Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. |
29th February 2012, 23:04 | #21 | Link | |
(schein)heilig
Join Date: Jun 2003
Location: Germany
Posts: 512
|
Quote:
__________________
Brother John When lost in BeSweet's options, have a look at the Commandline Reference. DVD nach MPEG-4 klappt nicht? Verzweifelt? Auf zum Encodingwissen! |
|
6th March 2012, 16:18 | #22 | Link |
Registered User
Join Date: Jan 2012
Posts: 20
|
Thanks everyone for their replies. Now I can finally encode my pictures (TIF) to a smaller size with good quality. However, using the default command line I can only encode each picture at once (if I need to compress 5 pics, I would need to encode all 5 of them individually).
Is there a way where I can encode them (say 5 or 10 pics at the input) simultaneously so that the output will also be in the form continuous pictures (video in mkv for example)? |
9th March 2012, 10:11 | #24 | Link |
Registered User
Join Date: Jan 2012
Posts: 20
|
Thanks nm for the guide. You helped me a lot. I would like to compare the effectiveness of the in-built deblocking filter of x264. I have done a few readings where there are these alpha (strength) and beta (threshold) parameters. I tried encoding a set of frames with the filter turned-on (default) and turned-off (--no-deblock) and hardly notice any difference.
If I want to disable the deblocking filter (other than using the command line), can I erase them in the source code (e.g x264.c and encoder.c)? Thank you. |
9th March 2012, 13:52 | #25 | Link | |||
Registered User
Join Date: Mar 2005
Location: Finland
Posts: 2,641
|
Quote:
Quote:
Quote:
Note that in-loop deblocking is mainly supposed to reduce blocking that is produced during encoding, not blocking that is in the source video! x264 automatically lowers deblocking strength when low quantizers (high bitrate) are used for encoding. You can remove most of the deblocking code, which is also spread around a few other files. Or you could just leave it there and add your own code paths where needed. |
|||
11th March 2012, 12:04 | #26 | Link |
Registered User
Join Date: Mar 2012
Posts: 6
|
HI
i try to compile x264 in ubuntu 10.04 and followed the steps given in this website http://ubuntuforums.org/showpost.php...postcount=1289 but in step 7 command ( ./configure --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb \ --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libvpx \ --enable-libx264 --enable-nonfree --enable-version3 --enable-x11grab ) gives following error if you think configure made a mistake, make sure you are using the latest version from Git. If the latest version fails, report the problem to the ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net. Include the log file "config.log" produced by configure as this will help solving the problem. please tell me how i can resolve this . |
11th March 2012, 14:52 | #27 | Link |
Registered User
Join Date: May 2006
Posts: 957
|
ARGH! Can you not read? You didn't even tell us which of the dozen options you used caused the error.
__________________
x264 log explained || x264 deblocking how-to preset -> tune -> user set options -> fast first pass -> profile -> level Doom10 - Of course it's better, it's one more. |
12th March 2012, 16:05 | #28 | Link |
Registered User
Join Date: Jan 2012
Posts: 20
|
I tried encoding the input at even higher crf values (up to 50) for both with and without the deblocking filter. The video quality obviously degrades in both cases but still, I cant spot the difference between the two ouputs. Can this be due to the fact that I only encode around 65 frames (roughly around 2 seconds) which is too short to observe the difference?
I actually have to compare the usefulness of the current deblocking filter in x264 in term of coding time vs quality tradeoff. Also, I have another deblocking filter called the "Edge Adaptive Deblocking Filter" which was previously employed in MPEG-2 standard and I'm required to put this filter to x264 but the source code of x264 is very complicated. Can this be achievable actually? |
12th March 2012, 17:28 | #29 | Link | ||
Registered User
Join Date: Mar 2005
Location: Finland
Posts: 2,641
|
Quote:
CRF 40, default settings: bbb_crf40_deblock.mp4 CRF 40, --no-deblock: bbb_crf40_nodeblock.mp4 Quote:
If it's just a pre-/postprocessing filter, it would be pretty simple to add it to the input filtering system of x264. But comparing that to in-loop H.264 deblocking is apples to oranges. You need to put the filter to the decoding side, not x264. Last edited by nm; 12th March 2012 at 17:41. |
||
18th March 2012, 15:21 | #30 | Link |
Registered User
Join Date: Jan 2012
Posts: 20
|
This time I tried coding using another raw video in YUV format as my input file with the following command:
x264 --crf 23 --input-res 352x288 --fps 30 -o ~/Output/out.mkv ~/Input/soccer.yuv However the output file's quality is terrible with some objects in the video missing intermittently. Is there something wrong with my command here? If I'm to modify the deblocking filter, does that mean I have to tweak the decoder too (VLC player in this case?). Also, which .c file is actually the main file (x264.c or encoder.c) because I'm still trying to locate the portion of code where the deblocking filter is used. |
18th March 2012, 15:27 | #31 | Link | |||
Software Developer
Join Date: Jun 2005
Location: Last House on Slunk Street
Posts: 13,248
|
Quote:
So what you are seeing is probably a problem with reading the input file or with decoding the compressed H.264 video later. Quote:
If you "modify" the standard, i.e. you make your own "non-standard" H.264 extension/modification, the decoder would have to be modified accordingly. Quote:
libx264 is the actual x264 encoder library, which is used by the CLI front-end but can also be used by other apps directly. Probably encoder.c is the "main" file of the library. However all applications that call the x264 encoder library only use the functions declared in x264.h, the "public" API. All the rest is considered "private" (internal). Consequently you will find that the front-end (x264.c) will call into the encoder library (encoder.c) first, from where other internal functions at various places will be called... (For the deblocking filter, you will have to look at deblock.c and especially at deblock-a.asm. Maybe the H.264 specifications will help too!)
__________________
Go to https://standforukraine.com/ to find legitimate Ukrainian Charities 🇺🇦✊ Last edited by LoRd_MuldeR; 19th March 2012 at 00:22. |
|||
18th March 2012, 15:48 | #32 | Link | |
Registered User
Join Date: Mar 2005
Location: Finland
Posts: 2,641
|
Quote:
I'd suggest reading a bit more about how H.264 in-loop deblocking is supposed to work before going to the code. There are some nice books about H.264 to start with, but you'll also need to read parts of the ITU-T H.264 recommendation. |
|
19th March 2012, 16:11 | #33 | Link | |
Registered User
Join Date: Jan 2012
Posts: 20
|
Quote:
It looks something like this Anyone knows what is the problem? |
|
19th March 2012, 16:49 | #34 | Link | |
Registered User
Join Date: Mar 2005
Location: Finland
Posts: 2,641
|
Quote:
Code:
vlc --demux rawvideo --rawvid-width 352 --rawvid-height 288 --rawvid-chroma=I420 --rawvid-fps 30 SOCCER_352x288_30_orig_02.yuv |
|
19th March 2012, 19:37 | #35 | Link |
Software Developer
Join Date: Jun 2005
Location: Last House on Slunk Street
Posts: 13,248
|
Just a side note:
You can find a bunch of "uncompressed" sample files in YUV4MPEG (.y4m) here: http://media.xiph.org/video/derf/ These files are more convenient to use, also with x264
__________________
Go to https://standforukraine.com/ to find legitimate Ukrainian Charities 🇺🇦✊ |
27th March 2012, 15:20 | #36 | Link |
Registered User
Join Date: Jan 2012
Posts: 20
|
Thanks for the recommendation. Files with .y4m saves all the hassle. Anyway, back to the case of loop filter.
I already have a sample code of an simple MPEG-2 encoder and I'm to evaluate the performance of an MPEG-4's deblocking filter by "importing" this filter to the MPEG-2 architecture. While I have done a lot of readings on the theoretical parts on how a deblocking filter works, I am still confused with x264 code as they are just too lengthy. Will the deblocking filter of JM (http://iphome.hhi.de/suehring/tml/) be much simpler in order to achieve the same objective? Thank you. |
27th March 2012, 17:25 | #37 | Link | |
Registered User
Join Date: Mar 2005
Location: Finland
Posts: 2,641
|
Quote:
There's a standalone implementation of H.264's deblocking filter for AviSynth, if you don't need an in-loop filter. The source code might help understanding the in-loop version too. Last edited by nm; 27th March 2012 at 17:28. |
|
5th April 2012, 04:15 | #38 | Link |
Registered User
Join Date: Jan 2012
Posts: 20
|
Let's put the filter aside. Assume now I would like to encode a sequence of 5 images in PGM using x264 (by using img_%04d.pgm like in previously) into a video sequence. Is it possible to
1) explicitly define a higher encoding bitrate value for the first frame (I-frame) and another lower bit rate for another 4 frames? 2) separate the encoded video back into the 5 individual frames 3) compare the PSNR value between the frames in step 2 to their original frames before encoding. Thank you |
5th April 2012, 10:11 | #39 | Link | |||
Registered User
Join Date: Mar 2005
Location: Finland
Posts: 2,641
|
Quote:
Quote:
Code:
ffmpeg -i input.mp4 -f image2 frame-%03d.pgm Quote:
http://qpsnr.youlink.org/ http://avisynth.org/mediawiki/Compare http://compression.ru/video/quality_...t_tool_en.html PSNR is also pretty trivial to calculate yourself with a couple lines of code. Last edited by nm; 5th April 2012 at 10:22. |
|||
17th April 2012, 05:03 | #40 | Link | |
Registered User
Join Date: Jan 2012
Posts: 20
|
Quote:
To use qpfile, I just have to type the contents in a text file and name it qpfile and run it using --qpfile, right? I tried searching but there are very few sources teaching how to use qpfile command Thanks |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|