- Posts: 3
- Joined: Sat Apr 12, 2025 8:31 am
- Real Name: Alessandro Lofaro
Sat Apr 12, 2025 6:04 pm
Hi,
I got a kind of strange question, and yes, I looked at the manual before asking.
Situation: I got some files at least part of which I will probably even delete because I dont' think they are important, but for the time being, I am just trying to reduce the occupied space, especially for the bigger ones, while I wait to put the time aside to go through them and decide which ones to delete.
Many of the bigger ones turns out are already H264, but 29.97fps, someone must have thought about USA TV standards.
Since I have a full Studio license of Resolve for other purposes (so, why not use it ?), and since even without "batch transcoding" called this way, the media management ends up being usable to do basically the same, I was thinking to transcode them to H265 25fps with some optimisation, for me is good enough, and doing some test file, I saw the reduction in size was quite nice, e.g. ca 800MB on a 3.67GB file.
In configuring I touched only the video part, left the audio as it was.
I then tried to look at a file to check the quality, confirming with the original, and that at the resolution i was using to watch it (not even full screen), there was not visible difference (I set to keep the original resolution, no rescaling), and I realised I had forgotten something.
The audio is synced for 29.97fps, so in theory, taking out the 4.97 fps, even if the whole video is just some 45', one hour or so, the audio is supposed to go slightly off, at least by the end of it, if it is linked to the video frames - I had forgotten about that, so I did nothing to the pre-made setting for the audio in the media management.
But to my suprise, the audio seems still perfectly aligned, I even compared between the original and the transcoded using a simple player (VLC), and at the same point in time, the same audio in both files.
So, the question is...
Is Da Vinci, at least in that specific kind of situation (changing the fps reducing them, but not the lenght of audio and video) when transcoding, automatically copying the audio maintaining the time information of where the audio goes as timecode/time, or even without having that information, just copy the audio "as is", rather than as correspondance to the frames ?
Considering also that the audio and video are in one container but are separate streams and with separate encodings, that would seem a technically sensible explanation (at least, as an IT person, that is how I would reach that result) of how the audio could seem to keep the sync with the time, despite the reduction in fps.
But before I transcode a bunch of files and discover much later that most of them have the audio out of sync because Studio tried to sync the audio to the frames, I woud like to have a clear answer from someone who knows it well.
Thanks in advance !
I got a kind of strange question, and yes, I looked at the manual before asking.
Situation: I got some files at least part of which I will probably even delete because I dont' think they are important, but for the time being, I am just trying to reduce the occupied space, especially for the bigger ones, while I wait to put the time aside to go through them and decide which ones to delete.
Many of the bigger ones turns out are already H264, but 29.97fps, someone must have thought about USA TV standards.
Since I have a full Studio license of Resolve for other purposes (so, why not use it ?), and since even without "batch transcoding" called this way, the media management ends up being usable to do basically the same, I was thinking to transcode them to H265 25fps with some optimisation, for me is good enough, and doing some test file, I saw the reduction in size was quite nice, e.g. ca 800MB on a 3.67GB file.
In configuring I touched only the video part, left the audio as it was.
I then tried to look at a file to check the quality, confirming with the original, and that at the resolution i was using to watch it (not even full screen), there was not visible difference (I set to keep the original resolution, no rescaling), and I realised I had forgotten something.
The audio is synced for 29.97fps, so in theory, taking out the 4.97 fps, even if the whole video is just some 45', one hour or so, the audio is supposed to go slightly off, at least by the end of it, if it is linked to the video frames - I had forgotten about that, so I did nothing to the pre-made setting for the audio in the media management.
But to my suprise, the audio seems still perfectly aligned, I even compared between the original and the transcoded using a simple player (VLC), and at the same point in time, the same audio in both files.
So, the question is...
Is Da Vinci, at least in that specific kind of situation (changing the fps reducing them, but not the lenght of audio and video) when transcoding, automatically copying the audio maintaining the time information of where the audio goes as timecode/time, or even without having that information, just copy the audio "as is", rather than as correspondance to the frames ?
Considering also that the audio and video are in one container but are separate streams and with separate encodings, that would seem a technically sensible explanation (at least, as an IT person, that is how I would reach that result) of how the audio could seem to keep the sync with the time, despite the reduction in fps.
But before I transcode a bunch of files and discover much later that most of them have the audio out of sync because Studio tried to sync the audio to the frames, I woud like to have a clear answer from someone who knows it well.
Thanks in advance !