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
12namespace media {
13
14namespace limits {
15
16enum {
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  // Maximum lengths for various EME API parameters. These are checks to
47  // prevent unnecessarily large parameters from being passed around, and the
48  // lengths are somewhat arbitrary as the EME spec doesn't specify any limits.
49  kMinCertificateLength = 128,
50  kMaxCertificateLength = 16 * 1024,
51  kMaxWebSessionIdLength = 512,
52  kMinKeyIdLength = 1,
53  kMaxKeyIdLength = 512,
54  kMaxKeyIds = 128,
55};
56
57}  // namespace limits
58
59}  // namespace media
60
61#endif  // MEDIA_BASE_LIMITS_H_
62