qffmpegmuxer.cpp - mozsearch

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// Copyright (C) 2024 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include "qffmpegmuxer_p.h"

#include "qffmpegrecordingengine_p.h"

#include "qffmpegrecordingengineutils_p.h"

#include <QtCore/qloggingcategory.h>

QT_BEGIN_NAMESPACE

namespace QFFmpeg {

Q_STATIC_LOGGING_CATEGORY(qLcFFmpegMuxer, "qt.multimedia.ffmpeg.muxer");

Muxer::Muxer(RecordingEngine *encoder) : m_encoder(encoder)

    setObjectName(QLatin1String("Muxer"));

void Muxer::addPacket(AVPacketUPtr packet)

        QMutexLocker locker = lockLoopData();

        m_packetQueue.push(std::move(packet));

    //    qCDebug(qLcFFmpegEncoder) << "Muxer::addPacket" << packet->pts << packet->stream_index;

    dataReady();

AVPacketUPtr Muxer::takePacket()

    QMutexLocker locker = lockLoopData();

    return dequeueIfPossible(m_packetQueue);

bool Muxer::init()

    qCDebug(qLcFFmpegMuxer) << "Muxer::init started thread.";

    return true;

void Muxer::cleanup()

    while (!m_packetQueue.empty())

        processOne();

    const int status = av_interleaved_write_frame(m_encoder->avFormatContext(), nullptr);

    if (status < 0)

        qCWarning(qLcFFmpegMuxer) << "Failed to flush muxer:" << AVError(status);

bool QFFmpeg::Muxer::hasData() const

    return !m_packetQueue.empty();

void Muxer::processOne()

    auto packet = takePacket();

    //   qCDebug(qLcFFmpegEncoder) << "writing packet to file" << packet->pts << packet->duration <<

    //   packet->stream_index;

    // from AVPacket Struct Reference:

    // "The semantics of data ownership depends on the buf field. If it is set, the packet data is

    // dynamically allocated and is valid indefinitely until a call to av_packet_unref() reduces the

    // reference count to 0."

//

    // from av_interleaved_write_frame:

    // "If the packet is reference-counted, this function will take ownership of this reference and

    // unreference it later when it sees fit. The caller must not access the data through this

    // reference after this function returns. If the packet is not reference-counted, libavformat

    // will make a copy."

//

    // This means that av_interleaved_write_frame takes ownership of the AVBufferRef field, not the

    // whole AVPacket.

    const int status = av_interleaved_write_frame(m_encoder->avFormatContext(), packet.get());

    if (status < 0)

        qCWarning(qLcFFmpegMuxer) << "Failed to write packet to file:" << AVError(status);

    Q_ASSERT(packet->buf == nullptr); // av_interleaved_write_frame took ownership of the buffer

} // namespace QFFmpeg

QT_END_NAMESPACE