0000484: H265 encodes: Difficult to control framerate of result

ID	Project	Category	View Status	Date Submitted	Last Update

0000484	Cinelerra-GG	[All Projects] Feature	public	2020-08-02 05:24	2022-01-22 17:44

Reporter	quintao	Assigned To	PhyllisSmith
Priority	normal	Severity	minor	Reproducibility	random
Status	closed	Resolution	no change required
Platform	Ryzen 3700x	OS	Linux	OS Version	Devuan Beowulf
Product Version	2020-04
Target Version		Fixed in Version

Summary	0000484: H265 encodes: Difficult to control framerate of result
Description	I have been trying some encodes with H265 (ffmpeg), utilising the hi, med and lo options. Results (of a 1 minute video) hi - 44.2 Mbps med - 4.34 Mbps lo - 1.5 Mbps The video quality with 'lo' was really good, but when I tried h265lo on another project (source clips from same camera) the resulting frame-rate was increased to 8.701 Mbps, and the following test, 5.448Mbps, and then again 5.367Mbps. I can't reproduce the 1500 Kbps with the 2nd project - and entering 150000 in the bitrate field does nothing to affect the output. 8, or 5 or 4 Mbps is not really low and it doesn't create small file sizes. To me this is confusing. I want control of the bitrate in the output. Actually I had similar confusing results with ffmpeg/ogg where setting the quality resulted in different bitrates each time, there was no standard output.
Steps To Reproduce	Add clips to project Render settings : ffmpeg/mp4, h265-lo, 1500000 bps Render project check frame rate
Tags	h265, render

PhyllisSmith 2022-01-21 23:44 manager ~0005239	Clarified in the previous note and added a note in the manual to be sure to not set any quality parameters or they will take precedence over bitrate.

PhyllisSmith 2022-01-20 01:32 manager ~0005235	About: "To me this is confusing. I want control of the bitrate in the output." You can definitely control the bitrate you want but you have to make sure that it does not conflict with other parameters that are set. To do this in the Render menu, you have to keyin the desired bitrate in the Bitrate box in the Video wrench menu. The confusion of why it does not seem to be controllable is because if a "crf" value or other parameter is specified that conflicts with the user's requested bitrate, that bitrate could be ignored if the other parameter takes precedence. So if using h265-lo, h265-med, or h265-hi render formats, you should be sure to delete the "crf" parameter in the list box at the bottom of the Video wrench menu and then you will get the bitrate you requested (or very close to it).

Date Modified	Username	Field	Change
2020-08-02 05:24	quintao	New Issue
2020-08-02 05:24	quintao	Tag Attached: h265
2020-08-02 05:24	quintao	Tag Attached: render
2022-01-20 01:32	PhyllisSmith	Assigned To	=> PhyllisSmith
2022-01-20 01:32	PhyllisSmith	Status	new => acknowledged
2022-01-20 01:32	PhyllisSmith	Note Added: 0005235
2022-01-21 23:44	PhyllisSmith	Status	acknowledged => resolved
2022-01-21 23:44	PhyllisSmith	Resolution	open => no change required
2022-01-21 23:44	PhyllisSmith	Note Added: 0005239
2022-01-22 17:44	PhyllisSmith	Status	resolved => closed