Converting with X-Media Recode

[OrtegaSeason]

Hi there,

I want to a convert an MP4 file to an avi with X-Media Recode and have it be as close to the original quality as possible.

What settings on;

Rate Control Mode and Bitrate should I be using?

Are there any other settings I should be altering from the defaults?


Thanks

[smrpix]

.avi and .mp4 are simply containers. Without knowing what video and audio codecs you're starting with, or how you eventually plan to view them, no one can give any meaningful advice.

Use Mediainfo to find out what's in your mp4. Post the tree view here if you need more help.

[OrtegaSeason]

Here are the specs. Thanks

Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42
File size : 714 MiB
Duration : 1h 33mn
Overall bit rate mode : Variable
Overall bit rate : 1 068 Kbps
Encoded date : UTC 2012-07-10 23:10:59
Tagged date : UTC 2012-07-11 01:47:34
Writing application : HandBrake 0.9.6 2012022800


Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.0
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1h 33mn
Bit rate : 1 000 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 25.000 fps
Minimum frame rate : 6.579 fps
Maximum frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.096
Stream size : 668 MiB (94%)
Writing library : x264 core 120
Encoding settings : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=2pass / mbtree=1 / bitrate=1000 / ratetol=1.0 / qcomp=0.60 / qpmin=3 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2012-07-10 23:10:59
Tagged date : UTC 2012-07-11 01:47:34
Color primaries : BT.601 NTSC
Transfer characteristics : BT.709
Matrix coefficients : BT.601


Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 1h 33mn
Bit rate mode : Variable
Bit rate : 64.2 Kbps
Maximum bit rate : 123 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 42.9 MiB (6%)
Language : English
Encoded date : UTC 2012-07-10 23:10:59
Tagged date : UTC 2012-07-11 01:47:33

[smrpix]

In XMedia Recode .avi essentially means divx. Try a short sample at the default settings. If you don't like the quality, raise the bitrate.

[jagabo]

Foget bitrate. Use Constant Quantizer at 2 or 3. XMediaRecode doesn't let you set the quantizer directly, it uses a "Quality" setting. Set it to 90 or 95, or thereabouts.

[OrtegaSeason]

Foget bitrate. Use Constant Quantizer at 2 or 3. XMediaRecode doesn't let you set the quantizer directly, it uses a "Quality" setting. Set it to 90 or 95, or thereabouts.

Is that a general setting I should use, or is it only for the file I've given the details of?



Thanks

[jagabo]

Foget bitrate. Use Constant Quantizer at 2 or 3. XMediaRecode doesn't let you set the quantizer directly, it uses a "Quality" setting. Set it to 90 or 95, or thereabouts.

Is that a general setting I should use, or is it only for the file I've given the details of?

For all files if you care about quality rather than file size.

[OrtegaSeason]

Foget bitrate. Use Constant Quantizer at 2 or 3. XMediaRecode doesn't let you set the quantizer directly, it uses a "Quality" setting. Set it to 90 or 95, or thereabouts.

Is that a general setting I should use, or is it only for the file I've given the details of?

For all files if you care about quality rather than file size.

This may be a stupid question, but I've noticed that the "quality" setting goes up all the way to 100 but when you use this setting it makes the file quite a bit heavier. Is it actually improving the quality of the file though, if you set it to 100 rather than 90/95?

Thanks

[davexnet]

It may be raising the technical quality, ie. lower (or lowest) quant value.
Whether you can see any difference, that's for you to say.

[jagabo]

Is it actually improving the quality of the file though, if you set it to 100 rather than 90/95?

Yes. If you look at enlarged still frames you'll be able to see a difference.

[OrtegaSeason]

Thanks for the other answers.

If I were to use one of the Bitrates instead of Constant Quantizer, what would be the best settings though?

If I use MediaInfo I can identify what the Maximum bitrate on a file should be. If I set the bitrate to a bit above that should it retain the same quality? Also, would it be better to use constant, average or variable

Basically, these edits I'm doing are for other people's benefit and I just want to make sure I'm converting them as close to the original quality as possible without having to do a close comparison everytime.

Thanks

[hello_hello]

The bitrate of the source video has nothing to do with the bitrate required to re-compress it. It just comes down to how hard the video is to re-compress. And given the goal is AVI I assume you're re-compressing video encoded with the x264 encoder while using an mpeg4 encoder (Xvid/Divx etc) which is older and less efficient.

When you specify a file size (or bitrate) you're effectively specifying the quality without knowing what it'll be. When you specify the quality the unknown becomes the bitrate. As each video will compress differently, the bitrate required for a given quality will change with each encode.

Constant bitrate: The birate is constant so the quality will vary throughout the encode. More bits than necessary here, maybe not enough there etc. Whether it's noticeable will depend on how high the constant bitrate is.

Variable bitrate: The bitrate varies so theoretically the quality remains constant throughout the encode. 2 pass encoding is often used while specifying a target (average) bitrate or a file size. The encoder works out how to distribute the bits during the first pass and encodes during the second. Quality should remain constant throughout but because you're specifying a bitrate you don't know what it'll be.

Average bitrate: It's variable bitrate, so it's less wasteful than constant bitrate and for a given bitate it should provide better quality, or a more consistent quality thought an encode, but it only uses single pass encoding. Without a first pass the encoder has to keep making quality adjustments to hit the target average bitrate by the end of the encode.... ie it kind of guesses as it encodes.

Constant Quantizer: Not exactly a true quality based encoding method but fairly close. Many encoder GUI's refer to it as a quality setting. It's a single pass encoding method using a variable bitrate. The file size/bitrate is unknown.

Constant Ratefactor: (x264 encoding only, as far as I know) It's a quality based, single pass encoding method which uses a variable bitrate. The normal rule applies. You can specify the quality, but the bitrate required for a particular quality will vary with each encode. Around CRF18 the x264 encoder is considered to be "transparent". Higher CRF values = lower quality = smaller file size.

For "as close to the original quality as possible" when re-encoding and outputting AVI (Xvid encoding etc), a constant quantizer of 2, which is often referred to as 100% constant quality by encoder GUIs, is about as good as it gets. How much can you reduce the quality before you'll notice it drop...... probably by at least 20% when watching the video in a normal manner. If you compare 100% and 80% quality frame by frame you can see a difference though.