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  1. In some PAL movies the audio sounds faster than in the original NTSC version. Is there a program to detect it?
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  2. Member Cornucopia's Avatar
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    Detect what? The only way you know something is faster (or slower) is when you have something as a reference to compare against (other than the obvious darth vader or chipmunk)

    24 (or 23.976) fps -> 25 fps is a 4% speedup, which is less than a semitone (~5.5%). Some people with perfect pitch can tell that it is off and by how much, some can tell that something is off but not sure what or how, some cannot tell the difference unless hearing back to back comparison, and some cannot tell the difference even with a comparison.

    The reason some movies have this while others don't has to do with different cost/complexity/effort in one method versus the other. The cheap & easy & bad way is to convert 24->25 by keeping all frames but making each duration shorter (which makes the total duration shorter). Then you have to speed up the audio to maintain sync. The speedup in samperate needs an accompanying counter-samplerate convert to bring the samplerate back to traditional common rates (44.1kHz, 48kHz, etc).
    The better way does this too, but also incorporates a countering pitch change as well. There are different ways to do this with varying levels of quality.
    And, back before digital, it was nearly impossible to do a pitch change (except rotating head tape), so the speedup was the only viable option.

    Scott
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  3. Member azmoth's Avatar
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    Be a miracle if there were. The only test is your hearing. Try listening to the Pal boxset of The Sopranos and the chipmunk voice of Tony's wife(Edi Falco)will wear you down. On R1 far different! I hate that Pal speedup and as far as I know there never ever is a pitch correction on commercial movie DVD from NTSC to pal unless it is some music passage or some weird hybrid dvd.
    Last edited by azmoth; 14th Mar 2020 at 05:47.
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  4. With my smart FFmpeg gui, audio modify section, you can correct that.
    https://forum.videohelp.com/threads/395425-New-small-GUI-for-FFmpeg
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    Originally Posted by Cornucopia View Post
    ... 24 (or 23.976) fps -> 25 fps is a 4% speedup, which is less than a semitone (~5.5%). Some people with perfect pitch can tell that it is off and by how much, some can tell that something is off but not sure what or how, some cannot tell the difference unless hearing back to back comparison, and some cannot tell the difference even with a comparison. ...
    I agree with your point overall but if you can't hear a difference of almost a semitone you are pretty much tone deaf, and I defiinitely don't have perfect pitch myself.
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  6. Originally Posted by azmoth View Post
    Be a miracle if there were. The only test is your hearing.
    What a bunch of nonsense. I don't know of any software that does it -- but since one can hear the difference it's possible to write a program to detect it. And given the pitch shift is about 2/3 of a semitone software could tell if the music is off-pitch even without an NTSC reference. This wouldn't be foolproof (not all music is recorded at concert pitch, sometimes the pitch isn't raised by the conversion) but it would work for a large percentage of videos.
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  7. Member Cornucopia's Avatar
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    No, the reason you can detect it is because:
    1. You are sensitive enough to it.
    2. You have a body of world knowledge and experience to draw against as reference comparison.
    Unless using AI & neural net & ref database (Alexa?), software can't do that.
    The process to perform the change is straightforward, and exact. The software to detect is not.

    And the OP was talking about shows & movies - that may have some music but much of it is dialogue - much harder to tell the difference. Without having to be "tone deaf" (which a large portion of the population do suffer from).

    Scott
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  8. Member azmoth's Avatar
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    Originally Posted by jagabo View Post
    Originally Posted by azmoth View Post
    Be a miracle if there were. The only test is your hearing.
    What a bunch of nonsense. I don't know of any software that does it -- but since one can hear the difference it's possible to write a program to detect it. And given the pitch shift is about 2/3 of a semitone software could tell if the music is off-pitch even without an NTSC reference. This wouldn't be foolproof (not all music is recorded at concert pitch, sometimes the pitch isn't raised by the conversion) but it would work for a large percentage of videos.
    Relax, read the the original question again. OP is talking about 'Movies.' I appreciate what I had written may not be very helpful(off the cuff!), but one's hearing is aways the best option of determination regarding the film world(many don't notice the difference due to hearing ability) and that is the subject isn't it and not your divergence to music concerts?
    Last edited by azmoth; 14th Mar 2020 at 10:58.
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  9. Originally Posted by Cornucopia View Post
    No, the reason you can detect it is because:
    1. You are sensitive enough to it.
    2. You have a body of world knowledge and experience to draw against as reference comparison.
    Unless using AI & neural net & ref database (Alexa?), software can't do that.
    There's only one thing you need t know about the real world: Since 1939 most music has been tuned with middle A at 440 Hz. Virtually every movie soundtract is produced at that "concert pitch". Not only does middle A appear at 440 Hz but all notes on the 12-tone scale fall at specific frequencies relative to that base. It's easy to identify the exact frequencies of a musical waveform in software. If all the notes fall between those expected frequencies, and are off by +4.27 percent, you can be pretty sure the soundtrack has been through a PAL speedup. As I said, this isn't absolutely foolproof but will work most of the time.
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  10. Thank you.
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  11. Originally Posted by azmoth View Post
    Relax, read the the original question again. OP is talking about 'Movies.'... not your divergence to music concerts?
    How many movies do you know with no music?

    Originally Posted by azmoth View Post
    one's hearing is aways the best option of determination regarding the film world(many don't notice the difference due to hearing ability)
    If someone can't hear the difference how is that the best option?
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  12. Originally Posted by jagabo View Post
    Originally Posted by Cornucopia View Post
    No, the reason you can detect it is because:
    1. You are sensitive enough to it.
    2. You have a body of world knowledge and experience to draw against as reference comparison.
    Unless using AI & neural net & ref database (Alexa?), software can't do that.
    There's only one thing you need t know about the real world: Since 1939 most music has been tuned with middle A at 440 Hz. Virtually every movie soundtract is produced at that "concert pitch". Not only does middle A appear at 440 Hz but all notes on the 12-tone scale fall at specific frequencies relative to that base. It's easy to identify the exact frequencies of a musical waveform in software. If all the notes fall between those expected frequencies, and are off by +4.27 percent, you can be pretty sure the soundtrack has been through a PAL speedup. As I said, this isn't absolutely foolproof but will work most of the time.
    Interesting approach. Should work for music, but would fail for speech (voice) as human voices are not calibrated. A movie w/o music is for example "No Country for Old Men" IIRC.
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  13. Member Cornucopia's Avatar
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    Hate to break it to you, but that is a false presumption: VERY many recordings both popular and classical DO NOT strictly tune to A440. Some times they do, then shift everything up or down for a different musical effect. Some straight tune to other pitches for a similar reason.

    As a musician, when I was first learning and we would play along w recordings (both analog & digital) to master a song or lick, it is not an exaggeration to say that one would need to retune for each song in order to match the CONSTANT changes in tune (not key, that's a given) from song to song.
    And, NO, neither my playback system nor my instrument were of inferior quality - they did not need more than occasional tuning adjustment.
    One thing that you fail to take into account is that when tuning non-electronic instruments, the acoustic pitch is affected by the speed of sound, which varies by such environmental factors as pressure (altitude), temperature (season), and even a small amount by humidity. A person with "perfect pitch" making a recording and tuning adjustments is still doing so under the jurisdiction of their environment at the time. And other instruments are usually tuned to match with the harder-to-tune acoustic ones (in symphonic concerts, it is often the oboe). Then when recorded, it is baked into the recording.
    Electronic, and even moreso the digital ones, improve on this, but you know as well as anyone that generated reference tones can vary by power supply and samplerate clocks are also not universally accurate.

    Scott
    Last edited by Cornucopia; 14th Mar 2020 at 19:07.
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  14. Originally Posted by Cornucopia View Post
    The better way does this too, but also incorporates a countering pitch change as well. There are different ways to do this with varying levels of quality.
    In your opinion, which method provides the best quality?
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  15. Member Cornucopia's Avatar
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    Back when I was doing this on a regular basis, the best one was some Mac freeware app (can't remember the name) that used a polyphase filter method using multitap FIR filters.
    As an example, I had to speed up a piece of music quite a bit for a dance event that I was hired to run audio for. The speedup raised the tone up a Major3rd (aka 4 semitones or at least 23%. Had to pitch it back down to that of the original recording without either the speedup SRC nor the pitchdown adding such artifacts as to make it unusable. That app was one of the few that could do it decently - left it with a bit of a shimmery, more echoey quality, but that's all.
    I've also used Avid's ProTools pitch correction tool often, to good (if a little "brittle") effect. Especially when having to do those stupid commercial disclaimers where they speed it up to get all the legalese to fit. Not to brag, but I haven't heard ANY recording, then or since, that could do that so drastically and still sound as reasonably natural. (I still have a few secrets in my professional bag of tricks).

    But I would assume that technology has greatly improved options since then, and expect that any major pro NLE or DAW would now have a PitchCorrect/AutoTune/TempoAdjust + SRC tool that can do a decent job.
    Haven't tried it myself (I fall back on doing it in ProTools or Audition these days), but Audacity has a P.C. tool that you could try...

    Scott
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  16. Originally Posted by Cornucopia View Post
    As a musician, when I was first learning and we would play along w recordings (both analog & digital) to master a song or lick, it is not an exaggeration to say that one would need to retune for each song in order to match the CONSTANT changes in tune (not key, that's a given) from song to song.
    And, NO, neither my playback system nor my instrument were of inferior quality - they did not need more than occasional tuning adjustment.
    One thing that you fail to take into account is that when tuning non-electronic instruments, the acoustic pitch is affected by the speed of sound, which varies by such environmental factors as pressure (altitude), temperature (season), and even a small amount by humidity. A person with "perfect pitch" making a recording and tuning adjustments is still doing so under the jurisdiction of their environment at the time. And other instruments are usually tuned to match with the harder-to-tune acoustic ones (in symphonic concerts, it is often the oboe). Then when recorded, it is baked into the recording.
    Electronic, and even moreso the digital ones, improve on this, but you know as well as anyone that generated reference tones can vary by power supply and samplerate clocks are also not universally accurate.
    Interesting. I wasn't aware of the tuning practices, like following the status of the harder-to-tune instruments etc. But yes, it's definitely not easy to tune a piano in short time. So after all it could be that the 4% pitch-shifted PAL variant is closer to the 'true original' than we think?
    Concerning the frequency references: I understand that even the 'unintentional' deviations due to temperature drift etc. of the (mechanical-accoustic) reference equipment can become as much as 4% within the limited temperature range of recording locations (concert halls, studios)? Well, I would have to check the physics schoolbooks ....
    Propagation delays (speed of sound) do actually not alter the frequency unless for moving objects (doppler effect), however if the propagation delay is frequency dependent we get what is called 'dispersion'. Whether dispersion is perceived as 'pitch shift' I doubt a bit, I am however no expert.
    As for modern electronic frequency references the overall deviations due to equipment imperfections is in the range of some ppm (parts per million) unless it's really crap, hence a fraction of a Hertz (typically less than +/- 0.05 Hz error) which has no practical relevance, I believe.
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  17. Member azmoth's Avatar
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    Originally Posted by jagabo View Post
    Originally Posted by azmoth View Post
    Relax, read the the original question again. OP is talking about 'Movies.'... not your divergence to music concerts?
    How many movies do you know with no music?

    Originally Posted by azmoth View Post
    one's hearing is aways the best option of determination regarding the film world(many don't notice the difference due to hearing ability)
    If someone can't hear the difference how is that the best option?
    You seem determined to shift the emphasis to music for some reason. All movies have some form of music and fair percentage incidental music, leading in or leading out at the end credits. Nothing too much which would constitute the viewer to comment on chipmunk voices or wow "I noticed that pitch change!" Even just a song would not constitute a problem.

    Not hearing the difference is the best option(figuratively speaking), because then you wouldn't care as you don't notice anyway, as most do not due to some range of frequency loss, old age etc or listening to music at loud levels which might have caused it. Let's us also not include too the timbre of sound and harmonics to further complicate things and give you more to focus on. No doubt you will make something more of this as you are determined to make the OP's question about music. Feel free to explore.
    Image Attached Thumbnails Timbre_Affects_Pitch.pdf  

    Last edited by azmoth; 15th Mar 2020 at 04:51. Reason: Added pdf!
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  18. My 2 cents worth.... I live in PAL land and I'm not sure I've come across a movie or TV show that wasn't simply sped up from NTSC to PAL speed without any pitch correction (unless the frame rate was converted rather than sped up). All of it. Dialogue, title music and background music etc. Having said that, it doesn't tend to bother me unless I've also heard the audio at it's original speed. I remember watching season one of a TV series on PAL DVDs without thinking about audio pitch, but after buying the second season as NTSC and going back to season one I couldn't stand listening to it. I suspect it requires magic ears to be certain the pitch has increased without the original as a reference, and it depends how familiar you are with something. I remember upsetting a friend years ago after he demo'd his new, very expensive Hi-Fi system and I told him I thought it sounded great, but the turntable was spinning a tad slow. After arguing about it he eventually agreed to check, and it was slow by a little under 1/3 of a revolution per minute. I don't have perfect pitch, but he happened to play an album I'd listened to so many times the pitch must have become burned into my sub-conscience.

    "Music videos" are a different story. Concerts.... that sort of thing. I've not been able to compare many PAL and NTSC versions, but I'm pretty sure the ones I have were either pitch corrected when sped-up for PAL, or it was the original audio and the frame rate was converted to 25fps using a method that doesn't change the duration.

    villaquien,
    If you happen to use a PC as a media player you can adjust the frame rate and audio speed, and optionally correct the pitch "on the fly" with ReClock. Keep in mind though, a PAL source shot/filmed at 25fps won't have sped-up audio.
    Last edited by hello_hello; 30th Mar 2020 at 23:21.
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  19. Many PAL movies were simply converted from NTSC originals.
    Very often the master audio track (with sounds, music, etc., without speech) was simply converted as well.
    The pitch is then automatically changed without any corrections.
    If you only watch the movie, you will not notice any difference.
    On the other hand, if you e.g. record the PAL movie from the TV and want to add the missing trailer from an NTSC DVD, you will notice the different pitch immediately.
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