module.h

Index: webkit/media/crypto/ppapi/content_decryption_module.h
diff --git a/webkit/media/crypto/ppapi/content_decryption_module.h b/webkit/media/crypto/ppapi/content_decryption_module.h
index cb21258a6fb24feb19ab45813e34f3c15fb1082d..273cd57492ebd7b6b1d33956f5714c20022bf728 100644
--- a/webkit/media/crypto/ppapi/content_decryption_module.h
+++ b/webkit/media/crypto/ppapi/content_decryption_module.h
@@ -30,7 +30,8 @@ namespace cdm {
 enum Status {
   kSuccess = 0,
   kErrorUnknown,
-  kErrorNoKey
+  kErrorNoKey,
+  kErrorDecryptOnly
 };
 
 // TODO(xhwang): Use int32_t instead of uint32_t for sizes here and below and
@@ -129,6 +130,75 @@ struct OutputBuffer {
   int64_t timestamp;  // Presentation timestamp in microseconds.
 };
 
+struct VideoFrame {
+  // Surface formats based on FOURCC labels, see:
+  // http://www.fourcc.org/yuv.php
+  enum Format {
+    kInvalidFormat = 0,  // Invalid format value.  Used for error reporting.
+    kI420  // 12bpp YVU planar 1x1 Y, 2x2 UV samples.

[xhwang, 2012/09/01 13:14:37]

Tom: in vp8, we use I420, not YV12, correct?

+  };
+
+  struct Size {
+    Size() : width(0), height(0) {}
+    Size(int32_t width, int32_t height) : width(width), height(height) {}
+
+    int32_t width;
+    int32_t height;
+  };
+
+  static const int32_t kMaxPlanes = 3;
+
+  VideoFrame()
+      : format(kInvalidFormat),
+        timestamp(0) {
+    for (int i = 0; i < kMaxPlanes; ++i) {
+      strides[i] = 0;
+      data[i] = NULL;
+    }
+  }
+
+  Format format;
+
+  // Width and height of the video frame.
+  Size data_size;
+
+  // Array of strides for each plane, typically greater or equal to the width
+  // of the surface divided by the horizontal sampling period.  Note that
+  // strides can be negative.
+  int32_t strides[kMaxPlanes];
+
+  // Array of data pointers to each plane.
+  uint8_t* data[kMaxPlanes];
+
+  int64_t timestamp;  // Presentation timestamp in microseconds.
+};
+
+struct VideoDeocderConfig {

[scherkus (not reviewing), 2012/09/02 09:13:24]

typo

[xhwang, 2012/09/02 10:40:33]

Done.

+  enum VideoCodec {
+    kUnknownVideoCodec = 0,
+    kCodecVP8
+  };
+
+  enum VideoCodecProfile {
+    kUnknownVideoCodecProfile = 0,
+    kVp8ProfileMain
+  };
+
+  VideoDeocderConfig()
+      : codec(kUnknownVideoCodec),
+        profile(kUnknownVideoCodecProfile),
+        format(VideoFrame::kInvalidFormat),
+        extra_data(NULL),
+        extra_data_size() {}
+
+  VideoCodec codec;
+  VideoCodecProfile profile;
+  VideoFrame::Format format;
+  VideoFrame::Size coded_size;
+  uint8_t* extra_data;
+  int32_t extra_data_size;
+};
+
 class ContentDecryptionModule {
  public:
   // Generates a |key_request| given the |init_data|.
@@ -178,6 +248,47 @@ class ContentDecryptionModule {
   virtual Status Decrypt(const InputBuffer& encrypted_buffer,
                          OutputBuffer* decrypted_buffer) = 0;
 
+  // Initializes the CDM video decoder with |video_decoder_config|. This
+  // function must be called before DecryptAndDecode() is called.
+  // Returns kSuccess if the |video_decoder_config| is supported and the CDM
+  // video decoder is successfully initialized.
+  // Returns kErrorDecryptOnly if the |video_decoder_config| is not supported
+  // but the CDM can still be used to Decrypt() the video stream.
+  // Returns kErrorUnknown if |video_decoder_config| is not supported and the
+  // CDM can not be used (or is not allowed) to Decrypt() the video stream.
+  virtual Status InitializeVideoDecoder(
+      const VideoDeocderConfig& video_decoder_config) = 0;
+
+  // Decrypts the |encrypted_buffer| and decodes the decrypted buffer into a
+  // |video_frame|. Upon end-of-stream, the caller should call this function
+  // repeatedly with empty |encrypted_buffer| (where |data| is NULL) until
+  // only empty (|format| being EMPTY) |video_frame| can be produced.

[scherkus (not reviewing), 2012/09/02 09:13:24]

what's EMPTY? I only see kInvalidFormat

[xhwang, 2012/09/02 10:40:33]

Done.

+  // Returns kSuccess if decryption and decoding both succeeded, in which case
+  // the callee should have filled the |video_frame| and passed the ownership of
+  // |data| in |video_frame| to the caller.

[scherkus (not reviewing), 2012/09/02 09:13:24]

what about decoders with delay? the first few calls may return empty frames

what's the error code when flushing end of the stream? is it kSuccess +
kInvalidFormat?

[xhwang, 2012/09/02 10:40:33]

Done.

+  // Returns kErrorNoKey if the CDM did not have the necessary decryption key
+  // to decrypt.
+  // Returns kErrorUnknown if any other (decryption or decoding) error happened.
+  // In these two cases, |video_frame| should not be used by the caller.
+  //
+  // TODO(xhwang): It's not safe to pass the ownership of the dynamically
+  // allocated memory over library boundaries. Fix it after related PPAPI change
+  // and sample CDM are landed.
+  virtual Status DecryptAndDecodeVideo(const InputBuffer& encrypted_buffer,
+                                       VideoFrame* video_frame) = 0;
+
+  // Resets the CDM video decoder to an initialized clean state.
+  // Returns kSuccess if the video decoder is successfully reset.
+  // Returns kErrorUnknown otherwise.
+  virtual Status ResetVideoDecoder() = 0;
+
+  // Stops the CDM video decoder and set it to an uninitialized state. Note
+  // that a VideoDecoder should/could not be re-initialized after it has been

[scherkus (not reviewing), 2012/09/02 09:13:24]

should/could not -> cannot

[xhwang, 2012/09/02 10:40:33]

Done.

+  // stopped.
+  // Returns kSuccess if the video decoder is successfully stopped.
+  // Returns kErrorUnknown otherwise.
+  virtual Status StopVideoDecoder() = 0;

[scherkus (not reviewing), 2012/09/02 09:13:24]

what does Stop() + kErrorUnknown mean?

[xhwang, 2012/09/02 10:40:33]

Right, in media code the callback is a closure. Update this and
ResetVideoDecoder() to return void.

+
   virtual ~ContentDecryptionModule() {}
 };