December 05, 2020, 03:38:20 pm

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Low framerate during playback with v2.7.6

Started by noisywan, November 21, 2020, 11:34:31 am

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noisywan

Hi folks
I'm having playback issues with Avidemux v2.7.6 on Windows 7 64bit.

The file is a 4K MKV video:
HEVC Main 10@L.5.1
2160p, 24fps, 14M bit/s
DTS 6 chn audio

Video frame rate drops to half speed (~10fps) in Avidemux playback while audio playbacks normal.

Display is in DXVA2 mode
`Decode video using DXVA2` is enabled in HW Accel menu.
`Enable all SIMD` is checked

Same video playbacks fine in VirtualDub2 and MPC-HC

Any suggestions to fix this issue?
Thanks in advance


eumagga0x2a

Please provide admlog.txt (%localappdata%\avidemux\admlog.txt) from loading the file.

A considerable slowdown can originate from copying decoded picture data from the hardware video decoder in the graphics card to the main memory and back to the graphics card for display.

noisywan

Here is the log file.
You cannot see attachments on this board.


eumagga0x2a

A quote from the log:

Probing for DXVA2...
[admD3D_initD3D9Ex] 20:39:31-147 Probing for D3D9EX support
[admD3D_initD3D9Ex] 20:39:31-157 D3D library loaded in D3D9Ex mode, Checking Adapater display mode
[admD3D_initD3D9Ex] 20:39:31-157 Display is 1920 x 1080, fmt=0x16
[admD3D_initD3D9Ex] 20:39:31-157 D3D Device: AMD Radeon HD 5800 Series, Vendor: 1002, Device: 689e, Rev: 0, Driver Version: 2251872828786044
[admD3D_initD3D9Ex] 20:39:31-157 Creating Device9EX
[admD3D_initD3D9Ex] 20:39:31-182 D3D:d3d9Ex core successfully initialized
[admDxva2::init] 20:39:31-182 Dxva2 init step1
[admDxva2::init] 20:39:31-182 Dxva2 core successfully initialized
[admDxva2::init] 20:39:31-182 Decoder service=00000000005495F8
Potential device_guid :
0x1b81be69 0xa0c7 0x11d3  b9  84  00  c0  4f  2e  73  c5
Potential device_guid :
0x1b81be68 0xa0c7 0x11d3  b9  84  00  c0  4f  2e  73  c5
[checkDecoderConfiguration] 20:39:31-183 has h264 raw bistream2
[checkDecoderConfiguration] 20:39:31-183 has no encrypt
[checkDecoderConfiguration] 20:39:31-183 best score
[checkDecoderConfiguration] 20:39:31-183 has h264 raw bistream2
[checkDecoderConfiguration] 20:39:31-183 has no encrypt
[checkDecoderConfiguration] 20:39:31-183 has h264 raw bistream2
[lookupCodec] 20:39:31-183 DXVA2 support for  H264 found
Potential device_guid :
0x5b11d51b 0x2f4c 0x4452  bc  c3  09  f2  a1  16  0c  c0
Potential device_guid :
0x107af0e0 0xef1a 0x4d19  ab  a8  67  a1  63  07  3d  13
[lookupCodec] 20:39:31-183 No decoder device for codec H265 found
Potential device_guid :
0x5b11d51b 0x2f4c 0x4452  bc  c3  09  f2  a1  16  0c  c0
Potential device_guid :
0x107af0e0 0xef1a 0x4d19  ab  a8  67  a1  63  07  3d  13
[lookupCodec] 20:39:31-183 No decoder device for codec H265 found
[admDxva2::init] 20:39:31-183 Scanning supported format done

This graphics card (UVD 2.2) has no decoding support for HEVC (available from UVD 6 on), the CPU is doing all the decoding work. No idea what VirtualDub2 and MPC-HC are doing to achieve real-time decoding. Maybe they are dropping (a lot of) frames.

noisywan

Thank you for the diagnosis. Looks like HEVC without a decent GFX card won't let me edit 4K in Avidemux.

I must correct something that I overlooked about VirtualDub2 previously. It does NOT playback at realtime, but it's close. (about 3/4 speed)

The MPC-HC `feels` like it's realtime, I don't see any drops but I can't be %100 sure about that.