Converting HD Videos without noticable quality loss

[zammil]

Hello friends,

I have got many HD films(H.264 & AAC) ranging from 3-6 GB but they are consuming all my disk space. I have seen compressed HD videos with small sizes and unnoticeable quality loss .so i am assuming that i can convert my films without much quality loss.i want them to be re-encoded to 2 GB (1.5 GB video and .5 GB audio).searched on goggle about this but seems pretty much confusing since there are many software & encoding methods to do this .so i request the video experts to suggest which software ,encoding method should i use to yield the output which can save my time and quality.

Thanks in advance

[kypec]

You have to post MediaInfo details of your original files so that we know what are you dealing with. Though, IMHO what you're trying to achieve is pretty dumb.
When your original movie occupies 3-6 GB there isn't good chance it can be squeezed any more without hurting overall quality (video & audio) greatly.
Average HD movie (2 hours) in 720p i.e. resolution = 1280x720 requires at least 4 Mbps video bitrate for decent visual quality.
4000 kb/s * 7200 s = 3433 MB and there is even no audio stream included. If you don't downscale the resolution significantly then the whole encode
will look awful at ~ 2000 kb/s :( Of course, once downscaled, it won't be HD anymore, obviously.

[zammil]

thanks for Ur reply kypec but i I'm afraid i cannot agree with your comment.you can get a decent visual display with 1000 kbps if u r using x264 encoders

http://mirror05.x264.nl/Dark/website/compare.html

[Blue_MiSfit]

It all depends on the content, settings / filtering used, and your definition of "decent visuals" :)

Also, I believe those samples were done at SD resolutions, not at 720p.

In my experience, most content (except really compressible stuff like Big Buck Bunny) looks pretty rough under 2-3mbps for 720p; to the extent that further scaling is really a good idea - i.e. maybe 960x540 instead of 1280x720. Even using x264 and fairly slow settings, it's sometimes tough to deliver that much compression.

In any case, we need more info to give honest advice. Can you post some mediainfo dumps for us?

Thanks,
Derek

[zammil]

This is the media info of video i want to reduce to .The video stream is about 3 GB alone i want to reduce it to 1.5 GB

General
Complete name : E:\The Rock (1996) 720p BDRip .mkv
Format : Matroska
File size : 3.61 GiB
Duration : 2h 16mn
Overall bit rate : 3 789 Kbps
Movie name : The.Rock.1996.720p.BDRip.
Encoded date : UTC 2010-04-22 19:42:47
Writing application : mkvmerge v2.9.8 ('C'est le bon') built on Aug 13 2009 12:49:06
Writing library : libebml v0.7.7 + libmatroska v0.8.1
Cover : Yes / Yes / Yes

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Format settings, GOP : M=1, N=2
Codec ID : V_MPEG4/ISO/AVC
Duration : 2h 16mn
Bit rate : 3 074 Kbps
Width : 1 280 pixels
Height : 544 pixels
Display aspect ratio : 2.35:1
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.184
Stream size : 2.93 GiB (81%)
Writing library : x264 core 93 r1538 bd72d46
Encoding settings : cabac=1 / ref=5 / deblock=1:-3:-3 / analyse=0x3:0x113 / me=umh / subme=8 / psy=1

/ psy_rd=1.00:0.00 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=2 / deadzone=21,11 /

fast_pskip=0 / chroma_qp_offset=-2 / threads=6 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 /

constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / wpredb=1 / wpredp=2 / keyint=250

/ keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=22.2 / qcomp=0.60 /

qpmin=10 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

Audio
ID : 2
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Codec ID : A_AC3
Duration : 2h 16mn
Bit rate mode : Constant
Bit rate : 640 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 625 MiB (17%)
Language : English

My question is can i reduce it to 1.5 GB without taking a quality hit.if not to which size can i reduce it considering quality.if possible tell the s/w tool and encoding settings also which optimizes the quality and time consumed for encoding.i think it is possible because i have seen BDrips of 800-2 GB of stunning quality.hope i will get help from you guys

Thanks in advance.

[SuLyMaN]

General
Complete name : E:\The Rock (1996) 720p BDRip .mkv
Format : Matroska
File size : 3.61 GiB
Duration : 2h 16mn
Overall bit rate : 3 789 Kbps
Movie name : The.Rock.1996.720p.BDRip.
Encoded date : UTC 2010-04-22 19:42:47
Writing application : mkvmerge v2.9.8 ('C'est le bon') built on Aug 13 2009 12:49:06
Writing library : libebml v0.7.7 + libmatroska v0.8.1



No use thanking anybody. Imo this is illegally downloaded film and this forum does not cater for this.