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NXP i.MX95

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Introduction

The i.MX95 includes a Video Processing Unit (VPU) that provides hardware-accelerated video encoding and decoding for selected codecs. On this platform, the VPU is exposed through the standard Video4Linux2 (V4L2) interface rather than through a dedicated user-space VPU library.

This is an important difference compared to other i.MX families. While other platforms may expose SoC-specific VPU libraries, the i.MX95 follows the approach where the VPU is controlled through V4L2-compliant interfaces and is typically used from multimedia frameworks such as GStreamer.

GStreamer Integration

For i.MX95, the VPU is typically accessed through V4L2-based GStreamer plugins.

The hardware encoder plugins explicitly documented for i.MX95 are:

v4l2h264enc: VPU-based AVC/H.264 encoder
v4l2h265enc: VPU-based HEVC/H.265 encoder

VPU-backed decoding is also possible through V4L2 decoder elements such as v4l2h264dec.

Supported Video Codec Capabilities

The following table summarizes the i.MX95 VPU codec capabilities taken from NXP documentation.

i.MX95 VPU codec capabilities
Function	Codec	Profile	Max Bit Rate	Min Resolution	Max Resolution	Maximum Frame Rate	Portrait Mode	Notes
Decode	HEVC	Main	100 Mbps	64 x 64	4096 x 2304	60 fps at 3840 x 2160	Yes	-
Decode	H.264	HP / MP / BP	50 Mbps	64 x 64	4096 x 2304	60 fps at 3840 x 2160	Yes	-
Decode	MJPEG	-	-	64 x 64	4096 x 2160	30 fps at 3840 x 2160	Yes	400 MSample/s; maximum JPEG image resolution is 8192 x 8192
Encode	H.264	HP / MP / BP	20 Mbps	256 x 128	4096 x 2304	60 fps at 3840 x 2160	No	-
Encode	H.265	Main	-	256 x 128	4096 x 2304	60 fps at 3840 x 2160	No	-
Encode	MJPEG	-	-	64 x 64	4096 x 2160	15 fps at 3840 x 2160	Yes	Maximum JPEG image resolution is 8192 x 8192

Typical Usage on i.MX95

Video Encoding from Raw Frames

For raw video input, the user guide recommends the following structure for i.MX95:

gst-launch-1.0 filesrc location=test.yuyv !   rawvideoparse format=2 width=1920 height=1080 framerate=30/1 colorimetry=bt601 !   v4l2h264enc ! h264parse ! qtmux ! filesink location=output.mp4

For HEVC/H.265:

gst-launch-1.0 filesrc location=test.yuyv ! rawvideoparse format=2 width=1920 height=1080 framerate=30/1 colorimetry=bt601 ! v4l2h265enc ! h265parse ! qtmux ! filesink location=output.mp4

The same encoded stream can also be written to other container formats by replacing the muxer, for example:

qtmux for MP4/MOV
matroskamux for MKV
mpegtsmux for TS

Hardware-Accelerated Decode and Display

For H.264 content in MP4 format:

gst-launch-1.0 filesrc location=input.mp4 \
! qtdemux ! h264parse ! v4l2h264dec ! waylandsink

Decode with Downscaling

The user guide provides a VPU-assisted downscaling example for i.MX95, converting a 1920x1080 H.264 stream to 720x480. On systems without aiurdemux, the equivalent MP4 pipeline uses qtdemux:

gst-launch-1.0 filesrc location=1080p.mp4 \
! qtdemux ! h264parse ! v4l2h264dec ! video/x-raw,width=720,height=480 ! waylandsink

H.264 Transcoding

The documented transcoding flow for i.MX95 is based on hardware decode followed by hardware encode. For MP4 input:

gst-launch-1.0 filesrc location=input.mp4 typefind=true \
! qtdemux ! h264parse ! v4l2h264dec ! queue ! v4l2h264enc ! h264parse \
! matroskamux ! filesink location=output.mkv

This pipeline shows the intended VPU usage model on i.MX95:

decode using a V4L2-backed hardware decoder
re-encode using a V4L2-backed hardware encoder
insert the appropriate parser before the muxer when required

H.264 Transcoding from MPEG-TS

For a transport stream source, replace the demuxer accordingly:

gst-launch-1.0 filesrc location=input.ts \
! tsdemux ! h264parse ! v4l2h264dec ! queue ! v4l2h264enc ! h264parse \
! matroskamux ! filesink location=output.mkv

H.264 Transcoding from Matroska

For MKV input:

gst-launch-1.0 filesrc location=input.mkv \
! matroskademux ! h264parse ! v4l2h264dec ! queue ! v4l2h264enc ! h264parse \
! qtmux ! filesink location=output.mp4

Encoding Camera Capture to H.264

When the input is raw video from a V4L2 capture device, the VPU encoder can be used directly:

gst-launch-1.0 v4l2src device=/dev/video3 \
! video/x-raw,width=1920,height=1080,framerate=30/1 \
! v4l2h264enc ! h264parse ! qtmux ! filesink location=capture.mp4