Bitrate Question

[DEAD TERMINATOR]

If I am converting a video file from one file format to another can I completely maintain quality if the converted file features the same bitrate? Obviously the filesize might get bigger or smaller. Is there any advantage to raising the bitrate above that of the original source. For example, I have a mkv file at 720p with a bitrate of ~3300 and I want to convert it to DivX. Will I suffer any loss in quality if the DivX output also has a bitrate of 3300? Any advantage to raising it to 3500 or 4000?

[Baldrick]

Yes, you will lose quality. Especially if your mkv uses h264/avc compression that usually has better quality at same bitrate as xvid.

Increasing the bitrate will help a bit. Or use constant quality encoding mode if you don't need an exact output file size.

[DrDeceit]

What is the video format of the original file

[jagabo]

Reencoding with a lossy codec will always give reduced quality, no matter how much bitrate you use. Each encoding will lose some detail and produce some artifacts. The question is how much quality is lost and whether it will be visible on casual viewing. Different codecs (and different settings within those codecs) require different bitrates to maintain watchable quality.

You could answer this yourself with a quick experiment. Take an Xvid video at a particular bitrate and reencode it at the same bitrate. Then take that new file and reencode it again. Repeat for several generations. Compare the first generation to the last.

[DrDeceit]

Reencoding with a lossy codec will always give reduced quality, no matter how much bitrate you use. Each encoding will lose some detail and produce some artifacts. The question is how much quality is lost and whether it will be visible on casual viewing. Different codecs (and different settings within those codecs) require different bitrates to maintain watchable quality.

You could answer this yourself with a quick experiment. Take an Xvid video at a particular bitrate and reencode it at the same bitrate. Then take that new file and reencode it again. Repeat for several generations. Compare the first generation to the last.

^this

But, if encoding from a less advanced format to a more advanced, the quality loss could be 1% even if you use a 2x LOWER bitrate (basically halving the file size retaining quality)

Example: encoding a 1920x1080 40.0 Mbps MPEG2 video to 1920x1080 AVC (H264) at 16.0 Mbps with decent settings

but we have no idea what bitrate to suggest if we dont know the sources format, if its AVC(H264) you might need 2x the bitrate, if its MPEG2 you might need 80%

[DEAD TERMINATOR]

I'm converting mkv files to DivX. I'm interested in playing these files on ps3, so if there is a better format that plays on ps3 I'm open to it.

[poisondeathray]

Depending on what encoding settings were used on the source file, you might just be able to re-wrap it e.g. mkv2mp4

Re-wrapping is very fast, no quality loss. It just swaps the container. PS3 can play AVC/AAC in MP4

Use mediainfo (view=>text), copy & paste the results back here

[Baldrick]

Try mkvtomp4 and see if the mp4 works.

Or stream the mkv with ps3 media server.

[DEAD TERMINATOR]

General
Unique ID : 195146500568997420348704122204236112843 (0x92CFD9516EE30CC396606342956563CB)
Format : Matroska
Format version : Version 2
File size : 1.26 GiB
Duration : 55mn 46s
Overall bit rate : 3 243 Kbps
Encoded date : UTC 2012-10-01 03:08:26
Writing application : mkvmerge v5.8.0 ('No Sleep / Pillow') built on Sep 2 2012 15:37:04
Writing library : libebml v1.2.3 + libmatroska v1.3.0

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 55mn 46s
Bit rate : 2 795 Kbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.126
Stream size : 1.09 GiB (86%)
Writing library : x264 core 128 r2216 198a7ea
Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x113 / me=umh / subme=8 / 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=18 / lookahead_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=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=crf / mbtree=1 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language : English
Default : Yes
Forced : No
Matrix coefficients : BT.709

Audio
ID : 2
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : A_AC3
Duration : 55mn 46s
Bit rate mode : Constant
Bit rate : 384 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 153 MiB (12%)
Default : Yes
Forced : No

[DrDeceit]

Video format is AVC (h264)
Audio format AC3

The PS3 is built to decode both of those, like they said, use MKV to MP4

PM me and I'll tell you what settings to use, so you don't accidentally re-encode the video or audio and lose quality.