5_multimedia/5_1_media-codecs.md

5.1. Media Codecs

5.1.1. Audio Encoding

See more details in 5.1.3. Audio Codecs Details.

If device implementations declare android.hardware.microphone, they MUST support the following audio encoding:

[C-1-1] PCM/WAVE

5.1.2. Audio Decoding

See more details in 5.1.3. Audio Codecs Details.

If device implementations declare support for the android.hardware.audio.output feature, they must support decoding the following audio formats:

[C-1-1] MPEG-4 AAC Profile (AAC LC)
[C-1-2] MPEG-4 HE AAC Profile (AAC+)
[C-1-3] MPEG-4 HE AACv2 Profile (enhanced AAC+)
[C-1-4] AAC ELD (enhanced low delay AAC)
[C-1-11] xHE-AAC (ISO/IEC 23003-3 Extended HE AAC Profile, which includes the USAC Baseline Profile, and ISO/IEC 23003-4 Dynamic Range Control Profile)
[C-1-5] FLAC
[C-1-6] MP3
[C-1-7] MIDI
[C-1-8] Vorbis
[C-1-9] PCM/WAVE
[C-1-10] Opus

If device implementations support the decoding of AAC input buffers of multichannel streams (i.e. more than two channels) to PCM through the default AAC audio decoder in the android.media.MediaCodec API, the following MUST be supported:

[C-2-1] Decoding MUST be performed without downmixing (e.g. a 5.0 AAC stream must be decoded to five channels of PCM, a 5.1 AAC stream must be decoded to six channels of PCM).
[C-2-2] Dynamic range metadata MUST be as defined in “Dynamic Range Control (DRC)” in ISO/IEC 14496-3, and the android.media.MediaFormat DRC keys to configure the dynamic range-related behaviors of the audio decoder. The AAC DRC keys were introduced in API 21,and are: KEY_AAC_DRC_ATTENUATION_FACTOR, KEY_AAC_DRC_BOOST_FACTOR, KEY_AAC_DRC_HEAVY_COMPRESSION, KEY_AAC_DRC_TARGET_REFERENCE_LEVEL and KEY_AAC_ENCODED_TARGET_LEVEL.

When decoding USAC audio, MPEG-D (ISO/IEC 23003-4):

[C-3-1] Loudness and DRC metadata MUST be interpreted and applied according to MPEG-D DRC Dynamic Range Control Profile Level 1.
[C-3-2] The decoder MUST behave according to the configuration set with the following android.media.MediaFormat keys: KEY_AAC_DRC_TARGET_REFERENCE_LEVEL and KEY_AAC_DRC_EFFECT_TYPE.

MPEG-4 AAC, HE AAC, and HE AACv2 profile decoders:

MAY support loudness and dynamic range control using ISO/IEC 23003-4 Dynamic Range Control Profile.

If ISO/IEC 23003-4 is supported and if both ISO/IEC 23003-4 and ISO/IEC 14496-3 metadata are present in a decoded bitstream, then:

ISO/IEC 23003-4 metadata SHALL take precedence.

5.1.3. Audio Codecs Details

Profile (enhanced AAC+) Support for mono/stereo/5.0/5.1 content with standard sampling rates from 16 to 48 kHz.

5.1.4. Image Encoding

See more details in 5.1.6. Image Codecs Details.

Device implementations MUST support encoding the following image encoding:

[C-0-1] JPEG
[C-0-2] PNG
[C-0-3] WebP

5.1.5. Image Decoding

See more details in 5.1.6. Image Codecs Details.

Device impelementations MUST support decoding the following image encoding:

[C-0-1] JPEG
[C-0-2] GIF
[C-0-3] PNG
[C-0-4] BMP
[C-0-5] WebP
[C-0-6] Raw
[C-0-7] HEIF (HEIC)

5.1.6. Image Codecs Details

5.1.7. Video Codecs

For acceptable quality of web video streaming and video-conference services, device implementations SHOULD use a hardware VP8 codec that meets the requirements.

If device implementations include a video decoder or encoder:

[C-1-1] Video codecs MUST support output and input bytebuffer sizes that accommodate the largest feasible compressed and uncompressed frame as dictated by the standard and configuration but also not overallocate.
[C-1-2] Video encoders and decoders MUST support YUV420 flexible color format (COLOR_FormatYUV420Flexible).

If device implementations advertise HDR profile support through Display.HdrCapabilities, they:

[C-2-1] MUST support HDR static metadata parsing and handling.

If device implementations advertise intra refresh support through FEATURE_IntraRefresh in the MediaCodecInfo.CodecCapabilities class, they:

[C-3-1] MUST support the refresh periods in the range of 10 - 60 frames and accurately operate within 20% of configured refresh period.