<p>25i and 50i are the same thing. 25i means "25 frames per second, interlaced". 50i means "50 fields per second", the latter implies interlaced video.</p>

<p>Likewise, 30i and 60i are the same thing. Basically, if the number before "i" is larger than 30 then it means number of fields, otherwise it is number of frames. All the existing interlaced systems I know of use 2 fields per frame. There were some systems that used 4 or even 8 fields per frame.</p>

<p>DVD are encoded to produce interlaced output. They also have flags that allow to save space by not repeating unneeded fields or frames. These flags are widely used in 60 Hz DVDs, I don't know how commonplace they are in 50 Hz DVDs. If the original title was a movie, you likely should treat it as 25p, not as 25i/50i or 50p.</p>

CC BY-SA 3.0
2018-04-25T16:57:38.930Z
2018-04-25T16:57:38.930Z
Rusty Core
<p>I have a DVD with footage which I want to convert to h264/h265. Mediainfo says that the video is 720x576, MPEG-2 encoded, PAL 25 fps and <strong>interlaced</strong> which is the first time I've seen that, usually 25 fps is progressive.<br>
Media Player Classic plays the video at 50 fps and applies deinterlacing, but VLC plays it at 25 fps without deinterlacing by default. I suspect that the metadata is incorrect, it should read 50i instead of 25i - is it possible?<br>
Is there a way to fix it? Avidemux, Virtualdub and others see the video as 25i and doubling the framerate to 50 either duplicates frames or uses frame-blending, both options look worse than what MPC manages to display.</p>

<p>Here is the Mediainfo's readout: <a href="https://pastebin.com/cWKsUraM" rel="nofollow noreferrer">https://pastebin.com/cWKsUraM</a></p>

CC BY-SA 3.0
2017-09-11T23:35:50.400Z
Paste the mediainfo readout about the file.
Gyan
CC BY-SA 4.0
2018-05-31T17:00:29.290Z
@Vlives, you pasted info about the newly encoded MKV, not about the original VOB.
Rusty Core
<framerate><vlc>
Metadata says the video is 25i, but MPC plays it as 50i
Vlives
# Metadata says the video is 25i, but MPC plays it as 50i

(Asked by: username_0 on 2017-09-11)

I have a DVD with footage which I want to convert to h264/h265. Mediainfo says that the video is 720x576, MPEG-2 encoded, PAL 25 fps and **interlaced** which is the first time I've seen that, usually 25 fps is progressive.  
Media Player Classic plays the video at 50 fps and applies deinterlacing, but VLC plays it at 25 fps without deinterlacing by default. I suspect that the metadata is incorrect, it should read 50i instead of 25i - is it possible?  
Is there a way to fix it? Avidemux, Virtualdub and others see the video as 25i and doubling the framerate to 50 either duplicates frames or uses frame-blending, both options look worse than what MPC manages to display.

Here is the Mediainfo's readout: <https://pastebin.com/cWKsUraM>

**Tags:** framerate, vlc

> **Comments:**
> **username_1**: Paste the mediainfo readout about the file.  
> **username_2**: @username_0, you pasted info about the newly encoded MKV, not about the original VOB.  

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## 1 answers

### Answer by username_2 on 2018-04-25. Score: 1

25i and 50i are the same thing. 25i means "25 frames per second, interlaced". 50i means "50 fields per second", the latter implies interlaced video.

Likewise, 30i and 60i are the same thing. Basically, if the number before "i" is larger than 30 then it means number of fields, otherwise it is number of frames. All the existing interlaced systems I know of use 2 fields per frame. There were some systems that used 4 or even 8 fields per frame.

DVD are encoded to produce interlaced output. They also have flags that allow to save space by not repeating unneeded fields or frames. These flags are widely used in 60 Hz DVDs, I don't know how commonplace they are in 50 Hz DVDs. If the original title was a movie, you likely should treat it as 25p, not as 25i/50i or 50p.


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