Extend media glue code to support the VideoToolbox cast video encoder.

media/base/mac/coremedia_glue.h

Index: media/base/mac/coremedia_glue.h
diff --git a/media/base/mac/coremedia_glue.h b/media/base/mac/coremedia_glue.h
index 2cafeeac4040b00e53d55814ce5adcd155a9400b..b64a27f3cf0a86cdfca9216ed816593ee4999db2 100644
--- a/media/base/mac/coremedia_glue.h
+++ b/media/base/mac/coremedia_glue.h
@@ -28,9 +28,20 @@ class MEDIA_EXPORT CoreMediaGlue {
     CMTimeEpoch epoch;
   } CMTime;
 
+  // Originally from CMBlockBuffer.h
+  typedef uint32_t CMBlockBufferFlags;
+  typedef struct OpaqueCMBlockBuffer* CMBlockBufferRef;
+  typedef struct {
+    uint32_t version;
+    void* (*AllocateBlock)(void*, size_t);
+    void (*FreeBlock)(void*, void*, size_t);
+    void* refCon;
+  } CMBlockBufferCustomBlockSource;
+
   // Originally from CMFormatDescription.h.
   typedef const struct opaqueCMFormatDescription* CMFormatDescriptionRef;
   typedef CMFormatDescriptionRef CMVideoFormatDescriptionRef;
+  typedef FourCharCode CMVideoCodecType;
   typedef struct {
     int32_t width;
     int32_t height;
@@ -40,6 +51,12 @@ class MEDIA_EXPORT CoreMediaGlue {
   };
   enum {
     kCMVideoCodecType_JPEG_OpenDML = 'dmb1',
+    kCMVideoCodecType_H264 = 'avc1',
+  };
+
+  // Originally from CMFormatDescriptionBridge.h
+  enum {
+    kCMFormatDescriptionBridgeError_InvalidParameter = -12712,
   };
 
   // Originally from CMSampleBuffer.h.
@@ -48,15 +65,50 @@ class MEDIA_EXPORT CoreMediaGlue {
   // Originally from CMTime.h.
   static CMTime CMTimeMake(int64_t value, int32_t timescale);
 
+  // Originally from CMBlockBuffer.h
+  static OSStatus CMBlockBufferCreateContiguous(
+      CFAllocatorRef structureAllocator,
+      CMBlockBufferRef sourceBuffer,
+      CFAllocatorRef blockAllocator,
+      const CMBlockBufferCustomBlockSource* customBlockSource,
+      size_t offsetToData,
+      size_t dataLength,
+      CMBlockBufferFlags flags,
+      CMBlockBufferRef* newBBufOut);
+  static size_t CMBlockBufferGetDataLength(CMBlockBufferRef theBuffer);
+  static OSStatus CMBlockBufferGetDataPointer(CMBlockBufferRef theBuffer,
+                                              size_t offset,
+                                              size_t* lengthAtOffset,
+                                              size_t* totalLength,
+                                              char** dataPointer);
+  static Boolean CMBlockBufferIsRangeContiguous(CMBlockBufferRef theBuffer,
+                                                size_t offset,
+                                                size_t length);
+
   // Originally from CMSampleBuffer.h.
+  static CMBlockBufferRef CMSampleBufferGetDataBuffer(CMSampleBufferRef sbuf);
+  static CMFormatDescriptionRef CMSampleBufferGetFormatDescription(
+      CMSampleBufferRef sbuf);
   static CVImageBufferRef CMSampleBufferGetImageBuffer(
       CMSampleBufferRef buffer);
+  static CFArrayRef CMSampleBufferGetSampleAttachmentsArray(
+      CMSampleBufferRef sbuf,
+      Boolean createIfNecessary);
+  static CFStringRef kCMSampleAttachmentKey_NotSync();
 
   // Originally from CMFormatDescription.h.
   static FourCharCode CMFormatDescriptionGetMediaSubType(
       CMFormatDescriptionRef desc);
   static CMVideoDimensions CMVideoFormatDescriptionGetDimensions(
       CMVideoFormatDescriptionRef videoDesc);
+  static OSStatus CMVideoFormatDescriptionGetH264ParameterSetAtIndex(
+      CMFormatDescriptionRef videoDesc,
+      size_t parameterSetIndex,
+      const uint8_t** parameterSetPointerOut,
+      size_t* parameterSetSizeOut,
+      size_t* parameterSetCountOut,
+      int* NALUnitHeaderLengthOut)
+      /*__OSX_AVAILABLE_STARTING(__MAC_10_9,__IPHONE_7_0)*/;

[Robert Sesek, 2014/09/12 16:16:16]

None of the other functions carry these comments, so I'd remove.

[jfroy, 2014/09/12 17:11:46]

Unlike every other function in the CoreMedia glue, this function is only
available on 10.9 and 7.0. If you try to call it on an unsupported OS, you will
crash on a null dereference. There has to be some indication of this. Any
suggestion?

Also as a note, no one seems to be using the CoreMedia glue directly, or
primarily. The AVF glue and the H.264 VT encoder do, but they check for AVF or
VT availability first, which both guarantee that CM is available. The CM glue
itself provides no mechanism to check for availability. On first use the lazy
instance is created and if CM is not there you CHECK assert.

 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(CoreMediaGlue);