The VideoLAN Forums

Status:
- Running VLC on old Pentium-4 1.8 Ghz PC with XP-Pro w/1GB Ram
- Two other apps are running at the same time.
- VLC struggles to playback the video even with just Windows Task Manager open

- Video is MP4 converted from AVI
- Converted files with both Handbrake and dotNetFFMPEG

- Handbrake files are 720x480 29.97 fps & Gspot reports 617kbs

- dotNetFFMPEG files are 640x480 29.97 fps & Gspot reports 1,373bps

The Question: If we want VLC to make smallest demands on CPU - what would be the ideal file format & specs ?

We can convert the original AVI files to any format & specs if we just knew the most efficient for vlc to playback.
Thanks for any help.

Assuming you are encoding to H.264 using x264, then you can use the 'FastDecode' tune setting but be aware that it will produce a file about 20% larger than with optimized settings:
Tools -> Preferences (Show settings=ALL) -> Input/Codecs -> Video codecs -> x264
then at the bottom of the right panel "Tune the setting for a particular type of source or situation" -> set it to FastDecode.

- "Assuming you are encoding to H.264 using x264"

.. I'm using VLC 1.1.9
.. I'm using the VLC default profile Video - H.264 + AAC (MP4)
.. The VLC profile it tells me it is using MP4/MOV Encapsulation and H.264 Codec
.. I don't see any reference to X264

1 - Does VLC come with and use X264 ?
2 - Does this profile use X264?
3 - I see I can download x264 from cnet... should I?

4 - VLC Convert/Save with Profile=Video-H.264+AAC(MP4) produces file with end cut off... how to fix this?
5 - I setup Fast Decode as instructed but is Profile=Video-H.264+AAC(MP4) using it or must I add X264 somehow?

Thanks for the help with this.

MPEG-4 ASP encoder (e.g. Xvid) and decoder might be better option for old computer.

1. Yes.
2. Yes.
3. No. VLC has everything build-in.
4. How much off?
5. It should use it.

Thanks VLC_help! Really appreciate the help!!!

- Using the Default VLC Profile... Video - H.264 + AAC (MP4) ...to convert the original AVI to an MP4 ...cuts off the last 1.621 seconds

- Modifying this profile to Bitrate=800kbs and Scale=0 fixes the problem! (woops! also need to change profile video codec from h264 to mpeg4)

Default VLC Profile:
:sout=#transcode{vcodec=h264,vb=0,scale=0,acodec=mp4a,ab=128,channels=2,samplerate=44100}:file{dst=C:\\Documents and Settings\\All Users\\Documents\\My Videos\\video1OrigProf.mp4} :no-sout-rtp-sap :no-sout-standard-sap :ttl=1 :sout-keep
If this is a short tutorial clip... or whatever... this is not good.

Modified VLC Profile (bitrate=800kbs, scale=1):
:sout=#transcode{vcodec=mp4v,vb=800,scale=1,acodec=mp4a,ab=128,channels=2,samplerate=44100}:file{dst=C:\\Documents and Settings\\All Users\\Documents\\My Videos\\video1mod-1prof.mp4} :no-sout-rtp-sap :no-sout-standard-sap :ttl=1 :sout-keep

If you look at the transcoded output file with Gspot it shows the length difference...

... VLC default profile Video - H.264 + AAC (MP4) - Len=34.899 seconds
... Profile Mod to kbs=800 and scale=1 yeilds Len=36.52 seconds

1 - Any idea why this is occurring?
fyi - It seems setting the bit rate is what does it... (also need to change profile video codec to mpeg4)
... leave bitrate=0 with scale=1 and no workie...
... but bitrate=800kbs and sale=0 works

2 - I've seen other post with this problem. If setting the bitrate is an OK patch/fix I wonder I should post it under it's own header so others can find it easily until the dev team gets around to a better fix?

3 - Finally, the Fast Decode option doesn't help VLC playback on a Pent-4, 1.8Ghz XP-Pro machine with 1GB ram. Still requires 7-%-80% of cpu. For this case we can transcode or render the files to any decent format to get them to run on the Pent-4 machines... else we have to toss a bunch of PC's and wipe out the budget! Transcoding to WMV still demands 70%-80% cpu time to play back... any other format we should consider?

Thanks again for the help.

Correction: Upon further testing even this setup is cutting off the last of converted/transcoded videos.
Example:
Original AVI length = 41.242 seconds
Converted MP4 length = 40.974 seconds

This .268 seconds may not seem like much..
... but when the video is a short tutorial or other narrative...
... cutting off the last word or two is not good.

Anybody have any ideas about how to fix this?

Thanks.

VLC 1.2.0 shouldn't cut that much. But for VLC 1.1.x there isn't any good solution.