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      1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // Contains limit definition constants for the media subsystem.
      6 
      7 #ifndef MEDIA_BASE_LIMITS_H_
      8 #define MEDIA_BASE_LIMITS_H_
      9 
     10 #include "base/basictypes.h"
     11 
     12 namespace media {
     13 
     14 namespace limits {
     15 
     16 enum {
     17   // Maximum possible dimension (width or height) for any video.
     18   kMaxDimension = (1 << 15) - 1,  // 32767
     19 
     20   // Maximum possible canvas size (width multiplied by height) for any video.
     21   kMaxCanvas = (1 << (14 * 2)),  // 16384 x 16384
     22 
     23   // Total number of video frames which are populating in the pipeline.
     24   kMaxVideoFrames = 4,
     25 
     26   // The following limits are used by AudioParameters::IsValid().
     27   //
     28   // A few notes on sample rates of common formats:
     29   //   - AAC files are limited to 96 kHz.
     30   //   - MP3 files are limited to 48 kHz.
     31   //   - Vorbis used to be limited to 96 KHz, but no longer has that
     32   //     restriction.
     33   //   - Most PC audio hardware is limited to 192 KHz.
     34   kMaxSampleRate = 192000,
     35   kMinSampleRate = 3000,
     36   kMaxChannels = 32,
     37   kMaxBytesPerSample = 4,
     38   kMaxBitsPerSample = kMaxBytesPerSample * 8,
     39   kMaxSamplesPerPacket = kMaxSampleRate,
     40   kMaxPacketSizeInBytes =
     41       kMaxBytesPerSample * kMaxChannels * kMaxSamplesPerPacket,
     42 
     43   // This limit is used by ParamTraits<VideoCaptureParams>.
     44   kMaxFramesPerSecond = 1000,
     45 };
     46 
     47 }  // namespace limits
     48 
     49 }  // namespace media
     50 
     51 #endif  // MEDIA_BASE_LIMITS_H_
     52