Mac Video Capture: Sending the timestamps provided by the driver to the capture pipeline

media/base/mac/coremedia_glue.mm

 // Copyright 2013 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.
 
 #include "media/base/mac/coremedia_glue.h"
 
 #include <dlfcn.h>
 #import <Foundation/Foundation.h>
 
 #include "base/lazy_instance.h"
@@ skipping 33 matching lines @@
   typedef CoreMediaGlue::CMBlockBufferRef (*CMSampleBufferGetDataBufferMethod)(
       CoreMediaGlue::CMSampleBufferRef);
   typedef CoreMediaGlue::CMFormatDescriptionRef (
       *CMSampleBufferGetFormatDescriptionMethod)(
       CoreMediaGlue::CMSampleBufferRef);
   typedef CVImageBufferRef (*CMSampleBufferGetImageBufferMethod)(
       CoreMediaGlue::CMSampleBufferRef);
   typedef CFArrayRef (*CMSampleBufferGetSampleAttachmentsArrayMethod)(
       CoreMediaGlue::CMSampleBufferRef,
       Boolean);
+  typedef CoreMediaGlue::CMTime (*CMSampleBufferGetPresentationTimeStampMethod)(
+      CoreMediaGlue::CMSampleBufferRef);
 
   typedef FourCharCode (*CMFormatDescriptionGetMediaSubTypeMethod)(
       CoreMediaGlue::CMFormatDescriptionRef desc);
   typedef CoreMediaGlue::CMVideoDimensions
       (*CMVideoFormatDescriptionGetDimensionsMethod)(
           CoreMediaGlue::CMVideoFormatDescriptionRef videoDesc);
   typedef OSStatus (*CMVideoFormatDescriptionGetH264ParameterSetAtIndexMethod)(
       CoreMediaGlue::CMFormatDescriptionRef,
       size_t,
       const uint8_t**,
@@ skipping 41 matching lines @@
             dlsym(library_handle, "CMSampleBufferGetFormatDescription"));
     CHECK(cm_sample_buffer_get_format_description_method_) << dlerror();
     cm_sample_buffer_get_image_buffer_method_ =
         reinterpret_cast<CMSampleBufferGetImageBufferMethod>(
             dlsym(library_handle, "CMSampleBufferGetImageBuffer"));
     CHECK(cm_sample_buffer_get_image_buffer_method_) << dlerror();
     cm_sample_buffer_get_sample_attachments_array_method_ =
         reinterpret_cast<CMSampleBufferGetSampleAttachmentsArrayMethod>(
             dlsym(library_handle, "CMSampleBufferGetSampleAttachmentsArray"));
     CHECK(cm_sample_buffer_get_sample_attachments_array_method_) << dlerror();
+    cm_sample_buffer_get_presentation_timestamp_method_ =
+        reinterpret_cast<CMSampleBufferGetPresentationTimeStampMethod>(
+            dlsym(library_handle, "CMSampleBufferGetPresentationTimeStamp"));
+    CHECK(cm_sample_buffer_get_presentation_timestamp_method_) << dlerror();
     k_cm_sample_attachment_key_not_sync_ = reinterpret_cast<CFStringRef*>(
         dlsym(library_handle, "kCMSampleAttachmentKey_NotSync"));
     CHECK(k_cm_sample_attachment_key_not_sync_) << dlerror();
 
     cm_format_description_get_media_sub_type_method_ =
         reinterpret_cast<CMFormatDescriptionGetMediaSubTypeMethod>(
             dlsym(library_handle, "CMFormatDescriptionGetMediaSubType"));
     CHECK(cm_format_description_get_media_sub_type_method_) << dlerror();
     cm_video_format_description_get_dimensions_method_ =
         reinterpret_cast<CMVideoFormatDescriptionGetDimensionsMethod>(
@@ skipping 36 matching lines @@
     return cm_sample_buffer_get_format_description_method_;
   }
   const CMSampleBufferGetImageBufferMethod&
       cm_sample_buffer_get_image_buffer_method() const {
     return cm_sample_buffer_get_image_buffer_method_;
   }
   const CMSampleBufferGetSampleAttachmentsArrayMethod&
   cm_sample_buffer_get_sample_attachments_array_method() const {
     return cm_sample_buffer_get_sample_attachments_array_method_;
   }
+  const CMSampleBufferGetPresentationTimeStampMethod&
+  cm_sample_buffer_get_presentation_timestamp_method() const {
+    return cm_sample_buffer_get_presentation_timestamp_method_;
+  }
   CFStringRef* const& k_cm_sample_attachment_key_not_sync() const {
     return k_cm_sample_attachment_key_not_sync_;
   }
 
   const CMFormatDescriptionGetMediaSubTypeMethod&
       cm_format_description_get_media_sub_type_method() const {
     return cm_format_description_get_media_sub_type_method_;
   }
   const CMVideoFormatDescriptionGetDimensionsMethod&
       cm_video_format_description_get_dimensions_method() const {
@@ skipping 20 matching lines @@
   CMSampleBufferGetSampleAttachmentsArrayMethod
       cm_sample_buffer_get_sample_attachments_array_method_;
   CFStringRef* k_cm_sample_attachment_key_not_sync_;
 
   CMFormatDescriptionGetMediaSubTypeMethod
       cm_format_description_get_media_sub_type_method_;
   CMVideoFormatDescriptionGetDimensionsMethod
       cm_video_format_description_get_dimensions_method_;
   CMVideoFormatDescriptionGetH264ParameterSetAtIndexMethod
       cm_video_format_description_get_h264_parameter_set_at_index_method_;
+  CMSampleBufferGetPresentationTimeStampMethod
+      cm_sample_buffer_get_presentation_timestamp_method_;
 
   DISALLOW_COPY_AND_ASSIGN(CoreMediaLibraryInternal);
 };
 
 }  // namespace
 
 static base::LazyInstance<CoreMediaLibraryInternal> g_coremedia_handle =
     LAZY_INSTANCE_INITIALIZER;
 
 // static
@@ skipping 73 matching lines @@
 // static
 CFArrayRef CoreMediaGlue::CMSampleBufferGetSampleAttachmentsArray(
     CMSampleBufferRef sbuf,
     Boolean createIfNecessary) {
   return g_coremedia_handle.Get()
       .cm_sample_buffer_get_sample_attachments_array_method()(
           sbuf, createIfNecessary);
 }
 
 // static
+CoreMediaGlue::CMTime CoreMediaGlue::CMSampleBufferGetPresentationTimeStamp(
+    CMSampleBufferRef sbuf) {
+  return g_coremedia_handle.Get()
+      .cm_sample_buffer_get_presentation_timestamp_method()(sbuf);
+}
+
+// static
 CFStringRef CoreMediaGlue::kCMSampleAttachmentKey_NotSync() {
   return *g_coremedia_handle.Get().k_cm_sample_attachment_key_not_sync();
 }
 
 // static
 FourCharCode CoreMediaGlue::CMFormatDescriptionGetMediaSubType(
       CMFormatDescriptionRef desc) {
   return g_coremedia_handle.Get()
       .cm_format_description_get_media_sub_type_method()(desc);
 }
@@ skipping 16 matching lines @@
     int* NALUnitHeaderLengthOut) {
   return g_coremedia_handle.Get()
       .cm_video_format_description_get_h264_parameter_set_at_index_method()(
           videoDesc,
           parameterSetIndex,
           parameterSetPointerOut,
           parameterSetSizeOut,
           parameterSetCountOut,
           NALUnitHeaderLengthOut);
 }