blob: b251bf7f025e27971417b588a7b0e32a0a0110f4 [file] [log] [blame]
// 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 <stdint.h>
#include <string>
#include <vector>
#include "base/macros.h"
#include "base/time/time.h"
#include "media/base/audio_codecs.h"
#include "media/base/channel_layout.h"
#include "media/base/encryption_scheme.h"
#include "media/base/media_export.h"
#include "media/base/sample_format.h"
namespace media {
// TODO(dalecurtis): FFmpeg API uses |bytes_per_channel| instead of
// |bits_per_channel|, we should switch over since bits are generally confusing
// to work with.
class MEDIA_EXPORT AudioDecoderConfig {
// Constructs an uninitialized object. Clients should call Initialize() with
// appropriate values before using.
// Constructs an initialized object.
AudioDecoderConfig(AudioCodec codec,
SampleFormat sample_format,
ChannelLayout channel_layout,
int samples_per_second,
const std::vector<uint8_t>& extra_data,
const EncryptionScheme& encryption_scheme);
AudioDecoderConfig(const AudioDecoderConfig& other);
// Resets the internal state of this object. |codec_delay| is in frames.
void Initialize(AudioCodec codec,
SampleFormat sample_format,
ChannelLayout channel_layout,
int samples_per_second,
const std::vector<uint8_t>& extra_data,
const EncryptionScheme& encryption_scheme,
base::TimeDelta seek_preroll,
int codec_delay);
// Returns true if this object has appropriate configuration values, false
// otherwise.
bool IsValidConfig() const;
// Returns true if all fields in |config| match this config.
// Note: The contents of |extra_data_| are compared not the raw pointers.
bool Matches(const AudioDecoderConfig& config) const;
// Returns a human-readable string describing |*this|.
std::string AsHumanReadableString() const;
// Sets the number of channels if |channel_layout_| is CHANNEL_LAYOUT_DISCRETE
void SetChannelsForDiscrete(int channels);
AudioCodec codec() const { return codec_; }
int bits_per_channel() const { return bytes_per_channel_ * 8; }
int bytes_per_channel() const { return bytes_per_channel_; }
ChannelLayout channel_layout() const { return channel_layout_; }
int channels() const { return channels_; }
int samples_per_second() const { return samples_per_second_; }
SampleFormat sample_format() const { return sample_format_; }
int bytes_per_frame() const { return bytes_per_frame_; }
base::TimeDelta seek_preroll() const { return seek_preroll_; }
int codec_delay() const { return codec_delay_; }
// Optional byte data required to initialize audio decoders such as Vorbis
// codebooks.
const std::vector<uint8_t>& extra_data() const { return extra_data_; }
// Whether the audio stream is potentially encrypted.
// Note that in a potentially encrypted audio stream, individual buffers
// can be encrypted or not encrypted.
bool is_encrypted() const { return encryption_scheme_.is_encrypted(); }
// Encryption scheme used for encrypted buffers.
const EncryptionScheme& encryption_scheme() const {
return encryption_scheme_;
// Sets the config to be encrypted or not encrypted manually. This can be
// useful for decryptors that decrypts an encrypted stream to a clear stream.
void SetIsEncrypted(bool is_encrypted);
bool should_discard_decoder_delay() const {
return should_discard_decoder_delay_;
void disable_discard_decoder_delay() {
should_discard_decoder_delay_ = false;
// Optionally set by renderer to provide hardware layout when playback
// starts. Intentionally not part of IsValid(). Layout is not updated for
// device changes - use with care!
void set_target_output_channel_layout(ChannelLayout output_layout) {
target_output_channel_layout_ = output_layout;
ChannelLayout target_output_channel_layout() const {
return target_output_channel_layout_;
AudioCodec codec_ = kUnknownAudioCodec;
SampleFormat sample_format_ = kUnknownSampleFormat;
int bytes_per_channel_ = 0;
int samples_per_second_ = 0;
int bytes_per_frame_ = 0;
std::vector<uint8_t> extra_data_;
EncryptionScheme encryption_scheme_;
// Layout and count of the *stream* being decoded.
ChannelLayout channel_layout_ = CHANNEL_LAYOUT_UNSUPPORTED;
int channels_ = 0;
// Layout of the output hardware. Optionally set. See setter comments.
ChannelLayout target_output_channel_layout_ = CHANNEL_LAYOUT_NONE;
// |seek_preroll_| is the duration of the data that the decoder must decode
// before the decoded data is valid.
base::TimeDelta seek_preroll_;
// |codec_delay_| is the number of frames the decoder should discard before
// returning decoded data. This value can include both decoder delay as well
// as padding added during encoding.
int codec_delay_ = 0;
// Indicates if a decoder should implicitly discard decoder delay without it
// being explicitly marked in discard padding.
bool should_discard_decoder_delay_ = true;
// Not using DISALLOW_COPY_AND_ASSIGN here intentionally to allow the compiler
// generated copy constructor and assignment operator. Since the extra data is
// typically small, the performance impact is minimal.
} // namespace media