I’m running Channels DVR inside an LXC on Proxmox, and everything works perfectly except browser playback. Live TV works, app playback works, transcoding works, and hardware acceleration is active — but browser playback fails immediately.
My hardware is a Minisforum system with an Intel Core Ultra 125H (Intel Arc Graphics 140T).
This GPU uses Intel’s newer iHD VAAPI driver (intel-media-va-driver-non-free).
The issue appears to be specific to the FFmpeg parameters used for browser HLS transcoding. Other transcoding paths work fine.
Here’s the relevant transcoder log from a failed browser playback attempt:
2026/03/04 23:12:23.390325 [ENC] Starting encoder for ch8.1 in /mnt/DVR/Streaming/sessions/ch8.1-dANY-ip192.168.0.101-1206237781/encoder-1-2739513289 at 1 (1.136100) (encoder=h264_vaapi, codec=h264, acodec=aac, resolution=1080, deinterlacer=hardware, bitrate=9488, segment_size=0.01)
2026/03/04 23:12:24.390063 [HLS] ffmpeg: ch8.1-dANY-ip192.168.0.101-1-h264-aac---9488-256-1080-6-0---false-false-0.01-0: [h264_vaapi @ 0x46a41d80] Failed to map output buffers: 24 (internal encoding error).
2026/03/04 23:12:24.390091 [HLS] ffmpeg: ch8.1-dANY-ip192.168.0.101-1-h264-aac---9488-256-1080-6-0---false-false-0.01-0: [h264_vaapi @ 0x46a41d80] Output failed: -5.
2026/03/04 23:12:24.390094 [HLS] ffmpeg: ch8.1-dANY-ip192.168.0.101-1-h264-aac---9488-256-1080-6-0---false-false-0.01-0: [vost#0:0/h264_vaapi @ 0x46a418c0] Error submitting video frame to the encoder
2026/03/04 23:12:24.395145 [HLS] ffmpeg: ch8.1-dANY-ip192.168.0.101-1-h264-aac---9488-256-1080-6-0---false-false-0.01-0: [aac @ 0x46a3e000] 2 frames left in the queue on closing
2026/03/04 23:12:24.395307 [HLS] ffmpeg: ch8.1-dANY-ip192.168.0.101-1-h264-aac---9488-256-1080-6-0---false-false-0.01-0: [aac @ 0x46a40e80] 2 frames left in the queue on closing
2026/03/04 23:12:24.451375 [ENC] Encoder stopped for ch8.1 in /mnt/DVR/Streaming/sessions/ch8.1-dANY-ip192.168.0.101-1206237781/encoder-1-2739513289 after encoding 1 to 2
2026/03/04 23:12:24.451417 [ENC] Next segment to pre-encode of 3 is 4.506133333s from the last request of 1
I think the key error is:
[h264_vaapi] Failed to map output buffers: 24 (internal encoding error)
This only happens during browser playback. All other transcoding paths work normally.
From what I can tell, this looks like a VAAPI parameter incompatibility between the FFmpeg command used for browser HLS transcoding and the newer Intel iHD driver used by Meteor Lake / Core Ultra GPUs.
Any help getting this resolved to full functionality is greatly appreciated.