5.x Linux wheels still cannot decode AV1: 5.0.0.93 predates the dav1d fix (#1209), please release a 5.x build

[OrcVole]

Summary

The Linux AV1 decoding fix from #1209 (which closed #908) is merged into both 4.x and 5.x, but it has only been released on the 4.x line. The newest 5.x wheel on PyPI, 5.0.0.93 (uploaded 2026-07-02), predates the merge (2026-07-27, 314eb3d2), so 5.x users on Linux still cannot read any AV1 video.

Could a 5.x wheel be published that includes the dav1d build from #1209?

Reproduction

Linux x86_64, Python 3.12, wheels from PyPI. Test files made with FFmpeg 8.1:

ffmpeg -f lavfi -i testsrc2=s=640x360:r=25:d=2 -c:v libsvtav1 -pix_fmt yuv420p    av1-8bit.mp4
ffmpeg -f lavfi -i testsrc2=s=640x360:r=25:d=2 -c:v libsvtav1 -pix_fmt yuv420p10le av1-10bit.mp4
ffmpeg -f lavfi -i testsrc2=s=640x360:r=25:d=2 -c:v libx264   -pix_fmt yuv420p    h264.mp4

import cv2
for f in ["av1-8bit.mp4", "av1-10bit.mp4", "h264.mp4"]:
    cap = cv2.VideoCapture(f, cv2.CAP_FFMPEG)
    print(f, "opened:", cap.isOpened(), "read:", cap.read()[0])

Wheel	av1-8bit.mp4	av1-10bit.mp4	h264.mp4
opencv-python-headless==4.14.0.94	read: True	read: True	read: True
opencv-python-headless==5.0.0.93	read: False	read: False	read: True

(opencv-python==5.0.0.93 behaves the same as the headless wheel.)

With 5.0.0.93, isOpened() returns True, so the failure is silent apart from the FFmpeg log:

[av1 @ 0x...] Your platform doesn't support hardware accelerated AV1 decoding.
[av1 @ 0x...] Failed to get pixel format.
[av1 @ 0x...] Get current frame error

Diagnosis

Querying the libavcodec bundled in the 5.0.0.93 wheel (opencv_python.libs/libavcodec-*.so.62.28.101) with avcodec_find_decoder_by_name:

Decoder	Present
av1 (FFmpeg's native decoder, which needs a hwaccel)	yes
libdav1d	no
libaom-av1	no

So there is no software AV1 decoder, which is what #1209 adds. (The wheel does ship a libaom shared object, but libavcodec does not register a decoder for it.)

Workaround

Pin opencv-python(-headless)==4.14.0.94, or transcode to H.264 before reading.

Related

• Problem: Your platform doesn't suppport hardware accelerated AV1 decoding. Failed to get pixel format. #908: original report, closed by Fix VideoCapture not able to read AV1 encoded files on Linux #1209
• Fix VideoCapture not able to read AV1 encoded files on Linux #1209: the fix (dav1d in the manylinux and musllinux images), merged into 4.x and present on 5.x as 314eb3d2