third_party/blink/public/platform/web_source_buffer.h

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef THIRD_PARTY_BLINK_PUBLIC_PLATFORM_WEB_SOURCE_BUFFER_H_
#define THIRD_PARTY_BLINK_PUBLIC_PLATFORM_WEB_SOURCE_BUFFER_H_

#include "media/base/stream_parser.h"
#include "third_party/blink/public/platform/web_string.h"
#include "third_party/blink/public/platform/web_time_range.h"

namespace blink {

class WebSourceBufferClient;

// Interface for actuating the media engine implementation of Media Source
// extension's SourceBuffer. See also the mediasource module in Blink, and the
// WebSourceBufferClient interface.
class WebSourceBuffer {
 public:
  enum AppendMode { kAppendModeSegments, kAppendModeSequence };

  virtual ~WebSourceBuffer() = default;

  // This will only be called once and only with a non-null pointer to a
  // client whose ownership is not transferred to this WebSourceBuffer.
  virtual void SetClient(WebSourceBufferClient*) = 0;

  virtual bool SetMode(AppendMode) = 0;
  virtual bool GetGenerateTimestampsFlag() = 0;
  virtual WebTimeRanges Buffered() = 0;

  // Returns the highest buffered presentation timestamp of all buffered coded
  // frames, or 0 if nothing is buffered.
  virtual double HighestPresentationTimestamp() = 0;

  // Run coded frame eviction/garbage collection algorithm.
  // |current_playback_time| is HTMLMediaElement::currentTime. The algorithm
  // will try to preserve data around current playback position.
  // |new_data_size| is size of new data about to be appended to SourceBuffer.
  // Could be zero for appendStream if stream size is unknown in advance.
  // Returns false if buffer is still full after eviction.
  virtual bool EvictCodedFrames(double current_playback_time,
                                size_t new_data_size) = 0;

  // Intended to be called during the synchronous initial steps of
  // SourceBuffer.appendBuffer(), appends data to internal parser input buffer,
  // but does not do any parsing or execution of the segment parser loop
  // algorithm. Actual parse is done later when caller invokes
  // RunSegmentParserLoop(). Returns true if the addition was successful, false
  // otherwise. Note that a false result here is non-fatal: the parser has not
  // accepted `data` and the caller is expected to throw a recoverable
  // QuotaExceededError to the MSE API user. Before this call, the parser must
  // not still be awaiting RunSegmentParserLoop() call(s). On success, at least
  // one RunSegmentParserLoop() call will be necessary to actually parse the new
  // bytes. Note, for zero-length appendBuffers, the caller can skip this call
  // and just run the segment parser loop asynchronously once.
  [[nodiscard]] virtual bool AppendToParseBuffer(
      base::span<const unsigned char> data) = 0;

  // Intended to be called potentially asynchronously after
  // SourceBuffer.appendBuffer() and potentially repeatedly, runs the segment
  // parser loop algorithm on any data already in the parser input buffer (see
  // AppendToParseBuffer()). The algorithm and associated frame processing may
  // update `*timestamp_offset` if `timestamp_offset` is not null; this offset
  // is in seconds.
  // Returns kSuccess if the segment parser loop iteration succeeded and all
  // previously provided data from AppendToParseBuffer() has been inspected.
  // Returns kSuccessHasMoreData if the segment parser loop iteration succeeded,
  // yet there remains uninspected data remaining from AppendToParseBuffer();
  // more call(s) to this method are necessary for the parser to attempt
  // inspection of that data.
  // Returns kFailed if the segment parser loop iteration hit error and the
  // caller needs to run the append error algorithm with the decode error
  // parameter set to true.
  [[nodiscard]] virtual media::StreamParser::ParseStatus RunSegmentParserLoop(
      double* timestamp_offset) = 0;

  // Processes caller-provided media::StreamParserBuffers. The associated frame
  // processing may update `*timestamp_offset` if `timestamp_offset` is not
  // null; this offset is in seconds.
  // Returns true on success, otherwise the append error algorithm needs to run
  // with the decode error parameter set to true.
  virtual bool AppendChunks(
      std::unique_ptr<media::StreamParser::BufferQueue> buffer_queue,
      double* timestamp_offset) = 0;

  virtual void ResetParserState() = 0;
  virtual void Remove(double start, double end) = 0;

  // Returns true iff this SourceBuffer supports changing bytestream and codecs
  // to |content_type| and |codecs|.  |content_type| is the ContentType string
  // of the bytestream's MIME type, and |codecs| contains the "codecs" parameter
  // string, if any, of the bytestream's MIME type.
  virtual bool CanChangeType(const WebString& content_type,
                             const WebString& codecs) = 0;

  // Updates this SourceBuffer to parse bytestream and codecs |content_type| and
  // |codecs|. Caller must first ensure CanChangeType() returns true for the
  // same parameters, and must call ResetParserState() prior to calling this, to
  // flush any pending frames. See CanChangeType() for description of
  // |content_type| and |codecs| parameters.
  virtual void ChangeType(const WebString& content_type,
                          const WebString& codecs) = 0;

  virtual bool SetTimestampOffset(double) = 0;

  // Set presentation timestamp for the start of append window.
  virtual void SetAppendWindowStart(double) = 0;

  // Set presentation timestamp for the end of append window.
  virtual void SetAppendWindowEnd(double) = 0;

  // After this method is called, this WebSourceBuffer should never use the
  // client pointer passed to SetClient().
  virtual void RemovedFromMediaSource() = 0;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_PUBLIC_PLATFORM_WEB_SOURCE_BUFFER_H_