[FEAT] scale granularity of filesize slider in manual mode

[deutrino]

Feature Request

I tend to use the manual mode instead of presets because that's just how I roll, because my videos are different lengths and I like to choose a specific size based on length rather than always shoot for 10 or 25 megs, because I prefer lower resolution with higher quality to higher resolution with visible artifacts and thus I want 480p instead of 720p, etc.

In most cases I'm recompressing short videos to send via instant messaging so I am looking to get fairly small output files.

I'll illustrate with the case which led to me submitting this issue.

I have a ~240MB 1080p video of about 1 min 40 sec which I want to resize to 480p and compress to H.264 somewhere about 10 megs in size.

Current Behaviour

1. The file size slider minimum is 12MB, which IMO should be lower for a video of 1 min 40 sec at a resolution of 480p, even with H.264.
2. Selecting 12MB actually outputs a video of 20MB. This may or may not be relevant (or a bug) since my device may have something to do with it?
3. It might be nice for the slider to have more granular 'ticks' at the small end, currently it goes from 12MB to the size of the original video (~240MB) in 1MB steps. Transitioning to 0.5MB steps close to the lower end might be nice ... and also there are a huge number of ticks and thus a degree of granularity that probably isn't needed in the middle to upper end of the requested size range, because if somebody wants a filesize near the top of the range (presumably due to wanting high quality) they are not gonna care about 232MB vs 236MB vs 240MB.

Device Info

App: Compressor v1.6.0
Device: Xiaomi POCO F1 (Android 12)
Chipset: Qualcomm SDM845
RAM: 5.5 GB
GPU: Adreno (TM) 630
Device-specific Workaround: None
Supported Encoders: video/avc, video/hevc

Disclaimer

• I have read [READ FIRST] Features/bugfixes that will NOT be implemented #3 and my issue is not listed there
• I am adding a valid title to my issue

[JoshAtticus]

Hi @deutrino, thanks for opening an issue! I have a few responses to your points in current behaviour:

1. The minimum target size is an educated guess on around how small the video can become based on its resolution, framerate, length, bitrate and audio bitrate. Furthermore, you have mixed up H.264 and H.265, H.265 produces 40-50% smaller files while retaining the same picture quality as H.264.
2. This is either caused by your device, or the video is simply too long to compress down to a small enough bitrate for 12MB while retaining any usable pixels (software compressors like ffmpeg solve this but are much slower and more inefficient)
3. I'll look into this. I did try fixing it with an earlier commit, but I see what your issue is and I am able to reproduce it.