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16th October 2011, 06:46 | #1 | Link | |
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Join Date: Feb 2002
Location: Chicago, IL
Posts: 496
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Blu-Ray - BD50 bitrates overkill?
In doing some backups to BD25, I am noticing more and more releases from Studios on BD50 even for movies where its probably not necessary. Take for instance Airplane - this is only an 88min movie, with no bonus video features. This should surely fit on a BD25 even with the DTS-MA audio.
My practice for many titles is to just use the core from DTS-MA, but now I am just deciding to keep the DTS-MA if the movie is 125min or less as I think studios are just using BD50 even if its not needed. So why are studios doing this? I would assume they are maxing out the bitrate on the video since they have the space. Perhaps this makes for cheaper production costs as they do not need to QA the film as much knowing its maxed out bitrate. Or is it to prevent easy movie backups since BD50 media is still expensive? Found this forum post on dvdtown, so I ask are latest BD50 bitrates overkill? Quote:
What are the guidelines or best practice others use here for backups to BD25? P.S. The new blank feature and ability to create bonus only BD5/9 discs is working perfect so far. Anf I don't think I have seen many posts here either with anyone reporting any issues. Then again, I am about to do Drumline which has many extra streams for branched play. Here is an example comparison (these are both with DTS-MA): Disc Title: RED_DRAGON R1 (BD-Rebuilder) Disc Size: 23,441,105,049 bytes Protection: AACS BD-Java: Yes Playlist: 00000.MPLS Size: 21,650,042,880 bytes Length: 2:04:33 Total Bitrate: 23.17 Mbps Video: MPEG-4 AVC Video / 17685 kbps / 1080p / 23.976 fps / 16:9 / High Profile 4.1 <---- So even with a recode and keep HD Audio for 125min movie, its still above 16 kbps Audio: English / DTS-HD Master Audio / 5.1 / 48 kHz / 4203 kbps / 24-bit (DTS Core: 5.1 / 48 kHz / 1509 kbps / 24-bit) Subtitle: English / 37.774 kbps Disc Title: RED_DRAGON R1 (ORIGINAL) Disc Size: 46,040,122,027 bytes Protection: AACS BD-Java: Yes Playlist: 00000.MPLS Size: 38,158,301,184 bytes Length: 2:04:33 Total Bitrate: 40.85 Mbps Video: MPEG-4 AVC Video / 32409 kbps / 1080p / 23.976 fps / 16:9 / High Profile 4.1 Audio: English / DTS-HD Master Audio / 5.1 / 48 kHz / 4203 kbps / 24-bit (DTS Core: 5.1 / 48 kHz / 1509 kbps / 24-bit) Last edited by jfcarbel; 18th October 2011 at 02:21. |
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19th October 2011, 06:09 | #2 | Link | |
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@jfcarbel
Hi! Quote:
It's my opinion that the studios unnecessarily "swell up"/pad the bitrate to try to convince the consumer that he/she is getting something "really special" by purchasing Blu-rays, rather than continuing to purchase DVDs and play them on a good upconverting standalone player ;>} |
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19th October 2011, 06:29 | #3 | Link |
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Join Date: Nov 2001
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To combat upscaling they actually lower bitrates on DVDs. Back in the day I'd always need Shrink to make a movie fit on a single-layer blank. These days even 2 hour movies are often < 4 GB.
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19th October 2011, 09:44 | #4 | Link | |
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Join Date: Mar 2009
Location: Germany
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Quote:
H.264 is quite powerful in terms of achieved quality at a specific bitrate. BD DL are probably used more as a copyright control (a BD-RE 50GB costs in Germany, through official channels, more than a regular original BD, a BD-R 50 almost the same) than as a technical requirement. However, it happened to MP3 and then to DVD/DivX, so it will probably happen to BD too: the longer the people are "exposed" to higher quality material (and get used to), the better they will notice the artefacts (more objectionable), and the more they will increase the bitrate to compensate for it. The "correct" bitrate is the one you consider to be, taking into account your quality expectations, your viewing capacities, your experience, and your budget. Quality is personal.
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23rd October 2011, 10:03 | #7 | Link |
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Join Date: May 2006
Posts: 3,997
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I do most of my backups to BD5: Movie only 720p + 2 audio ac3 448. The viewing quality (viewing, not overanalyzing) from normal distance on LCD TV and on LCD projector is very good IMHO.
Even downscaling to 720p does in most cases not really or noticeably loose details, and applying a slight sharpening like sharpen(0.15) to the downscaled 720p (before encoding) can bring it very close the original viewing experience. (http://forum.doom9.org/showthread.ph...57#post1497357) Last edited by Sharc; 23rd October 2011 at 10:13. |
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