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Thumbnail offset not respected on all videos

#1
Question 
Hello, I have a folder with mostly mp4 videos, and I have set the "Thumbnail offset" setting to 50%, assuming that this will create the thumbnail from the middle of the video.
On some video files, that is indeed the case, but on most it is not. I thought that this may have to do with the codecs used, but they all seem to have the same codec:


Codec ID: isom (isom/iso2/avc1/mp41)
Format: AVC
Format/Info: CABAC / 4 Ref Frames

What goes?

Thanks for the awesome work by the way!  Smile
Reply

#2
(10-07-2020, 08:14 AM)AsGoodAsltGets Wrote: Hello, I have a folder with mostly mp4 videos, and I have set the "Thumbnail offset" setting to 50%, assuming that this will create the thumbnail from the middle of the video.
On some video files, that is indeed the case, but on most it is not. I thought that this may have to do with the codecs used, but they all seem to have the same codec:


Codec ID: isom (isom/iso2/avc1/mp41)
Format: AVC
Format/Info: CABAC / 4 Ref Frames

What goes?

Thanks for the awesome work by the way!  Smile

If you have "Enable black/white frame detection" set, that could cause Icaros to go further into the video to find a more viable frame, if the first one it finds, is either very dark or light.

When using the "Thumbnail offset" option, Icaros also uses the default ffmpeg seeking, which usually seeks to the nearest keyframe around the estimated timestamp.
Depending on the container used (MP4/MKV/AVI etc), and whether or not the file has an index, it varies greatly how accurate the seeking will be, but with most modern containers,
it's usually quite close to original timestamp.

If you use the "Prefer Timestamp" option, the returned thumbnail will be more accurately fetched, but this can in some cases slow down the thumbnailing speed of Icaros.
Of course, prefer timestamp also doesn't allow you to seek to a specific percentage in the movie, so there's that.

That said, disabling "black/white frame detection" should be enough for most users, looking for more accurate seeking based on the offset.
Reply

#3
(10-11-2020, 03:53 PM)Xanashi Wrote:
(10-07-2020, 08:14 AM)AsGoodAsltGets Wrote: Hello, I have a folder with mostly mp4 videos, and I have set the "Thumbnail offset" setting to 50%, assuming that this will create the thumbnail from the middle of the video.
On some video files, that is indeed the case, but on most it is not. I thought that this may have to do with the codecs used, but they all seem to have the same codec:


Codec ID: isom (isom/iso2/avc1/mp41)
Format: AVC
Format/Info: CABAC / 4 Ref Frames

What goes?

Thanks for the awesome work by the way!  Smile

If you have "Enable black/white frame detection" set, that could cause Icaros to go further into the video to find a more viable frame, if the first one it finds, is either very dark or light.

When using the "Thumbnail offset" option, Icaros also uses the default ffmpeg seeking, which usually seeks to the nearest keyframe around the estimated timestamp.
Depending on the container used (MP4/MKV/AVI etc), and whether or not the file has an index, it varies greatly how accurate the seeking will be, but with most modern containers,
it's usually quite close to original timestamp.

If you use the "Prefer Timestamp" option, the returned thumbnail will be more accurately fetched, but this can in some cases slow down the thumbnailing speed of Icaros.
Of course, prefer timestamp also doesn't allow you to seek to a specific percentage in the movie, so there's that.

That said, disabling "black/white frame detection" should be enough for most users, looking for more accurate seeking based on the offset.

Hi, thank you for your reply, but unfortunately, none of the settings seem to have any effect. It seems like the thumbnails are actually generated by Windows/Explorer or are cached somewhere other than the Icaros cache location (I tried emptying the Icaros cache and rebuilding them multiple times, no effect).
And it's not like the offset is not exactly at 50%. Most of the time is near the start, 0 or 1%, instead of whatever else I choose.
And I made sure the folder is added in the cache locations. I even tried moving some files to another location, and the thumbnails persist.

(10-12-2020, 11:29 AM)AsGoodAsltGets Wrote:
(10-11-2020, 03:53 PM)Xanashi Wrote:
(10-07-2020, 08:14 AM)AsGoodAsltGets Wrote: Hello, I have a folder with mostly mp4 videos, and I have set the "Thumbnail offset" setting to 50%, assuming that this will create the thumbnail from the middle of the video.
On some video files, that is indeed the case, but on most it is not. I thought that this may have to do with the codecs used, but they all seem to have the same codec:


Codec ID: isom (isom/iso2/avc1/mp41)
Format: AVC
Format/Info: CABAC / 4 Ref Frames

What goes?

Thanks for the awesome work by the way!  Smile

If you have "Enable black/white frame detection" set, that could cause Icaros to go further into the video to find a more viable frame, if the first one it finds, is either very dark or light.

When using the "Thumbnail offset" option, Icaros also uses the default ffmpeg seeking, which usually seeks to the nearest keyframe around the estimated timestamp.
Depending on the container used (MP4/MKV/AVI etc), and whether or not the file has an index, it varies greatly how accurate the seeking will be, but with most modern containers,
it's usually quite close to original timestamp.

If you use the "Prefer Timestamp" option, the returned thumbnail will be more accurately fetched, but this can in some cases slow down the thumbnailing speed of Icaros.
Of course, prefer timestamp also doesn't allow you to seek to a specific percentage in the movie, so there's that.

That said, disabling "black/white frame detection" should be enough for most users, looking for more accurate seeking based on the offset.

Hi, thank you for your reply, but unfortunately, none of the settings seem to have any effect. It seems like the thumbnails are actually generated by Windows/Explorer or are cached somewhere other than the Icaros cache location (I tried emptying the Icaros cache and rebuilding them multiple times, no effect).
And it's not like the offset is not exactly at 50%. Most of the time is near the start, 0 or 1%, instead of whatever else I choose.
And I made sure the folder is added in the cache locations. I even tried moving some files to another location, and the thumbnails persist.

Ok, never mind, I had to clear the Windows thumbnail cache to make it rebuild everything from scratch and now everything works fine Smile
Reply

#4
(10-12-2020, 11:29 AM)AsGoodAsltGets Wrote:
(10-11-2020, 03:53 PM)Xanashi Wrote:
(10-07-2020, 08:14 AM)AsGoodAsltGets Wrote: Hello, I have a folder with mostly mp4 videos, and I have set the "Thumbnail offset" setting to 50%, assuming that this will create the thumbnail from the middle of the video.
On some video files, that is indeed the case, but on most it is not. I thought that this may have to do with the codecs used, but they all seem to have the same codec:


Codec ID: isom (isom/iso2/avc1/mp41)
Format: AVC
Format/Info: CABAC / 4 Ref Frames

What goes?

Thanks for the awesome work by the way!  Smile

If you have "Enable black/white frame detection" set, that could cause Icaros to go further into the video to find a more viable frame, if the first one it finds, is either very dark or light.

When using the "Thumbnail offset" option, Icaros also uses the default ffmpeg seeking, which usually seeks to the nearest keyframe around the estimated timestamp.
Depending on the container used (MP4/MKV/AVI etc), and whether or not the file has an index, it varies greatly how accurate the seeking will be, but with most modern containers,
it's usually quite close to original timestamp.

If you use the "Prefer Timestamp" option, the returned thumbnail will be more accurately fetched, but this can in some cases slow down the thumbnailing speed of Icaros.
Of course, prefer timestamp also doesn't allow you to seek to a specific percentage in the movie, so there's that.

That said, disabling "black/white frame detection" should be enough for most users, looking for more accurate seeking based on the offset.

Hi, thank you for your reply, but unfortunately, none of the settings seem to have any effect. It seems like the thumbnails are actually generated by Windows/Explorer or are cached somewhere other than the Icaros cache location (I tried emptying the Icaros cache and rebuilding them multiple times, no effect).
And it's not like the offset is not exactly at 50%. Most of the time is near the start, 0 or 1%, instead of whatever else I choose.
And I made sure the folder is added in the cache locations. I even tried moving some files to another location, and the thumbnails persist.

(10-12-2020, 11:29 AM)AsGoodAsltGets Wrote:
(10-11-2020, 03:53 PM)Xanashi Wrote:
(10-07-2020, 08:14 AM)AsGoodAsltGets Wrote: Hello, I have a folder with mostly mp4 videos, and I have set the "Thumbnail offset" setting to 50%, assuming that this will create the thumbnail from the middle of the video.
On some video files, that is indeed the case, but on most it is not. I thought that this may have to do with the codecs used, but they all seem to have the same codec:


Codec ID: isom (isom/iso2/avc1/mp41)
Format: AVC
Format/Info: CABAC / 4 Ref Frames

What goes?

Thanks for the awesome work by the way!  Smile

If you have "Enable black/white frame detection" set, that could cause Icaros to go further into the video to find a more viable frame, if the first one it finds, is either very dark or light.

When using the "Thumbnail offset" option, Icaros also uses the default ffmpeg seeking, which usually seeks to the nearest keyframe around the estimated timestamp.
Depending on the container used (MP4/MKV/AVI etc), and whether or not the file has an index, it varies greatly how accurate the seeking will be, but with most modern containers,
it's usually quite close to original timestamp.

If you use the "Prefer Timestamp" option, the returned thumbnail will be more accurately fetched, but this can in some cases slow down the thumbnailing speed of Icaros.
Of course, prefer timestamp also doesn't allow you to seek to a specific percentage in the movie, so there's that.

That said, disabling "black/white frame detection" should be enough for most users, looking for more accurate seeking based on the offset.

Hi, thank you for your reply, but unfortunately, none of the settings seem to have any effect. It seems like the thumbnails are actually generated by Windows/Explorer or are cached somewhere other than the Icaros cache location (I tried emptying the Icaros cache and rebuilding them multiple times, no effect).
And it's not like the offset is not exactly at 50%. Most of the time is near the start, 0 or 1%, instead of whatever else I choose.
And I made sure the folder is added in the cache locations. I even tried moving some files to another location, and the thumbnails persist.

Ok, never mind, I had to clear the Windows thumbnail cache to make it rebuild everything from scratch and now everything works fine Smile

Icaros cannot clear the cache. If you want new thumbnails, you must clear the Windows cache using the Disk Cleanup utility.
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