AnnexB.h - mozsearch

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/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef DOM_MEDIA_PLATFORMS_AGNOSTIC_BYTESTREAMS_ANNEX_B_H_

#define DOM_MEDIA_PLATFORMS_AGNOSTIC_BYTESTREAMS_ANNEX_B_H_

#include "ErrorList.h"

#include "mozilla/RefPtr.h"

#include "mozilla/Result.h"

template <class>

class nsTArray;

namespace mozilla {

class BufferReader;

class MediaRawData;

class MediaByteBuffer;

class AnnexB {

 public:

  struct NALEntry {

    NALEntry(int64_t aOffset, int64_t aSize) : mOffset(aOffset), mSize(aSize) {

      MOZ_ASSERT(mOffset >= 0);

      MOZ_ASSERT(mSize >= 0);

    // They should be non-negative, so we use int64_t to assert their value when

    // assigning value to them.

    int64_t mOffset;

    int64_t mSize;

};

  // All conversions assume size of NAL length field is 4 bytes.

  // Convert a sample from AVCC format to Annex B.

  static mozilla::Result<mozilla::Ok, nsresult> ConvertAVCCSampleToAnnexB(

      mozilla::MediaRawData* aSample, bool aAddSPS = true);

  // All conversions assume size of NAL length field is 4 bytes.

  // Convert a sample from HVCC format to Annex B.

  static mozilla::Result<mozilla::Ok, nsresult> ConvertHVCCSampleToAnnexB(

      mozilla::MediaRawData* aSample, bool aAddSPS = true);

  // Convert a sample from Annex B to AVCC.

  // an AVCC extradata must not be set.

  static bool ConvertSampleToAVCC(

      mozilla::MediaRawData* aSample,

      const RefPtr<mozilla::MediaByteBuffer>& aAVCCHeader = nullptr);

  // Convert a sample from Annex B to HVCC. An HVCC extradata must not be set.

  static Result<mozilla::Ok, nsresult> ConvertSampleToHVCC(

      mozilla::MediaRawData* aSample);

  // Covert sample to 4 bytes NALU byte stream.

  static mozilla::Result<mozilla::Ok, nsresult> ConvertAVCCTo4BytesAVCC(

      mozilla::MediaRawData* aSample);

  static mozilla::Result<mozilla::Ok, nsresult> ConvertHVCCTo4BytesHVCC(

      mozilla::MediaRawData* aSample);

  // Parse an AVCC extradata and construct the Annex B sample header.

  static already_AddRefed<mozilla::MediaByteBuffer>

  ConvertAVCCExtraDataToAnnexB(const mozilla::MediaByteBuffer* aExtraData);

  // Parse a HVCC extradata and construct the Annex B sample header.

  static already_AddRefed<mozilla::MediaByteBuffer>

  ConvertHVCCExtraDataToAnnexB(const mozilla::MediaByteBuffer* aExtraData);

  // Returns true if format is AVCC and sample has valid extradata.

  static bool IsAVCC(const mozilla::MediaRawData* aSample);

  // Returns true if format is HVCC and sample has valid extradata.

  static bool IsHVCC(const mozilla::MediaRawData* aSample);

  // Returns true if format is AnnexB.

  static bool IsAnnexB(const mozilla::MediaRawData* aSample);

  // Parse NAL entries from the bytes stream to know the offset and the size of

  // each NAL in the bytes stream.

  static void ParseNALEntries(const Span<const uint8_t>& aSpan,

                              nsTArray<AnnexB::NALEntry>& aEntries);

 private:

  // AVCC box parser helper.

  static mozilla::Result<mozilla::Ok, nsresult> ConvertSPSOrPPS(

      mozilla::BufferReader& aReader, uint8_t aCount,

      mozilla::MediaByteBuffer* aAnnexB);

  // NALU size can vary, this function converts the sample to always 4 bytes

  // NALU.

  static mozilla::Result<mozilla::Ok, nsresult> ConvertNALUTo4BytesNALU(

      mozilla::MediaRawData* aSample, uint8_t aNALUSize);

};

}  // namespace mozilla

#endif  // DOM_MEDIA_PLATFORMS_AGNOSTIC_BYTESTREAMS_ANNEX_B_H_