evilclive
18th July 2006, 18:57
I have a large number of films recorded off Freeview, that I want to convert to MPEG-4 to save hard disk space.
I'll be putting the films on a RAID of hard disks whose capacity is measured in terabytes, so the usual issue of getting the files to fit nicely on a CDR or DVDR doesn't apply.
The flagship Freeview channels (BBC1, BBC2 and a few others) are transmitted at about two gigabytes per hour: this compares with 8 megabits per second (3.6 gigabytes per hour) for an average DVD.
The less important Freeview channels are transmitted at about 1GB/hour, and the MPEG-2 artifacts are visible on a decent LCD TV at 25 metres. Yuk!
Back in the old days of DivX 5, the forum consensus was that 0.36 bits per pixel per frame was a perfectly workable bit rate for medium-quality MPEG-4 files (e.g. transcodes from SVCD).
I'll be running the transcode as a batch process, so once I've picked XVid settings that work for one file, I'll reuse them for all of them without further intervention.
Should I be aiming for a specific bit rate per pixel per frame, or would it be better to experiment with the presets (1 to 31, as described in the FAQ)?
I'm trying to save a few TB of hard disk space, without compromising the recording quality "noticeably" (however I'm supposed to determine or guess at that). Approximately what file size (GB/hour) is generally reckoned to be appropriate with the latest codecs, or is the answer to that question impossibly subjective?
I'll be putting the films on a RAID of hard disks whose capacity is measured in terabytes, so the usual issue of getting the files to fit nicely on a CDR or DVDR doesn't apply.
The flagship Freeview channels (BBC1, BBC2 and a few others) are transmitted at about two gigabytes per hour: this compares with 8 megabits per second (3.6 gigabytes per hour) for an average DVD.
The less important Freeview channels are transmitted at about 1GB/hour, and the MPEG-2 artifacts are visible on a decent LCD TV at 25 metres. Yuk!
Back in the old days of DivX 5, the forum consensus was that 0.36 bits per pixel per frame was a perfectly workable bit rate for medium-quality MPEG-4 files (e.g. transcodes from SVCD).
I'll be running the transcode as a batch process, so once I've picked XVid settings that work for one file, I'll reuse them for all of them without further intervention.
Should I be aiming for a specific bit rate per pixel per frame, or would it be better to experiment with the presets (1 to 31, as described in the FAQ)?
I'm trying to save a few TB of hard disk space, without compromising the recording quality "noticeably" (however I'm supposed to determine or guess at that). Approximately what file size (GB/hour) is generally reckoned to be appropriate with the latest codecs, or is the answer to that question impossibly subjective?