Checking in media::MediaFormat class, which describes the output of a filter.

Review URL: http://codereview.chromium.org/13149

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@6412 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 223 insertions, 1 deletions

diff --git a/media/base/media.cc b/media/base/media.cc
index 92370bf..91486ee 100644
--- a/media/base/media.cc
+++ b/media/base/media.cc
@@ -4,6 +4,7 @@
 
 #include "media/base/buffers.h"
 #include "media/base/filters.h"
+#include "media/base/media_format.h"
 
 namespace media {
 
@@ -11,4 +12,4 @@ namespace media {
 void DoNothing() {
 }
 
-} // namespace media
+}  // namespace media
diff --git a/media/base/media_format.cc b/media/base/media_format.cc
new file mode 100644
index 0000000..c675a73
--- /dev/null
+++ b/media/base/media_format.cc
@@ -0,0 +1,126 @@
+// Copyright (c) 2006-2008 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/media_format.h"
+
+namespace media {
+
+namespace mime_type {
+
+// Represents a URI, typically used to create a DataSourceInterface.
+// Expected keys:
+//   kUri             String          The URI
+const std::wstring kURI(L"text/x-uri");
+
+// Represents a generic byte stream, typically from a DataSourceInterface.
+// Expected keys:
+//   None
+const std::wstring kApplicationOctetStream(L"application/octet-stream");
+
+// Represents encoded audio data, typically from an DemuxerStreamInterface.
+// Expected keys:
+//   None
+const std::wstring kMPEGAudio(L"audio/mpeg");
+const std::wstring kAACAudio(L"audio/aac");
+
+// Represents encoded video data, typically from a DemuxerStreamInterface.
+// Expected keys:
+//   None
+const std::wstring kH264AnnexB(L"video/x-h264-annex-b");
+
+// Represents decoded audio data, typically from an AudioDecoderInterface.
+// Expected keys:
+//   kChannels        Integer         Number of audio channels
+//   kSampleRate      Integer         Audio sample rate (i.e., 44100)
+//   kSampleBits      Integer         Audio bits-per-sample (i.e., 16)
+const std::wstring kRawAudio(L"audio/x-uncompressed");
+
+// Represents decoded video data, typically from a VideoDecoderInterface.
+// Other information, such as surface format (i.e., YV12), stride and planes are
+// included with the buffer itself and is not part of the MediaFormat.
+// Expected keys:
+//   kWidth           Integer         Display width of the surface
+//   kHeight          Integer         Display height of the surface
+const std::wstring kRawVideo(L"video/x-uncompressed");
+
+// Represents FFmpeg encoded packets, typically from an DemuxerStreamInterface.
+// Expected keys:
+//   kFfmpegCodecId   Integer         The FFmpeg CodecID identifying the decoder
+const std::wstring kFFmpegAudio(L"audio/x-ffmpeg");
+const std::wstring kFFmpegVideo(L"video/x-ffmpeg");
+
+}  // namespace mime_type
+
+// Common keys.
+const std::wstring MediaFormat::kMimeType(L"MimeType");
+const std::wstring MediaFormat::kURI(L"Uri");
+const std::wstring MediaFormat::kSurfaceFormat(L"SurfaceFormat");
+const std::wstring MediaFormat::kSampleRate(L"SampleRate");
+const std::wstring MediaFormat::kSampleBits(L"SampleBits");
+const std::wstring MediaFormat::kChannels(L"Channels");
+const std::wstring MediaFormat::kWidth(L"Width");
+const std::wstring MediaFormat::kHeight(L"Height");
+const std::wstring MediaFormat::kFfmpegCodecId(L"FfmpegCodecId");
+
+MediaFormat::MediaFormat() {
+}
+
+MediaFormat::~MediaFormat() {
+  Clear();
+}
+
+bool MediaFormat::Contains(const std::wstring& key) const {
+  return value_map_.find(key) != value_map_.end();
+}
+
+void MediaFormat::Clear() {
+  for (ValueMap::iterator iter(value_map_.begin());
+       iter != value_map_.end(); iter = value_map_.erase(iter))
+    delete iter->second;
+}
+
+void MediaFormat::SetAsBoolean(const std::wstring& key, bool in_value) {
+  value_map_[key] = Value::CreateBooleanValue(in_value);
+}
+
+void MediaFormat::SetAsInteger(const std::wstring& key, int in_value) {
+  value_map_[key] = Value::CreateIntegerValue(in_value);
+}
+
+void MediaFormat::SetAsReal(const std::wstring& key, double in_value) {
+  value_map_[key] = Value::CreateRealValue(in_value);
+}
+
+void MediaFormat::SetAsString(const std::wstring& key,
+                              const std::wstring& in_value) {
+  value_map_[key] = Value::CreateStringValue(in_value);
+}
+
+bool MediaFormat::GetAsBoolean(const std::wstring& key, bool* out_value) const {
+  Value* value = GetValue(key);
+  return value != NULL && value->GetAsBoolean(out_value);
+}
+
+bool MediaFormat::GetAsInteger(const std::wstring& key, int* out_value) const {
+  Value* value = GetValue(key);
+  return value != NULL && value->GetAsInteger(out_value);
+}
+
+bool MediaFormat::GetAsReal(const std::wstring& key, double* out_value) const {
+  Value* value = GetValue(key);
+  return value != NULL && value->GetAsReal(out_value);
+}
+
+bool MediaFormat::GetAsString(const std::wstring& key,
+                              std::wstring* out_value) const {
+  Value* value = GetValue(key);
+  return value != NULL && value->GetAsString(out_value);
+}
+
+Value* MediaFormat::GetValue(const std::wstring& key) const {
+  ValueMap::const_iterator value_iter = value_map_.find(key);
+  return (value_iter == value_map_.end()) ? NULL : value_iter->second;
+}
+
+}  // namespace media
diff --git a/media/base/media_format.h b/media/base/media_format.h
new file mode 100644
index 0000000..d1303a2
--- /dev/null
+++ b/media/base/media_format.h
@@ -0,0 +1,86 @@
+// Copyright (c) 2006-2008 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 MEDIA_BASE_MEDIA_FORMAT_H_
+#define MEDIA_BASE_MEDIA_FORMAT_H_
+
+#include "base/values.h"
+
+namespace media {
+
+// Common MIME types.
+namespace mime_type {
+extern const std::wstring kURI;
+extern const std::wstring kApplicationOctetStream;
+extern const std::wstring kMPEGAudio;
+extern const std::wstring kAACAudio;
+extern const std::wstring kH264AnnexB;
+extern const std::wstring kUncompressedAudio;
+extern const std::wstring kUncompressedVideo;
+extern const std::wstring kFFmpegAudio;
+extern const std::wstring kFFmpegVideo;
+}  // namespace mime_type
+
+// MediaFormat is used to describe the output of a MediaFilterInterface to
+// determine whether a downstream filter can accept the output from an upstream
+// filter.  In general, every MediaFormat contains a MIME type describing
+// its output as well as additional key-values describing additional details.
+//
+// For example, an audio decoder could output audio/x-uncompressed and include
+// additional key-values such as the number of channels and the sample rate.
+// An audio renderer would use this information to properly initialize the
+// audio hardware before playback started.
+//
+// It's also perfectly acceptable to create your own MIME types and standards
+// to allow communication between two filters that goes beyond the basics
+// described here.  For example, you could write a video decoder that outputs
+// a MIME type video/x-special for which your video renderer knows it's some
+// special form of decompressed video output that regular video renderers
+// couldn't handle.
+class MediaFormat {
+ public:
+  // Common keys.
+  static const std::wstring kMimeType;
+  static const std::wstring kURI;
+  static const std::wstring kSurfaceFormat;
+  static const std::wstring kSampleRate;
+  static const std::wstring kSampleBits;
+  static const std::wstring kChannels;
+  static const std::wstring kWidth;
+  static const std::wstring kHeight;
+  static const std::wstring kFfmpegCodecId;
+
+  MediaFormat();
+  ~MediaFormat();
+
+  // Basic map operations.
+  bool empty() const { return value_map_.empty(); }
+
+  bool Contains(const std::wstring& key) const;
+
+  void Clear();
+
+  // Value accessors.
+  void SetAsBoolean(const std::wstring& key, bool in_value);
+  void SetAsInteger(const std::wstring& key, int in_value);
+  void SetAsReal(const std::wstring& key, double in_value);
+  void SetAsString(const std::wstring& key, const std::wstring& in_value);
+
+  bool GetAsBoolean(const std::wstring& key, bool* out_value) const;
+  bool GetAsInteger(const std::wstring& key, int* out_value) const;
+  bool GetAsReal(const std::wstring& key, double* out_value) const;
+  bool GetAsString(const std::wstring& key, std::wstring* out_value) const;
+
+ private:
+  // Helper to return a value.
+  Value* GetValue(const std::wstring& key) const;
+
+  ValueMap value_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaFormat);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_MEDIA_FORMAT_H_
diff --git a/media/build/media.vcproj b/media/build/media.vcproj
index fd20b15..641abc2 100644
--- a/media/build/media.vcproj
+++ b/media/build/media.vcproj
@@ -136,6 +136,14 @@
 				RelativePath="..\base\media.cc"

 				>

 			</File>

+			<File

+				RelativePath="..\base\media_format.cc"

+				>

+			</File>

+			<File

+				RelativePath="..\base\media_format.h"

+				>

+			</File>

 		</Filter>

 	</Files>

 	<Globals>

diff --git a/media/media_lib.scons b/media/media_lib.scons
index ba044e6..9f016c4 100644
--- a/media/media_lib.scons
+++ b/media/media_lib.scons
@@ -26,6 +26,7 @@ env.Prepend(
 # cross-platform live below.
 input_files = [
     'base/media.cc',
+    'base/media_format.cc',
 ]
 
 if env['PLATFORM'] == 'win32':