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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 "qffmpegcodec_p.h"
#include "qffmpeg_p.h"
#include <QtCore/qloggingcategory.h>
QT_BEGIN_NAMESPACE
namespace QFFmpeg {
namespace {
template <typename T>
inline constexpr auto InvalidAvValue = T{};
template <>
inline constexpr auto InvalidAvValue<AVSampleFormat> = AV_SAMPLE_FMT_NONE;
template <>
inline constexpr auto InvalidAvValue<AVPixelFormat> = AV_PIX_FMT_NONE;
template <typename T>
QSpan<const T> makeSpan(const T *values)
{
if (!values)
return {};
qsizetype size = 0;
while (values[size] != InvalidAvValue<T>)
++size;
return QSpan<const T>{ values, size };
}
#if QT_FFMPEG_HAS_AVCODEC_GET_SUPPORTED_CONFIG
Q_STATIC_LOGGING_CATEGORY(qLcFFmpegUtils, "qt.multimedia.ffmpeg.utils");
void logGetCodecConfigError(const AVCodec *codec, AVCodecConfig config, int error)
{
qCWarning(qLcFFmpegUtils) << "Failed to retrieve config" << config << "for codec" << codec->name
<< "with error" << error << AVError(error);
}
template <typename T>
QSpan<const T> getCodecConfig(const AVCodec *codec, AVCodecConfig config)
{
const T *result = nullptr;
int size = 0;
const auto error = avcodec_get_supported_config(
nullptr, codec, config, 0u, reinterpret_cast<const void **>(&result), &size);
if (error != 0) {
logGetCodecConfigError(codec, config, error);
return {};
}
// Sanity check of FFmpeg's array layout. If it is not nullptr, it should end with a terminator,
// and be non-empty. A non-null but empty config would mean that no values are accepted by the
// codec, which does not make sense.
Q_ASSERT(!result || (size > 0 && result[size] == InvalidAvValue<T>));
// Returns empty span if 'result' is nullptr. This can be misleading, as it may
// mean that 'any' value is allowed, or that the result is 'unknown'.
return QSpan<const T>{ result, size };
}
#endif
QSpan<const AVPixelFormat> getCodecPixelFormats(const AVCodec *codec)
{
#if QT_FFMPEG_HAS_AVCODEC_GET_SUPPORTED_CONFIG
return getCodecConfig<AVPixelFormat>(codec, AV_CODEC_CONFIG_PIX_FORMAT);
#else
return makeSpan(codec->pix_fmts);
#endif
}
QSpan<const AVSampleFormat> getCodecSampleFormats(const AVCodec *codec)
{
#if QT_FFMPEG_HAS_AVCODEC_GET_SUPPORTED_CONFIG
return getCodecConfig<AVSampleFormat>(codec, AV_CODEC_CONFIG_SAMPLE_FORMAT);
#else
return makeSpan(codec->sample_fmts);
#endif
}
QSpan<const int> getCodecSampleRates(const AVCodec *codec)
{
#if QT_FFMPEG_HAS_AVCODEC_GET_SUPPORTED_CONFIG
return getCodecConfig<int>(codec, AV_CODEC_CONFIG_SAMPLE_RATE);
#else
return makeSpan(codec->supported_samplerates);
#endif
}
#ifdef Q_OS_WINDOWS
auto stereoLayout() // unused function on non-Windows platforms
{
constexpr uint64_t mask = AV_CH_FRONT_LEFT | AV_CH_FRONT_RIGHT;
#if QT_FFMPEG_HAS_AV_CHANNEL_LAYOUT
AVChannelLayout channelLayout{};
av_channel_layout_from_mask(&channelLayout, mask);
return channelLayout;
#else
return mask;
#endif
};
#endif
QSpan<const ChannelLayoutT> getCodecChannelLayouts(const AVCodec *codec)
{
QSpan<const ChannelLayoutT> layout;
#if QT_FFMPEG_HAS_AVCODEC_GET_SUPPORTED_CONFIG
layout = getCodecConfig<AVChannelLayout>(codec, AV_CODEC_CONFIG_CHANNEL_LAYOUT);
#elif QT_FFMPEG_HAS_AV_CHANNEL_LAYOUT
layout = makeSpan(codec->ch_layouts);
#else
layout = makeSpan(codec->channel_layouts);
#endif
#ifdef Q_OS_WINDOWS
// The mp3_mf codec does not report any layout restrictions, but does not
// handle more than 2 channels. We therefore make this explicit here.
if (layout.empty() && QLatin1StringView(codec->name) == QLatin1StringView("mp3_mf")) {
static const ChannelLayoutT defaultLayout[] = { stereoLayout() };
layout = defaultLayout;
}
#endif
return layout;
}
QSpan<const AVRational> getCodecFrameRates(const AVCodec *codec)
{
#if QT_FFMPEG_HAS_AVCODEC_GET_SUPPORTED_CONFIG
return getCodecConfig<AVRational>(codec, AV_CODEC_CONFIG_FRAME_RATE);
#else
return makeSpan(codec->supported_framerates);
#endif
}
} // namespace
Codec::Codec(const AVCodec *codec) : m_codec{ codec }
{
Q_ASSERT(m_codec);
}
const AVCodec* Codec::get() const noexcept
{
Q_ASSERT(m_codec);
return m_codec;
}
AVCodecID Codec::id() const noexcept
{
Q_ASSERT(m_codec);
return m_codec->id;
}
QLatin1StringView Codec::name() const noexcept
{
Q_ASSERT(m_codec);
return QLatin1StringView{ m_codec->name };
}
AVMediaType Codec::type() const noexcept
{
Q_ASSERT(m_codec);
return m_codec->type;
}
// See AV_CODEC_CAP_*
int Codec::capabilities() const noexcept
{
Q_ASSERT(m_codec);
return m_codec->capabilities;
}
bool Codec::isEncoder() const noexcept
{
Q_ASSERT(m_codec);
return av_codec_is_encoder(m_codec) != 0;
}
bool Codec::isDecoder() const noexcept
{
Q_ASSERT(m_codec);
return av_codec_is_decoder(m_codec) != 0;
}
bool Codec::isExperimental() const noexcept
{
Q_ASSERT(m_codec);
return (m_codec->capabilities & AV_CODEC_CAP_EXPERIMENTAL) != 0;
}
QSpan<const AVPixelFormat> Codec::pixelFormats() const noexcept
{
Q_ASSERT(m_codec);
if (m_codec->type != AVMEDIA_TYPE_VIDEO)
return {};
return getCodecPixelFormats(m_codec);
}
QSpan<const AVSampleFormat> Codec::sampleFormats() const noexcept
{
Q_ASSERT(m_codec);
if (m_codec->type != AVMEDIA_TYPE_AUDIO)
return {};
return getCodecSampleFormats(m_codec);
}
QSpan<const int> Codec::sampleRates() const noexcept
{
Q_ASSERT(m_codec);
if (m_codec->type != AVMEDIA_TYPE_AUDIO)
return {};
return getCodecSampleRates(m_codec);
}
QSpan<const ChannelLayoutT> Codec::channelLayouts() const noexcept
{
Q_ASSERT(m_codec);
if (m_codec->type != AVMEDIA_TYPE_AUDIO)
return {};
return getCodecChannelLayouts(m_codec);
}
QSpan<const AVRational> Codec::frameRates() const noexcept
{
Q_ASSERT(m_codec);
if (m_codec->type != AVMEDIA_TYPE_VIDEO)
return {};
return getCodecFrameRates(m_codec);
}
std::vector<const AVCodecHWConfig *> Codec::hwConfigs() const noexcept
{
Q_ASSERT(m_codec);
// For most codecs, hwConfig is empty so we optimize for
// the hot path and do not preallocate/reserve any memory.
std::vector<const AVCodecHWConfig *> configs;
for (int index = 0; auto config = avcodec_get_hw_config(m_codec, index); ++index)
configs.push_back(config);
return configs;
}
const AVCodecHWConfig *Codec::hwConfigForPixelFormat(AVPixelFormat pix) const noexcept
{
Q_ASSERT(m_codec);
for (int index = 0; auto config = avcodec_get_hw_config(m_codec, index); ++index) {
if (config->pix_fmt == pix)
return config;
}
return nullptr;
}
QSpan<const AVPixelFormat> makeSpan(const AVPixelFormat *values)
{
return makeSpan<AVPixelFormat>(values);
}
} // namespace QFFmpeg
QT_END_NAMESPACE