[Fixed] Preset with Constant Quality=100 is not restored.

[rlmcneary2]

Windows 7
Handbrake v0.9.4

If I create a preset with the "Video" setting "Constant Quality" at 100% it is not restored later when the preset is selected. It appears that the log only stores information from the CLI, so I am not including it, however I can attach one if requested.

To reproduce:

1. Open an MTS video source (I'm using an AVCHD Lite file from a Panasonic DMC-ZS3).
2. Select the "Video" tab.
3. From "Presets" select "Regular" - "High Quality" --> "Constant Quality" is set to "60.78% RF:20".
4. Change "Constant Quality to "100% RF:0".
5. Under "Presets" click "Add".
6. Enter a name (I used the very exciting "test") and click "Add"
7. From "Presets" select "Regular" - "High Quality" --> "Constant Quality" is set to "60.78% RF:20".
8. From "Presets" select the new preset --> "Constant Quality" remains set to "60.78% RF:20" when it should have changed to "100% RF:0".

If I set "Constant Quality" to the next lowest available value "99.51% RF:0.25" the value is stored and retrieved successfully.

[Deleted User 11865]

Who cares? Using x264 RF 0 (i.e. 100% quality) is stupid.

[BradleyS]

RF values greater than say, 18, only increase bitrate and provide no humanly visible quality gains. x264 developers have said many times that RF 19.25 is near-transparent to the source for SD content. On HD content, an even lower RF may be necessary.

I have a Panasonic GF1 and I shoot all videos as 720p AVCHD Lite at the highest quality setting. Then, I run them through HandBrake using the High Profile preset at RF 19.25, and trash the originals afterward. The output is roughly one-third of the file size and nearly identical to the source in terms of quality.

How can this be? x264 is awesome.

Cheers.

[BradleyS]

Quick note to add:

Despite the obvious point that using RF 0 is silly, the bug mentioned is probably legit. I'm guessing that there is a comparison against 0 instead of null/nil, causing a value of 0 to be seen as RF not set, instead of set to zero.

+1 for removing % display in the GUI, in favor of sane RF values.

[rlmcneary2]

You certainly are entitled to your opinion, on the other hand it's difficult to anticipate what every user's needs might be. For example the output from Handbrake might only be an intermediate step that will be edited or manipulated in some fashion then resized / recompressed later in a variety of output formats. In such a case wanting a version as close to, or actually lossless doesn't seem to silly to me, but I'm not a video expert.

[Deleted User 11865]

You certainly are entitled to your opinion, on the other hand it's difficult to anticipate what every user's needs might be. For example the output from Handbrake might only be an intermediate step that will be edited or manipulated in some fashion then resized / recompressed later in a variety of output formats. In such a case wanting a version as close to, or actually lossless doesn't seem to silly to me, but I'm not a video expert.

Then HandBrake isn't the tool for you.

[s55]

Fixed - http://trac.handbrake.fr/changeset/3059

[BradleyS]

I'll prefix this with the fact that I previously worked at a video production company, and I do a lot of work with video today. Most of my workflow is uncompressed. All that to say, I don't dispute your need for more bits, and fully know that what looks good to the human eye may not look good to a computer in an editing workflow.

Two things:

1) If your goal is to retain as much quality as possible for future editing, retain the original or consider using another tool. HandBrake and x264 make for a great final step, and while they can be used earlier in your workflow, IMHO there are better solutions out there.

2) RF 0 is still silly. It will probably create files larger than the originals. Rodeo recently mentioned to me that RF 10 is x264's default qpmin (http://mewiki.project357.com/wiki/X264_Settings#qpmin). Adding more bits does not necessarily create better quality noticeable by a human *or* a computer.

As I mentioned before, I use RF 19.25 and this is my personal workflow (read: non-production).The quality when edited and recompressed is more than acceptable to me. For mission-critical work, RF 10 makes some sense, and lower makes little sense at all. I'm basing this on the advice by x264 developers as well as personal verification in a production workflow.

All the best.

[BradleyS]

Nice work s55.

[mduell]

+1 for removing % display in the GUI, in favor of sane RF values.

I proposed in IRC last week the current 0-100%/51-0RF slider should be replaced with the following 5 position slider:
15 I want gigantic output files.
18 Playback on a large screen.
20 Normal
22 Squeeze down an HD source a bit more.
25 I'm kind of starved for space and my playback device is small.

[BradleyS]

IMHO that's a bit too restrictive. However, I would enjoy seeing that in a tooltip for the slider control.