What size difference bw AC3 and mp3?

[lilhobo]

what s the size difference between AC3/2 or C3/6 compared to mp3 192kps?

Anyone got some rough guides?

for sizes 1.4Gb and under

[Inspector.Gadget]

Google "bit rate".

[lilhobo]

omg just say if its 100-200 mb difference

[Inspector.Gadget]

Nobody can tell you that - it depends on bit rate and the length of the movie. In other words, it depends on the file size of the audio as it exists un-muxed. You have nearly 400 posts and you're reduced to "omg" because you asked an unanswerable question , didn't think to use search, and didn't bother to read up on basic concepts? You can save yourself a lot of time with a few minutes of research on introductory subjects.

[Groucho2004]

omg just say if its 100-200 mb difference

142 mb.

Edit: Sorry, couldn't resist.

[Lyle_JP]

First lilhobo, you must answer these three questions:
Which is bigger, a 14MB file with 10 minutes of music, or a 14 MB file with 20 minutes of music?
What takes longer: Boiling one 3-minute egg or three 3-minute eggs?
If someone bought 3 one-dozen packs of stamps with a face value of 4 cents each, how many stamps does he have?

Answers: 14 MB is 14 MB regardless, 3 minutes (all the eggs cook in one pot), and I already told you he had 3 dozen stamps!
My point? Don't ask us trick questions. Bitrate is bitrate, period. If an mp3 file is 320kbps, and an ac3 file is 320kbps, then if they're both the same length they will both be the same size. And if you have an ac3 track at 448kbps and an mp3 track at 224kbps, again the same length, then the mp3 file will be... (drumroll, please) half the size. Cause, you know, it's like half the bitrate, or something.

So yes, we've had a little fun at your expense, but when you ask a forum of people to do 4th grade arithmetic for you (and that's all calculating bitrate is, simple math), then this is what can happen.

[Ghitulescu]

for sizes 1.4Gb and under

First lilhobo, you must answer these three questions:
Which is bigger, a 14MB file with 10 minutes of music, or a 14 MB file with 20 minutes of music?
What takes longer: Boiling one 3-minute egg or three 3-minute eggs?
If someone bought 3 one-dozen packs of stamps with a face value of 4 cents each, how many stamps does he have? The answers are valid only for eggs weighting 35 grams or less. :p

So yes, we've had a little fun at your expense, but when you ask a forum of people to do 4th grade arithmetic for you (and that's all calculating bitrate is, simple math), then this is what can happen.:p

[nibus]

In general AC3 tracks from DVD's are going to be much larger because they are usually 6 channels, equaling a bitrate of around 448kbps. IF you were to convert this to Mp3 at 192kbps, the file size would be much smaller because 192kbps < 448kbps. However if you are asking which codec is larger at the same bitrate, of course they are the same. Kbps = actual kilobits per second of space that is used. Higher bitrate = larger file. Most stereo AC3 tracks from DVD's are already 192kbps, so there really wouldn't be a point in converting them to mp3 unless you HAD to have it in mp3 for compatibility.

I'm not sure if that's what you are asking... your question isn't very clear.

[dilpill]

I'll try to make this easy for you.

Say you have a AC3 file for a two hour movie that you are trying to convert into a 700 MB backup. The source AC3 file has a bitrate of 448 kbit/s, and therefore a filesize of about 403,200 KB.

448/8*120*60
(bitrate)/(bits per byte)*(length in minutes)*(seconds per minute)

To save space for your 700 MB rip, you want to compress the audio to the MP3 format. You choose a bitrate of 128 kbit/s because it has a good balance between quality and filesize. This MP3 file would have a filesize of about 115,200 KB.

128/8*120*60

In this scenario, converting the AC3 audio to MP3 saved you 288 000 KB, or ~71%. It all comes down to the bitrate difference. You can quickly calculate the percentage saved by dividing the new bitrate by the original bitrate and subtracting that from one.

1-115200/403200=1-128/448=~71%

Of course, this space saving isn't free; the conversion from AC3 reduces the number of channels from 6 to 2 and introduces some artifacts.

[Lyle_JP]

Kbps = actual kilobytes per second of space that is used.

Actually, kbps stands for kilobits per second, IIRC.

[lilhobo]

how do you check for the bitrate of the AC3 in a DVD? does vlan player tell you?

so standard AC3/2 is same quality and size as mp3 at same bitrate?

[nibus]

Actually, kbps stands for kilobits per second, IIRC.

fix'd

how do you check for the bitrate of the AC3 in a DVD? does vlan player tell you?


In VLC go to Tools > Codec Information. It will list the codecs name and bitrate. AC3 is usually listed as A52.

In MPC go to File > Properties.


so standard AC3/2 is same quality and size as mp3 at same bitrate?

It is very close. I would probably lean toward AC3 but that's just me.

This might help:
http://forum.doom9.org/showthread.php?t=22250

If you are wanting to save space I would suggest using Nero AAC. It is much more efficient than both AC3 and MP3. It also does multi-channel.

[lilhobo]

i need it to play in a 2.5" HDD media player, so AAC may be out.

anyone know what codecs played by the "chinese" made media players?

http://melbourne.gumtree.com.au/c-Stuff-for-Sale-computers-software-components-2-5-USB-Portable-Hard-Disk-Media-Player-80Gb-Brand-New-BOX-W0QQAdIdZ210105849

[Lyle_JP]

i need it to play in a 2.5" HDD media player, so AAC may be out.

anyone know what codecs played by the "chinese" made media players?

http://melbourne.gumtree.com.au/c-Stuff-for-Sale-computers-software-components-2-5-USB-Portable-Hard-Disk-Media-Player-80Gb-Brand-New-BOX-W0QQAdIdZ210105849

Any device which supports the .mp4 container should decode some flavor of AAC, since it's the only "legal" sound format for that container. Anything else is labeled a "private stream".
Edit: After looking at the device linked, it looks like it's not really an mp4 player at all. It's an ASP player, and seems restricted to AVIs with divx/xvid based video and mp3 sound.

And while mp3 and ac3 are pretty similar in their compression qualities (ac3 has a slight edge), aac is noticeably more efficient. In my experience, for stereo sound 192k ac3 = 192k mp3 = 160k or 128k aac (depending on complexity). For multichannel, 384k ac3 = 256k aac, 448k ac3 = 320k aac, and aac at 384k is nearly transparent to whatever source you choose to feed it. I left multichannel mp3 out of the comparison since almost no devices support it and I've no experience with it.

[nurbs]

Any device which supports the .mp4 container should decode some flavor of AAC, since it's the only "legal" sound format for that container. Anything else is labeled a "private stream".
MP3, possibly other MPEG audio formats and recently AC3 (IIRC) are supported as native streams as well. Most mp4 players will likely play AAC, but that's not the only "legal" option when it comes to audio.

[dilpill]

It is very close. I would probably lean toward AC3 but that's just me.
At the same bitrates? No way. Stereo AC3 at 128 kbit/s sounds horrible compared to MP3 and AAC.

From a quality standpoint, the only reason to go with AC3 is to keep the original unprocessed stream from whatever source you have. AAC is much more efficient and should be used in all applications in which transcoding is required and there aren't any other restricting factors.

[Lyle_JP]

At the same bitrates? No way. Stereo AC3 at 128 kbit/s sounds horrible compared to MP3 and AAC.

But that trend seems to reverse itself at higher bitrates. I find 192k ac3 a hair more pleasing than 192k mp3.

[nibus]

At the same bitrates? No way. Stereo AC3 at 128 kbit/s sounds horrible compared to MP3 and AAC.

From a quality standpoint, the only reason to go with AC3 is to keep the original unprocessed stream from whatever source you have. AAC is much more efficient and should be used in all applications in which transcoding is required and there aren't any other restricting factors.

Both AC3 and Mp3 sound bad at 128k. At 192k, which is what the OP was questioning, AC3 sounds better to me than mp3 at the same bitrate.

[Ghitulescu]

Both AC3 and Mp3 sound bad at 128k.

I am old enough to remember the first days of MP3. Then the motto was: "128kbps MP3 is undistinguishable from the original CD". Now people start to find out that 128kbps is bad even for movie sounds. That' s a good trend :p

[Forteen88]

I am old enough to remember the first days of MP3. Then the motto was: "128kbps MP3 is undistinguishable from the original CD". Now people start to find out that 128kbps is bad even for movie sounds. That' s a good trend :pAnd in those days the MP3-codecs were very bad compared to nowadays LAME.