Index: media/base/audio_fifo.h |
diff --git a/media/base/audio_fifo.h b/media/base/audio_fifo.h |
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+// 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. |
+ |
+#ifndef MEDIA_BASE_AUDIO_FIFO_H_ |
+#define MEDIA_BASE_AUDIO_FIFO_H_ |
+ |
+#include "media/base/audio_bus.h" |
+#include "media/base/media_export.h" |
+ |
+namespace media { |
+ |
+// First-in first-out container for AudioBus elements. |
+// The maximum number of audio frames in the FIFO is set at construction and |
+// can not be extended dynamically. Each channel is stored in planar format |
+// and guaranteed to be aligned by AudioBus::kChannelAlignment. The allocated |
Chris Rogers
2012/09/04 20:07:20
comment nit: I'd simply remove this comment about
henrika (OOO until Aug 14)
2012/09/05 10:14:36
Done.
|
+// memory is utilized as a circular queue. |
Chris Rogers
2012/09/04 20:07:20
nit: My preference is to avoid the word "queue" an
henrika (OOO until Aug 14)
2012/09/05 10:14:36
Done.
|
+class MEDIA_EXPORT AudioFifo { |
+ public: |
+ // Creates a new AudioFifo and allocates |channels| of length |frames|. |
+ AudioFifo(int channels, int frames); |
+ virtual ~AudioFifo(); |
+ |
+ // Appends all audio channel data from |source| to the FIFO. |
+ // Returns false if the allocated space is not sufficient. |
Chris Rogers
2012/09/04 20:07:20
and I would add that "partial data is not written"
henrika (OOO until Aug 14)
2012/09/05 10:14:36
Done.
|
+ bool Append(const AudioBus* source); |
DaleCurtis
2012/09/05 10:34:18
Do we expect a recoverable / normal case where App
henrika (OOO until Aug 14)
2012/09/05 12:49:04
I discussed this off-line with Chris and his sugge
DaleCurtis
2012/09/05 13:09:22
I'd just prefer to not have to worry about the ret
|
+ |
+ // Removes |destination->frames()| audio frames from the FIFO and copies |
+ // them to |destination|. |
Chris Rogers
2012/09/04 20:07:20
and "Returns false if there's not enough data, not
henrika (OOO until Aug 14)
2012/09/05 10:14:36
Done.
|
+ bool Remove(AudioBus* destination); |
DaleCurtis
2012/09/05 10:34:18
Kind of a misleading name, since it doesn't remove
henrika (OOO until Aug 14)
2012/09/05 12:49:04
Chris and I discussed this as well and landed at t
|
+ |
+ // Empties the FIFO without deallocating any memory. |
+ void Clear(); |
+ |
+ // Helper methods. |
+ int size() const { return size_; } |
Chris Rogers
2012/09/04 20:07:20
I would tend to call this "available()" or "frames
henrika (OOO until Aug 14)
2012/09/05 10:14:36
I will wait for feedback from Dale as well. But av
DaleCurtis
2012/09/05 10:34:18
+1 for frames_available(). size() is inconsistent
henrika (OOO until Aug 14)
2012/09/05 12:49:04
OK, now I understand the point of using available.
|
+ int max_size() const { return audio_bus_->frames(); } |
DaleCurtis
2012/09/05 10:34:18
Needed publicly?
henrika (OOO until Aug 14)
2012/09/05 12:49:04
nope; I just liked it. Will remove.
|
+ int channels() const { return audio_bus_->channels(); } |
DaleCurtis
2012/09/05 10:34:18
Ditto.
henrika (OOO until Aug 14)
2012/09/05 12:49:04
got it, will remove.
|
+ bool empty() const { return (size_ == 0); } |
+ bool full() const { return (size_ == max_size()); } |
DaleCurtis
2012/09/05 10:34:18
Ditto / needed at all?
henrika (OOO until Aug 14)
2012/09/05 12:49:04
I dropped two of them but would like to keep these
DaleCurtis
2012/09/05 13:09:22
Seems you dropped them anyway? If you need them th
|
+ |
+ private: |
+ // The actual FIFO is an audio bus implemented as a circular queue. |
Chris Rogers
2012/09/04 20:07:20
queue -> buffer
henrika (OOO until Aug 14)
2012/09/05 10:14:36
Done.
|
+ scoped_ptr<AudioBus> audio_bus_; |
+ |
+ // Number of actual elements in the FIFO. |
+ int size_; |
Chris Rogers
2012/09/04 20:07:20
size_ -> available_
henrika (OOO until Aug 14)
2012/09/05 10:14:36
I am inspired by:
STL where queue::size() returns
|
+ |
+ // Current read position. |
+ int read_pos_; |
+ |
+ // Current write position. |
+ int write_pos_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(AudioFifo); |
+}; |
+ |
+} // namespace media |
+ |
+#endif // MEDIA_BASE_AUDIO_FIFO_H_ |