Add a libvpx video decoder to ClearKeyCdm and move the fake video decoder to its own class.

webkit/media/crypto/ppapi/cdm_video_decoder.cc

+// Copyright (c) 2012 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 "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "webkit/media/crypto/ppapi/cdm_video_decoder.h"
+#include "webkit/media/crypto/ppapi/content_decryption_module.h"
+
+#if defined(CLEAR_KEY_CDM_USE_FAKE_VIDEO_DECODER)
+#include "webkit/media/crypto/ppapi/fake_cdm_video_decoder.h"
+#endif
+
+#if defined(CLEAR_KEY_CDM_USE_FFMPEG_DECODER)
+#include "webkit/media/crypto/ppapi/ffmpeg_cdm_video_decoder.h"
+#endif
+
+#if defined(CLEAR_KEY_CDM_USE_LIBVPX_DECODER)
+#include "webkit/media/crypto/ppapi/libvpx_cdm_video_decoder.h"
+#endif
+
+namespace webkit_media {
+
+scoped_ptr<CdmVideoDecoder> CreateVideoDecoder(
+    cdm::Allocator* allocator,
+    const cdm::VideoDecoderConfig& config) {
+  scoped_ptr<CdmVideoDecoder> video_decoder;
+#if defined(CLEAR_KEY_CDM_USE_FAKE_VIDEO_DECODER)

[xhwang, 2012/11/20 06:46:20]

I wonder if we can use getenv() to make this a runtime option. For example, if
CLEAR_KEY_CDM_USE_FAKE_VIDEO_DECODER is defined in environment variable, then
use the fake decoder. If CLEAR_KEY_CDM_USE_LIBVPX_DECODER is defined, then use
vpx. By default, we use ffmpeg. This way, we can avoid making changes to the gyp
file, avoid the #if/#else mess here, and we don't need to rebuild the CDM if I
want to test something else. WDYT?

[Tom Finegan, 2012/12/03 23:48:55]

The only problem I see with doing it the way you suggest is that we'll always be
linking in all of the decoders instead of only those we need. The CDM will be
bigger...

Anyway, I like the suggestion, but I don't think we should make the change in
this CL. I would prefer to get this landed, clean up the fake audio decoder
stuff, and then do the getenv() stuff.

What do you guys think?

[xhwang, 2012/12/04 01:31:03]

I don't think it an issue to linkin all decoders for a test plugin. But I'll
leave this discussion to ddorwin :)

[ddorwin, 2012/12/04 04:22:37]

Right, we're not worried about size since we never ship this (and the impact on
build time should be minimal since we already build these decoders).

I agree that we should hold off since we're pretty much at LG with this CL and
the suggestion is an optimization.

Caveats:
* Can we pass random environment variables that are accessible within the
sandbox? If not, it's not an option as proposed, but maybe there is something we
can do.
* We'd need to use base/ for obtaining the environment variables across
platforms.
* Would the code actually be considerably simpler? Would we end up with if
statements instead of ifdefs? I agree that ifdefs are really hard to read,
though.

+  video_decoder.reset(new FakeCdmVideoDecoder(allocator));
+
+  if (!video_decoder->Initialize(config))
+    video_decoder.reset();
+#else
+
+#if defined(CLEAR_KEY_CDM_USE_LIBVPX_DECODER)
+  if (config.codec == cdm::VideoDecoderConfig::kCodecVp8) {
+    video_decoder.reset(new LibvpxCdmVideoDecoder(allocator));
+
+    if (!video_decoder->Initialize(config))
+      video_decoder.reset();
+
+    return video_decoder.Pass();
+  }
+#endif
+
+#if defined(CLEAR_KEY_CDM_USE_FFMPEG_DECODER)
+  video_decoder.reset(new FFmpegCdmVideoDecoder(allocator));
+
+  if (!video_decoder->Initialize(config))
+    video_decoder.reset();
+#endif
+
+#endif  // CLEAR_KEY_CDM_USE_FAKE_VIDEO_DECODER
+
+  return video_decoder.Pass();
+}
+
+}  // namespace webkit_media