Hello,
I have a new question regarding transcoding.
In another test of mine, I decided to re-encode an MPEG-2 video in H.264 and the results weren’t too good. When playing back the H.264 file on my TV & Blu-ray Player, the motion didn’t look quite right. Can anyone explain the reason behind this?
Hi
The degree of loss depends on the video format you start with and resolution, eg for one transcode and taking the two extremes:
The results from other combinations will be somewhere in between the above 2
IMHO transcoding of a compressed video format to another should be the option of necessity - eg you do not have the original project to be able to re-export to the required format.
HTH
John EB
Hi
The degree of loss depends on the video format you start with and resolution, eg for one transcode and taking the two extremes:
- an uncompressed or lightly compressed video format, the loss of quality will be minimised if you are matching resolutions.
- highly compressed video and/or you are upscaling at the same time there is going to be a loss of quality - how much will vary depending on the relative compression ratios and/or the degree of upscaling.
The results from other combinations will be somewhere in between the above 2
IMHO transcoding of a compressed video format to another should be the option of necessity - eg you do not have the original project to be able to re-export to the required format.
HTH
John EB
Hi John, thanks for your answer. So, in other words, if the original files are MPEG-2, then you should stick to MPEG-2 when re-encoding after editing?
The files that I’ve been using to test this out with were originally recorded on an old mini-DVD camcorder and so are in MPEG-2 720x576i, 25fps & 4:3 aspect ratio. So does re-encoding that with H.264 cause some sort of clash somewhere? As in why the motion in the H.264 video looks a bit off.
Hi
. . . . if the original files are MPEG-2, then you should stick to MPEG-2 when re-encoding after editing . . . .
The answer depends on what the final usage destination is, if the end usage device supports MPEG-2 or you are creating a Blu-Ray disc (which also supports the MPEG-2 codec as well as the h.264) then yes stick to that format.
If you are wanting a disc burning then burn to DVD format which is 576i, not Blu-Ray, and let the player/TV do the upscaling.
If the end usage device does not support MPEG-2 then you have no choice other than to export with subsequent re-encoding to a supported format.
. . . . So does re-encoding that with H.264 cause some sort of clash somewhere? As in why the motion in the H.264 video looks a bit off . . . .
The motion issue is probably due to changing from 576i, interlaced video, to 576p progressive video and is worse when there is motion across the screen or panning present - this does assume you are not upscaling as well.
Interlaced video is much better for playback where there is movement/panning across the screen than progressive video for the same framerate.
You could try exporting to h.264 at 50fps ensuring the Interpolate intermediate images of the Speed effect option is checked for all the video objects on the timeline this may give some improvement on the motion at the expense of a slightly softer image. I counteract this by applying an overall sharpening to the project with a value of 30 using the Effects, Movie Effects settings option - I actually do this for all projects irrespective of framerate change.
HTH
John EB
Hi
. . . . if the original files are MPEG-2, then you should stick to MPEG-2 when re-encoding after editing . . . .
The answer depends on what the final usage destination is, if the end usage device supports MPEG-2 or you are creating a Blu-Ray disc (which also supports the MPEG-2 codec as well as the h.264) then yes stick to that format.
If you are wanting a disc burning then burn to DVD format which is 576i, not Blu-Ray, and let the player/TV do the upscaling.
If the end usage device does not support MPEG-2 then you have no choice other than to export with subsequent re-encoding to a supported format.
. . . . So does re-encoding that with H.264 cause some sort of clash somewhere? As in why the motion in the H.264 video looks a bit off . . . .
The motion issue is probably due to changing from 576i, interlaced video, to 576p progressive video and is worse when there is motion across the screen or panning present - this does assume you are not upscaling as well.
Interlaced video is much better for playback where there is movement/panning across the screen than progressive video for the same framerate.
You could try exporting to h.264 at 50fps ensuring the Interpolate intermediate images of the Speed effect option is checked for all the video objects on the timeline this may give some improvement on the motion at the expense of a slightly softer image. I counteract this by applying an overall sharpening to the project with a value of 30 using the Effects, Movie Effects settings option - I actually do this for all projects irrespective of framerate change.
HTH
John EB
Hi John,
Okay, I’ll try that out and let you know the result. And, also, I did export as 576i.
And, also, I did export as 576i.
Normal MEP 2021 export to MP4 (H264) is Progressive. The Interlaced setting can't be selected.
I've done a lot of MPEG2>MP4 with MEP and haven't noticed any problems with motion.
For info, If I'm going to output MPEG 2 after editing an MPEG 2 source, I'll use the Main Concept encoder, as that will smart-render the video, saving a re-encode. I don't know whether MPE 2022 allows use of the Main Concept MPEG 2 encoder.
I've also changed my philosophy on MPEG 2: since HD storage is so cheap, I now leave my video in MPEG 2 instead of converting to MP4, which would result in slightly less quality unless the bitrate is high, defeating the purpose of the re-encode.
Hi Al.
It may not have been Magix's choice.
Licence agreements are not perpetual and may not have been renewable or the volume cost to Magix may have been increased to an unacceptable level for for them. The supplied Main Concept build has always been the 2012 version. That is not the build version currently on offer from Main Concept.
Ray.
I've done a lot of MPEG2>MP4 with MEP and haven't noticed any problems with motion.
Hi,
It’s the MainConcept encoder that I’ve been using.
It’s the MainConcept encoder that I’ve been using.
In that case, try the default MPEG 4 encoder.
My previous post related to outputting MPEG 2.
What version MEP are you on (tip: put it in your forum signature)?
Hello,
I have a new question regarding transcoding.
In another test of mine, I decided to re-encode an MPEG-2 video in H.264 and the results weren’t too good. When playing back the H.264 file on my TV & Blu-ray Player, the motion didn’t look quite right. Can anyone explain the reason behind this?
It’s the MainConcept encoder that I’ve been using.
In that case, try the default MPEG 4 encoder.
My previous post related to outputting MPEG 2.
What version MEP are you on (tip: put it in your forum signature)?
Ok, I’ll try that. Is the default encoder a Magix encoder or something? And, I’m currently using MEP 2018 Premium.
Is the default encoder a Magix encoder or something?
Don't know. A more knowledgeable type will be along shortly to enlighten us! 👍
Is the default encoder a Magix encoder or something?
Don't know. A more knowledgeable type will be along shortly to enlighten us! 👍
Well on my version of it there isn’t even an option for 2-pass. And for some reason you can’t choose to use constant bitrate (if you ever wanted to), and you can’t change from Progressive to interlaced either. Just seems a bit limited with what you can do compared to the MainConcept encoder.
@AAProds @jak.willis @johnebaker
I don't know for certain but knowing that most companies will look for free coding where they can to help build up a product (even my car is mainly run of freeware coding) I would say all the clues are on this portion of information regarding the whole of how Magix build their programs up.
Pay particular attention to the bit I have boxed in yellow.
Look up Windows Media Technologies will eventually bring you to this page.
Look familiar?
Looking at all the other companies mentioned on that page soon brings you to the base coding for most in the in house effects used and building blocks to integrate everything.
Ray.
Well on my version of it there isn’t even an option for 2-pass. And for some reason you can’t choose to use constant bitrate (if you ever wanted to), and you can’t change from Progressive to interlaced either. Just seems a bit limited with what you can do compared to the MainConcept encoder.
True. Many here, though, just use the default because they think it's better.
I wouldn't be interlacing MP4; I don't think it's designed for that. As I mentioned before, unless disk space is a premium, I'd be editing the MPEG 2 file, then using the Main Concept MPEG 2 encoder (different dropdown to the MPEG 4 encoder) to encode it to MPEG 2. That way you'll be able to smart-render. All the tech players/TVs can play back MPEG 2 and as John says, the de-interlacing is handled well by the player/TV.
If however you're making Youtube videos, they should be MP4 Progessive. You can give YT interlaced but it likes Prog.
Well on my version of it there isn’t even an option for 2-pass. And for some reason you can’t choose to use constant bitrate (if you ever wanted to), and you can’t change from Progressive to interlaced either. Just seems a bit limited with what you can do compared to the MainConcept encoder.
True. Many here, though, just use the default because they think it's better.
I wouldn't be interlacing MP4; I don't think it's designed for that. As I mentioned before, unless disk space is a premium, I'd be editing the MPEG 2 file, then using the Main Concept MPEG 2 encoder (different dropdown to the MPEG 4 encoder) to encode it to MPEG 2. That way you'll be able to smart-render. All the tech players/TVs can play back MPEG 2 and as John says, the de-interlacing is handled well by the player/TV.
If however you're making Youtube videos, they should be MP4 Progessive. You can give YT interlaced but it likes Prog.
Yeah. So MPEG-2 should stay as MPEG-2? That seems to give me best results. And, also, when you say about smart rendering, what if you’ve been editing using effects, etc? I thought that smart rendering was only possible if you haven’t edited the video in any way apart from trims & cuts.
Hi
. . . . Is the default encoder a Magix encoder or something? . . . .
I don't know for definite either - from the dll naming it could be the Intel QSV encoder.
. . . . I thought that smart rendering was only possible if you haven’t edited the video in any way apart from trims & cuts. . . .
You are correct, even then it is still very finnicky on the video formats it will Smart render/Smart copy.
Hi Ray
. . . . Look familiar? . . .
Yes, they are the Microsoft VP9 extensions for VP9, which is not h.264 nor is it owned by Microsoft, it is a Google codec. The extensions enable the VP9 codec to be used on Windows software.
John EB
@johnebaker @jak.willis @AAProds
Hi John.
I don't remember saying Microsoft owned VP9, you are correct it is a Google based codec which is open source and royalty free. I think you are correct saying its source is from Intel as the manuals refer to it as the Intel codec but I think Magix uses the Microsoft codecs used within their players as Microsoft hint that the codec can be used via third party apps and is capable of encoding.
Depending on which export option you decide to use with the Magix standard set of codecs you can come across this bit of information regarding smart render.
You can also certainly choose to interlace video exports.
Original interlaced video though (and this is for Jaks benefit) has 60 frames for a 30fps clip. Two images for one frame (interlaced) which means two things. Each clip is slightly out of sync time wise as one is recorded before the other and then combined. This can cause problems under certain conditions as explained in the VPX manual.
Once you combine those frames to progressive they can't be separated again and you have say 30 frames rather than the original 60. Trying to interlace them after would mean producing more frames to be interlaced. That could be the 'odd movement' you are seeing. Especially if you have downloaded interlaced footage that has already been combined into a progressive file.
I don't see where there are many less encoding options with the Magix supplied codec. Most of what is missing is where people can set the wrong parameters and end up with a null bit file. Yes it is a bit dumbed down but I personally think intelligently so or we would be getting more people getting lost with codecs than we do at present.
Or why people think there are no constant bit rate options. They are there for when they may be needed.
Ray.
@johnebaker @jak.willis @AAProds
Hi John.
I don't remember saying Microsoft owned VP9, you are correct it is a Google based codec which is open source and royalty free. I think you are correct saying its source is from Intel as the manuals refer to it as the Intel codec but I think Magix uses the Microsoft codecs used within their players as Microsoft hint that the codec can be used via third party apps and is capable of encoding.
Depending on which export option you decide to use with the Magix standard set of codecs you can come across this bit of information regarding smart render.
You can also certainly choose to interlace video exports.
Original interlaced video though (and this is for Jaks benefit) has 60 frames for a 30fps clip. Two images for one frame (interlaced) which means two things. Each clip is slightly out of sync time wise as one is recorded before the other and then combined. This can cause problems under certain conditions as explained in the VPX manual.
Once you combine those frames to progressive they can't be separated again and you have say 30 frames rather than the original 60. Trying to interlace them after would mean producing more frames to be interlaced. That could be the 'odd movement' you are seeing. Especially if you have downloaded interlaced footage that has already been combined into a progressive file.
I don't see where there are many less encoding options with the Magix supplied codec. Most of what is missing is where people can set the wrong parameters and end up with a null bit file. Yes it is a bit dumbed down but I personally think intelligently so or we would be getting more people getting lost with codecs than we do at present.
Or why people think there are no constant bit rate options. They are there for when they may be needed.
Ray.
Hi Ray,
Thanks for the information. I was actually referring to the default encoder for MPEG-4. With that you aren’t able to select interlaced or constant bitrate options. Or at least on my version you can’t. And there’s no option for 2-pass either.
Hi Jak.
The lack of inclusion could be down to MPEG-4 not being fully compatible with all Blu-ray and DVD players whereas the Magix supplied MPEG-2 should be. I personally see little point in both duplicating the others abilities. Others may have a different viewpoint.
Also not all MPEG-4 converters are free but have patents and licences attached to them. There are over two dozen companies claim to have patents covering MPEG-4 but so far no licences have been granted to third parties from the licence holders as far as I'm aware or can research.
Maybe someone else know differently. I also found the following quote about MPEG-4.
"Most of the features included in MPEG-4 are left to individual developers to decide whether or not to implement. This means that there are probably no complete implementations of the entire MPEG-4 set of standards. To deal with this, the standard includes the concept of "profiles" and "levels", allowing a specific set of capabilities to be defined in a manner appropriate for a subset of applications"
Ray.
Hi Jak.
The lack of inclusion could be down to MPEG-4 not being fully compatible with all Blu-ray and DVD players whereas the Magix supplied MPEG-2 should be. I personally see little point in both duplicating the others abilities. Others may have a different viewpoint.
Also not all MPEG-4 converters are free but have patents and licences attached to them. There are over two dozen companies claim to have patents covering MPEG-4 but so far no licences have been granted to third parties from the licence holders as far as I'm aware or can research.
Maybe someone else know differently. I also found the following quote about MPEG-4.
"Most of the features included in MPEG-4 are left to individual developers to decide whether or not to implement. This means that there are probably no complete implementations of the entire MPEG-4 set of standards. To deal with this, the standard includes the concept of "profiles" and "levels", allowing a specific set of capabilities to be defined in a manner appropriate for a subset of applications"
Ray.
Thank you, Ray.
It just seems a bit strange not to offer an option for 2-pass encoding. Especially when 2-pass encoding is usually recommended as it gives the best results because it allows the encoder to make better decisions on where to allocate more bits and where to use less bits.
Hi
I was actually referring to the default encoder for MPEG-4. With that you aren’t able to select interlaced or constant bitrate options. Or at least on my version you can’t. And there’s no option for 2-pass either.
Are you referring to video export or burning to disc.
If video export, then h.264 is a progressive format by default, it is not supposed to be interlaced, though this is possible, however not practical as most of the devices that play MP4 video files are progressive devices. TV's are the only devices that started out as interlaced playback devices and then later added support for progressive.
As @CubeAce mentioned earlier:
- 'Most of what is missing is where people can set the wrong parameters and end up with a null bit file'
I would second this and also add that makes it easier and quicker to end up with something that is poor quality, not playable or a massive file size - this particularly is aimed at the Constant Bitrate option - this as I mentioned before will .
The Constant Bitrate option has been mentioned in one of your previous topics and is inferior to VBR if you want to ensure the best quality of the video. @Scenestealer also commented on this in your topic here .
The 2 - pass encoding allows you to target a file size more accurately then single pass, however the file size differences are minimal. it does not affect quality to any noticeable visible difference.
John EB
h.264 is a progressive format by default, it is not supposed to be interlaced
I didn’t realise this. So if that’s the case then could that be the reason why the motion isn’t very good? Because the source files are interlaced.
Hi Jak
@CubeAce - Ray gave a very good explanation of the issue converting interlaced to progressive in his post 6 above this one.
John EB