Add CDM video decoder.

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..6ea29411fa3541c00107beeb7a2908374914cd49 100644
--- a/webkit/media/crypto/ppapi/content_decryption_module.h
+++ b/webkit/media/crypto/ppapi/content_decryption_module.h
@@ -8,11 +8,13 @@
 #if defined(_MSC_VER)
 typedef unsigned char uint8_t;
 typedef unsigned int uint32_t;
+typedef int int32_t;
 typedef __int64 int64_t;
 #else
 #include <stdint.h>
 #endif
 
+#include "base/time.h"
 #include "webkit/media/crypto/ppapi/cdm_export.h"
 
 namespace cdm {
@@ -129,6 +131,100 @@ struct OutputBuffer {
   int64_t timestamp;  // Presentation timestamp in microseconds.
 };
 
+struct VideoFrame {
+  // Surface formats roughly based on FOURCC labels, see:
+  // http://www.fourcc.org/rgb.php
+  // http://www.fourcc.org/yuv.php
+  enum Format {

[ddorwin, 2012/08/29 17:33:49]

Maybe ColorFormat or something like that. Unless "Format" is commonly understood
in this context.

[Tom Finegan, 2012/08/30 17:09:23]

From src/media, but went with ColorFormat because I prefer the more descriptive
type name.

+    INVALID = 0,  // Invalid format value.  Used for error reporting.

[ddorwin, 2012/08/29 17:33:49]

Check the naming in style guide. Might need more context in the name.

[Tom Finegan, 2012/08/30 17:09:23]

From src/media. Fixed this, and discarded everything but I420 and YV12. 

+    RGB32,  // 32bpp RGB packed with extra byte 8:8:8.
+    YV12,  // 12bpp YVU planar 1x1 Y, 2x2 VU samples.

[ddorwin, 2012/08/29 17:33:49]

Should probably align comments in this case.

[Tom Finegan, 2012/08/30 17:09:23]

Done.

+    YV16,  // 16bpp YVU planar 1x1 Y, 2x1 VU samples.
+    EMPTY,  // An empty frame.

[ddorwin, 2012/08/29 17:33:49]

Why is EMPTY in the middle of YVU items? Should it be after INVALID instead?

[Tom Finegan, 2012/08/30 17:09:23]

From src/media.

+    I420,  // 12bpp YVU planar 1x1 Y, 2x2 UV samples.
+  };
+
+  struct Size {
+    Size() : width(0), height(0) {}
+    Size(int32_t width, int32_t height) : width(width), height(height) {}
+
+    int32_t width;
+    int32_t height;
+  };
+
+  const static int32_t kMaxPlanes = 3;
+
+  VideoFrame() : format(INVALID) {
+    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;

[ddorwin, 2012/08/29 17:33:49]

frame_size. data doesn't seem right.

[Tom Finegan, 2012/08/30 17:09:23]

From src/media, but I prefer frame_size. Done.

+
+  // 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];
+
+  base::TimeDelta timestamp;  // Presentation timestamp in microseconds.
+};
+
+struct VideoDecoderConfig {
+  enum VideoCodec {
+    kUnknownVideoCodec = 0,

[ddorwin, 2012/08/29 17:33:49]

This name is inconsistent with the rest.

[Tom Finegan, 2012/08/30 17:09:23]

From src/media. Dropped everything but unknown, h264, and vp8. Fixed
inconsistent naming, and set kCodecVp8 to 6 so that the value matches the one
from media.

+    kCodecH264,

[ddorwin, 2012/08/29 17:33:49]

kName vs. NAME for Format. Pick one - see style guide.

[Tom Finegan, 2012/08/30 17:09:23]

The naming inconsistency is due to src/media ancestry. I don't think fixing it
hurts anything, so: Done.

+    kCodecVC1,

[ddorwin, 2012/08/29 17:33:49]

We're not going to support these 4, so remove them.

[Tom Finegan, 2012/08/30 17:09:23]

Done.

+    kCodecMPEG2,
+    kCodecMPEG4,
+    kCodecTheora,
+    kCodecVP8
+  };
+
+  enum VideoCodecProfile {
+    VIDEO_CODEC_PROFILE_UNKNOWN = -1,
+    H264PROFILE_MIN = 0,

[ddorwin, 2012/08/29 17:33:49]

I wonder if Chrome supports all these.

[Tom Finegan, 2012/08/30 17:09:23]

From src/media, and probably something we should look into as we probably need
only a few of these.

+    H264PROFILE_BASELINE = H264PROFILE_MIN,
+    H264PROFILE_MAIN = 1,
+    H264PROFILE_EXTENDED = 2,
+    H264PROFILE_HIGH = 3,
+    H264PROFILE_HIGH10PROFILE = 4,
+    H264PROFILE_HIGH422PROFILE = 5,
+    H264PROFILE_HIGH444PREDICTIVEPROFILE = 6,
+    H264PROFILE_SCALABLEBASELINE = 7,
+    H264PROFILE_SCALABLEHIGH = 8,
+    H264PROFILE_STEREOHIGH = 9,
+    H264PROFILE_MULTIVIEWHIGH = 10,
+    H264PROFILE_MAX = H264PROFILE_MULTIVIEWHIGH,
+    VP8PROFILE_MIN = 11,
+    VP8PROFILE_MAIN = VP8PROFILE_MIN,
+    VP8PROFILE_MAX = VP8PROFILE_MAIN,
+    VIDEO_CODEC_PROFILE_MAX = VP8PROFILE_MAX
+  };
+
+  VideoCodec codec;
+  VideoCodecProfile profile;
+  VideoFrame::Format format;

[ddorwin, 2012/08/29 17:33:49]

Why do both the frame and config have a format and size?

[Tom Finegan, 2012/08/30 17:09:23]

From src/media.

I think this is because we need a format and a size to init the FFmpeg decoder,
and we need the same at decode time (but we won't be hanging onto the config).

[ddorwin, 2012/09/02 21:39:07]

It seems this would only be used for error checking. Otherwise, why doesn't the
CDM just hang onto the values? (A question for scherkus.)

+  VideoFrame::Size coded_size;

[ddorwin, 2012/08/29 17:33:49]

coded?
encoded? compressed?

[Tom Finegan, 2012/08/30 17:09:23]

Done, s/coded_size/frame_size/.

+  uint8_t* extra_data;

[ddorwin, 2012/08/29 17:33:49]

What is this?

[Tom Finegan, 2012/08/30 17:09:23]

From src/media.

Comment from media/base/video_decoder_config.h:
// Optional byte data required to initialize video decoders, such as H.264
// AAVC data.

[ddorwin, 2012/09/02 21:39:07]

Will we definitely need this? If so, we should probably have a similar comment.
Alternatively, maybe we can add it later.

+  int32_t extra_data_size;
+
+  VideoDecoderConfig()
+      : codec(kUnknownVideoCodec),
+        profile(VIDEO_CODEC_PROFILE_UNKNOWN),
+        format(VideoFrame::INVALID),
+        coded_size(0, 0),
+        extra_data(NULL),
+        extra_data_size(0) {}
+};
+
 class ContentDecryptionModule {
  public:
   // Generates a |key_request| given the |init_data|.
@@ -178,6 +274,32 @@ class ContentDecryptionModule {
   virtual Status Decrypt(const InputBuffer& encrypted_buffer,
                          OutputBuffer* decrypted_buffer) = 0;
 
+  // Initializes the CDM video decoder with |video_decoder_config|. This

[ddorwin, 2012/08/29 17:33:49]

To keep Decrypt* together, I would move this above Decrypt().

[Tom Finegan, 2012/08/30 17:09:23]

Done.

+  // 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 kErrorUnknown otherwise.
+  virtual Status InitializeVideoDecoder(
+      const VideoDecoderConfig& 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.

[ddorwin, 2012/08/29 17:33:49]

Do we need a Flush() if no longer care about the frames? Maybe not since the
plugin is destroyed when loading.

[Tom Finegan, 2012/08/30 17:09:23]

We might need it for seeking, added.

+  // 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.
+  // 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 DecryptAndDecode(const InputBuffer& encrypted_buffer,
+                                  VideoFrame* video_frame) = 0;
+
   virtual ~ContentDecryptionModule() {}
 };