decoder-errata.txt

This file serves to document some of the decoder errata when using MediaCodec hardware decoders on certain devices.

1. num_ref_frames is set to 16 by NVENC which causes decoders to allocate 16+ buffers. This can cause an error or lag on some devices.
	- Affected decoders: TI OMAP4, Allwinner A20
	
2. Some decoders have a huge per-frame latency with the unmodified SPS sent from NVENC. Setting max_dec_frame_buffering fixes this latency issue.
	- Affected decoders: NVIDIA Tegra 3 and 4, Broadcom VideoCore IV

3. Some decoders strictly require that you pass BUFFER_FLAG_CODEC_CONFIG and crash upon the IDR frame if you don't
	- Affected decoders: TI OMAP4

4. Some decoders require num_ref_frames=1 and max_dec_frame_buffering=1 to avoid crashing on SPS on first I-frame
	- Affected decoders: Qualcomm in GS3 on 4.3+, Exynos 4 at 1080p only

5. Some decoders will hang or crash if max_dec_frame_buffering is not present and level_idc is >= 50
	- Affected decoders: MediaTek decoder in Fire HD 6/7 (2014)
	
6. Some decoders will hang if max_dec_frame_buffering IS present
	- Affected decoders: Exynos 5 in Galaxy Note 10.1 (2014)

7. Some decoders will not enter low latency mode if adaptive playback is enabled
	- Affected decoders: Intel decoder in Nexus Player

8. Some decoders will not enter low latency mode if the profile isn't baseline in the first SPS because B-frames may be present.
	- Affected decoders: Intel decoder in Nexus Player (prior to Android 6.0)

9. Some decoders will not enter low latency mode if the profile isn't constrained high profile because B-frames may be present.
	- Affected decoders: Intel decoder in Nexus Player (after Android 6.0)

10. Some decoders actually suffer increased latency when max_dec_frame_buffering=1
	- Affected decoders: MediaTek decoder in Fire TV 2015