harmony 鸿蒙Obtaining Supported Codecs

2023-10-30
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Obtaining Supported Codecs

Different devices support different codecs. Before invoking or configuring a codec, you need to query the codec specifications supported.

You can call the native APIs provided by the AVCapability module to check whether related capabilities are supported.

How to Develop

Read AVCapability for the API reference.

Obtain a codec capability instance.

// Obtain a codec capability instance based on the MIME type and encoder flag.
OH_AVCapability *capability = OH_AVCodec_GetCapability(OH_AVCODEC_MIMETYPE_VIDEO_AVC, false);


// Obtain a codec capability instance based on the MIME type, encoder flag, and software/hardware type.
OH_AVCapability *capability = OH_AVCodec_GetCapabilityByCategory(OH_AVCODEC_MIMETYPE_VIDEO_AVC, false, SOFTWARE);

Query the specifications provided by the codec capability instance.

// Check whether the codec capability instance describes a hardware codec.
bool isHardware = OH_AVCapability_IsHardware(capability);


// Obtain the codec name of the codec capability instance.
const char *codecName = OH_AVCapability_GetName(capability);


// Obtain the maximum number of instances supported by the codec capability instance.
int32_t maxSupportedInstances = OH_AVCapability_GetMaxSupportedInstances(capability);


// Obtain the bit rate range supported by the encoder.
OH_AVRange bitrateRange;
int32_t ret = OH_AVCapability_GetEncoderBitrateRange(capability, &bitrateRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Check whether the codec capability instance supports a specific bit rate mode.
bool isEncoderBitrateModeSupported = OH_AVCapability_IsEncoderBitrateModeSupported(capability, BITRATE_MODE_CBR);


// Obtain the quality range supported by the encoder.
OH_AVRange qualityRange;
int32_t ret = OH_AVCapability_GetEncoderQualityRange(capability, &qualityRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the complexity range supported by the encoder.
OH_AVRange complexityRange;
int32_t ret = OH_AVCapability_GetEncoderComplexityRange(capability, &complexityRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the supported audio sampling rates.
const int32_t *sampleRates;
uint32_t sampleRateNum = 0;
int32_t ret = OH_AVCapability_GetAudioSupportedSampleRates(capability, &sampleRates, &sampleRateNum);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the number of audio channels supported.
OH_AVRange channelCountRange;
int32_t ret = OH_AVCapability_GetAudioChannelCountRange(capability, &channelCountRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the width alignment value supported.
int32_t widthAlignment;
int32_t ret = OH_AVCapability_GetVideoWidthAlignment(capability, &widthAlignment);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the height alignment value supported.
int32_t heightAlignment;
int32_t ret = OH_AVCapability_GetVideoHeightAlignment(capability, &heightAlignment);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the width range when the height is 1080.
OH_AVRange widthRange;
int32_t ret = OH_AVCapability_GetVideoWidthRangeForHeight(capability, 1080, &widthRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the height range when the width is 1920.
OH_AVRange heightRange;
int32_t ret = OH_AVCapability_GetVideoHeightRangeForWidth(capability, 1920, &heightRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the width range supported.
OH_AVRange widthRange;
int32_t ret = OH_AVCapability_GetVideoWidthRange(capability, &widthRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the height range supported.
OH_AVRange heightRange;
int32_t ret = OH_AVCapability_GetVideoWidthRange(capability, &heightRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Check whether the codec capability instance supports the 1080p resolution.
bool isVideoSizeSupported = OH_AVCapability_IsVideoSizeSupported(capability, 1920, 1080);


// Obtain the video frame rate range supported.
OH_AVRange frameRateRange;
int32_t ret = OH_AVCapability_GetVideoFrameRateRange(capability, &frameRateRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the video frame rate range when the resolution is 1920 x 1080.
OH_AVRange frameRateRange;
int32_t ret =  OH_AVCapability_GetVideoFrameRateRangeForSize(capability, 1920, 1080, &frameRateRange);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Check whether the codec capability instance supports the scenario where the resolution is 1080p and the frame rate is 30 fps.
bool areVideoSizeAndFrameRateSupported = OH_AVCapability_AreVideoSizeAndFrameRateSupported(capability, 1920, 1080, 30);


// Obtain the supported color formats and the number of supported color formats.
const int32_t *pixFormats;
uint32_t pixFormatNum = 0;
int32_t ret = OH_AVCapability_GetVideoSupportedPixelFormats(capability, &pixFormats, &pixFormatNum);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the profiles supported.
const int32_t *profiles;
uint32_t profileNum = 0;
int32_t ret =  OH_AVCapability_GetSupportedProfiles(capability, &profiles, &profileNum);
if (ret != AV_ERR_OK) {
    // Exception processing.
}


// Obtain the level range of a specific profile.
const int32_t *levels;
uint32_t levelNum = 0;
int32_t ret = OH_AVCapability_GetSupportedLevelsForProfile(capability, 0, &levels, &levelNum);


// Check whether the codec capability instance supports the combination of a profile and level.
bool areProfileAndLevelSupported = OH_AVCapability_AreProfileAndLevelSupported(capability, AVC_PROFILE_BASELINE, 1);