#AC3 448 KBPS FULL#
But the actual bitrate of “1536 Kbps DTS” is 1509.75 Kbps, and that requires only 2012 bytes. I dont agree with you, 448kbps is MINIMUM for AC3 5.1 (this means not even 96kbps per channel), because only starting from that bitrate you get full bandwidth up to 20KHz, and that is equivalent to CD quality.
When dissolve transitions are used, the output profile dialog says that an audio recode is required and the AC3 bitrate is reduced. When jump cuts are used, output specs match input. Q: So how does DTS get away with it with 1536kbps streams?Ī: A DTS audio frame has 1/3 the number of samples as AC3 (and 1/3 the duration), which would imply that 1536 take up the same space as a 512 AC3. Input file is TS, H.264 20 Mbps, AC3 5.1 448 Kbps. 512K frames are 2048 bytes, 576K frames are 2304 bytes, and 640K frames are 2560 bytes. Is this true? Is 640kbps considered out of spec, or just considered not proven to work reliably?Ī: Bitrates of 512K and higher present problems to some multiplexers and players because the size of the audio frame exceeds the payload size of one DVD pack (2025 bytes). Q: I keep reading in DVD guides that the bitrate of AC3 audio on DVDs is limited to 448kbps, even though the maximum bitrate for 5.1 AC3 is 640kbps. That just does not sound right at all when you consider that in the test results on. When I use Q0.35 like you recommend I estimate that the file would be AAC-LC at 345 Kbps and 340 MB and that is just too close to the AC3 at 413 MB size making re-coding worthless. How to Upload/View/Download Images & Attachments : LinkBack: Thread Tools 1 11-10-2003, 12:45 PM Critter. When I use Q0.2 on the Fifth Element AC3 448 Kbps audio track I get AAC-HE at 164 Kbps in VBR at 152 MB and 2.7x size decrease.
#AC3 448 KBPS HOW TO#
If it actually is superior my feeling is that it is so by such a slim margin that most people could never actually tell the difference between it and another good codec in a blind test. Headac3he: Downsample AC3 448 Kbps to 384kbps User Name: Remember Me Password: Ask Question: FAQ : Search: Todays Posts: Mark Forums Read : How to Support I can tell you that my personal opinion is that it’s a fine codec but I remain skeptical that it is superior to others. AAC, also called as Advanced Audio Coding, is a lossy audio format defined by the MPEG-4 standard. Besides, it is used for films at 640 kbps. AAC has its supporters, some of whom are Apple fanboys. AC3 is widely used in the laser disc and DVD limited between 384 kbps and 448 kbps. I personally find AAC cumbersome to deal with as it is not valid for DVD or BluRay audio. Whether it is better than AC3 or not is certainly debatable but given that it is a lossy format converting from AC3 to AAC is going to entail some loss of quality, even if you can’t perceive it.
#AC3 448 KBPS MOVIE#
The fact that AAC supports multiple channels is just a bonus but it really was designed for uses like iTunes rather than as a movie soundtrack.ĪAC is lossy as is AC3. AAC was really designed to replace MP3 rather than to replace AC3. “ If AAC is a superior format comparing to AC3?“
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