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// Copyright 2018 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_WAITING_H_
#define MEDIA_BASE_WAITING_H_
#include "base/callback_forward.h"
namespace media {
// Here "waiting" refers to the state that media pipeline stalls waiting because
// of some reason, e.g. no decryption key. It could cause Javascript events like
// "waitingforkey" [1], but not necessarily.
// Note: this generally does not cause the "waiting" event on HTML5 media
// elements [2], which is tightly related to the buffering state change (see
// buffering_state.h).
// [1] https://www.w3.org/TR/encrypted-media/#dom-evt-waitingforkey
// [2]
// https://www.w3.org/TR/html5/semantics-embedded-content.html#eventdef-media-waiting
enum class WaitingReason {
// The playback cannot start because "Media Data May Contain Encrypted Blocks"
// and no CDM is available. The playback will start after a CDM is set. See
// https://www.w3.org/TR/encrypted-media/#media-may-contain-encrypted-blocks
kNoCdm,
// The playback cannot proceed because some decryption key is not available.
// This could happen when the license exchange is delayed or failed. The
// playback will resume after the decryption key becomes available.
// See https://www.w3.org/TR/encrypted-media/#encrypted-block-encountered
kNoDecryptionKey,
// The playback cannot proceed because the decoder has lost its state, e.g.
// information about reference frames. Usually this only happens to hardware
// decoders. To recover from this state, reset the decoder and start decoding
// from a key frame, which can typically be accomplished by a pipeline seek.
kDecoderStateLost,
// Must be assigned with the last enum value above.
kMaxValue = kDecoderStateLost,
};
// Callback to notify waiting state and the reason.
using WaitingCB = base::RepeatingCallback<void(WaitingReason)>;
} // namespace media
#endif // MEDIA_BASE_WAITING_H_
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