Dowloading from YouTube. Mp4? Or Flv?

[HitTheRoad]

What to choose if you're downloading from YouTube using a tool like Keepvid? Mp4? Flv? Or other formats?

[Baldrick]

mp4

[HitTheRoad]

Reason for this?
FLV files are bigger. But they aren't better?

[Baldrick]

Works on most devices.

But if you are going to play it on computers or reconvert it doesn't matter that much.

[HitTheRoad]

So there's no difference in audio and picture quality?

[pearlblack15]

So there's no difference in audio and picture quality?

FLV files have usually low picture quality. But most of the time youtube videos doesn't differentiate so much between FLV or MP4. But you may want to chose Mp4 for better compliance and better picture quality in HD videos.

[HitTheRoad]

In some cases, if there's a 480p FLV download available, the MP4 download goes up to 'Max 480p'. What to choose in those cases? 480p seems to give a higher picture quality than 'max 480p'.

[pearlblack15]

Sorry but I am no expert. I cannot say exactly. I guess max 480p is referring to the highest video resolution available for that particular video. So, If FLV is giving you better quality then go for it. But both are containers and they don't determine the quality of a video but the formats that are used to encode the video does (along with resoultion, bitrate etc and of course the source from where it was encoded). Mp4 generally uses AVC H.264 and FLV uses VP6 formats. H.264 is a modern day standard for video files generally and has better compression/size/quality compared to others.

Check this anyway: https://forum.videohelp.com/threads/320032-flv-vs-mp4-quality

P.S: I would go for MP4 as I find its quality better than FLV. At resolution greater than 480, MP4 is a choice and at lower, it doesn't matter so much.

[HitTheRoad]

PearlBlack15, Very informative. Thank you very much.

[Ethlred]

These days most of the FLVs on Youtube contain MP4 with AAC. So most of the time its MP4 in an FLV box.

[HitTheRoad]

These days most of the FLVs on Youtube contain MP4 with AAC. So most of the time its MP4 in an FLV box.

That's interesting! To test this I took an FLV video from YouTube, deleted the .flv extension and a added a .mp4 extension. I could play the video without any problem.
But... why is it that YouTube puts MP4's in an FLV box?

[Ai Haibara]

That's not quite an accurate test. As long as your system passes files with either extension to a player capable of playing what's IN the files, that 'test' should work. Try giving it the extension of a different movie the player supports (AVI/MKV/etc.).

To be absolutely sure, instead, just look at the videos' properties using MediaInfo.

[mgh]

flv and mp4 are containers. Youtube encodes everything nowadays with avc (h264) video and aac audio., or to webm format. For the avc video and aac audio it uses either mp4 container or flv container.

Download the highest resolution available in mp4 or flv, avoid webm if possible.

[HitTheRoad]

I used MPEG Streamclip to analyse the differences between the FLV and MP4 video. It appears both have a H.264 codec, but he FLV video has a higher resolution and bitrate.
I think I will go for the FLV video's, and than change the .flv extension to .mp4.


[Attachment 16234 - Click to enlarge]
[Attachment 16235 - Click to enlarge]

[Baldrick]

If you want a real mp4 you should remux(no reconversion). Maybe subler can do that in mac. In windows can you use mymp4boxgui.

[Ai Haibara]

You might be better off using VideoSpec or iMediaHUD to check the properties of video files, as it might provide more information. I can't remember how much MPEG Streamclip provides in the way of details, unfortunately.

I'd say that if it's not a hassle, just pick the highest quality version YouTube provides, and if it provides both MP4 and FLV containers, download both, and judge which version looks better, to you.

[HitTheRoad]

If you want a real mp4 you should remux

I just tried Remux for the Mac. It works great. But... why doesn't changing the extensions work the same way, to make a mp4 from an Flv?

I'd say that if it's not a hassle, just pick the highest quality version YouTube provides, and if it provides both MP4 and FLV containers, download both, and judge which version looks better, to you.

Thanks! I'll do just that.

[Ethlred]

Avidemux 2.6.0 which is beta version and NOT as unstable as the stable version will do it. Set the video and the audio to copy and the box to MP4 and then save.

I just tried it with an Aeorobicise (remember to breath out) video and it worked fine. I tried mymp4boxgui and I could not find a way to do it. Tried the latest as well as the one I had installed when I opened this reply box. Mux oh dear it only has a video track, OK then use the FLV again for the audio track, Oh dear you cannot have to video tracks. OK THEN how demux first. Choose a file drag and drop works IF you drop in the file entry box. Hit the demux button

OK then what happened. Nothing. Same file in Avidemux works fine. Well almost fine as Mediainfo says the frame rate which was a 29.970 constant is now a variable frame rate and I don't see a way to adjust that.

Maybe there is a secret setting I am missing. For both programs.

[Ethlred]

I see that one thing I was missing is that Avidemux has newer versions and one newer than the Beta I used.

Trying 2.6.1

Still outputting variable frame rate. But unlike the old 2.5.9 it doesn't choke on the file.

OK try Video Filters Resample FPS to 29.970

It still forgets what folder was used last. Wants to save in its own folder and that is a MS no no.

And the bloody thing is still variable.

Video Filters Change Frame rate to 29.970

Apparently it either won't do it in a copy operation or it does not have a clue as what a constant frame rate is.

Reset filters and tried saving as MP4v2 and the file is smaller BUT still VFR.

MKV and I know that isn't what the OP wants but I WANT TO TRY. I am stubborn sometimes.

The file is a bit smaller still AND SURPRISE

Frame rate mode : Constant
Frame rate : 29.970 fps


Bloody well about time but WHY?

OK then close file and load the MKV and save as MP4

Well at least it is consistent. VFR.

Just because I must know and want to do this anyway I am concatenating two FLVs into a single MP4

Original FLVs
Frame rate mode : Constant
Frame rate : 23.976 fps

New MP4
Frame rate mode : Variable
Frame rate : 23.976 fps
Minimum frame rate : 23.810 fps
Maximum frame rate : 24.390 fps

and that is bit stupid.

Save as MKV

This time the MKV is slightly larger and

Frame rate mode : Constant
Frame rate : 23.976 fps

Clearly the program is not working quite right with MP4s.


Latest beta does the same thing only its slower at responding to a file dropped on it. Going back the non beta. For once the stable version is the better choice.

[Tom Saurus]

I use Freemake Video Downloader quite a bit to download YouTube videos. I have a LG Blu Ray player and it can play quite a few of the .flv videos I have downloaded. What I have noticed is that if one wants to pause or skip ahead or back in the .flv that you can't do that. But if you download the file as an .mp4 you can pause and skip ahead or back via the LG Blu Ray player. This can be quite an important factor in the enjoyment of watching a YouTube video.

Also is you are downloading multiple files that need to be patched together later as one file. Like if something is split into 10 or 15 minute chunks, use a video downloader that allows you to see the specs of each segment. I usually pick the 360p option. Sometimes you can have a high percentage of chunks that are 480p and a few that only offer 360p.

I can of course convert my .flv files to .mkv files, but since .mp4 files will play on my LG Blu Ray player I am choosing that more and more now.

I use Freemake Video Converter to patch together several .flv or .mp4 segments and I used to export as .avi files but now I chose .mkv. If the specs all match up it is a fairly fast process, though it is re encoding the files.

[Hoser Rob]

My curiosity was piqued, so I found this list of youtube supported video formats on google.com:

Make sure that you’re using one of the following formats:

• .MOV
• .MPEG4
• .AVI
• .WMV
• .MPEGPS
• .FLV
• 3GPP
• WebM

The thing is, how would you be supposed to know which format to download?

[pearlblack15]

@Hoser, those are the types of video you can upload to youtube not download. Youtube never talks about downloading a video from their site. Just download any type of file, be it FLV or MP4 (at higher resolution i.e HD videos) or Webm (sometimes) or 3GP (for low resolution, smaller files, worse quality)

[DarrellS]

MP4 might be 320x240 for phone where FLV might be 1080p. As mentioned above, the FLV file is AVC/AAC in a FLV container. I use a Greasemonkey script for Firefox called Youtube HD Suite which automatically plays the best quality video and shows all available files at top of page to download by right clicking>save as.

For converting these FLV files to MP4, I use a ffmpeg batch file to copy the AVC/AAC into an MP4 container. You must have a copy of ffmpeg.exe in the folder that you are going to convert. Copy below text into notepad and save as FLV2MP4.bat and doubleclick. All FLV files in folder will be converted to MP4...

for %%a in ("*.flv") do ffmpeg -i %%a -vcodec copy -acodec copy %%~na.mp4

You'll need to make sure there are no spaces in the file names or they will be ignored. To replace the spaces with a dash -, create an AVSscript and save as "replace-space-with dash.avs"

dim objFileSys, file, folderName, folderObj, fileColl, objRegEx, newFile

set objFileSys = CreateObject("Scripting.FileSystemObject")
folderName = InputBox("Enter the full path where the files are located.", "Full path is required")

set folderObj = objFileSys.GetFolder(folderName)
set fileColl = folderObj.Files
set objRegEx = new RegExp

objRegEx.Pattern = " " ' the pattern is one space
objRegEx.Global = true

for each objFile in fileColl
newFile = objRegEx.Replace(objFile.Name, "-") ' each pattern gets replaced with one dash

objFileSys.MoveFile objFile, folderName & "\" & newFile
next


If you'd rather replace the space with an underscore _, then change this line...

newFile = objRegEx.Replace(objFile.Name, "-") ' each pattern gets replaced with one dash

to

newFile = objRegEx.Replace(objFile.Name, "_") ' each pattern gets replaced with one underscore