Video files' sizes rounded up to the nearest ~32MB (A7C II)

[PiotrKu]

Hi,

I asked that question somewhere else, but not response yet, so maybe here are some users who could help me resolve the issue.
Last year I switched from Nikon to Sony (A7Cm2) and after some time I got an unpleasant surprise.
When I travel, I record rather short 8-30s clips, a lot of such clips (>700).
and I found that these files are quite large as they are rounded up to the nearest ~32MB.
For this reason, SD cards (64GB) fill up very quickly.

Sample sizes for different durations of those clips (for example I have 700 clips with these "distinctive" sizes +/-) nothing in between
33.592.255
67.149.921
100.706.705
134.367.160
167.821.451
201.378.823
234.936.491
268.594.590
302.050.059
335.709.042
... and so on
+/-1000 for the smaller files up to +/-100.000 for the bigger ones rounded up to the nearest ~32MB
Different SD cards 64GB were formatted inside the camera with exFAT (allocation unit size is 128KB)

Why is that?
Is there some setting for that? I tried different video formats in the camera, but there was no difference.
Would it be helpful to use a different allocation unit size when formatting (outside the camera) or is this just a "feature, not a bug"?

---
Piotr

 

[UncleVanya]

Hi,
I asked that question somewhere else, but not response yet, so maybe here are some users who could help me resolve the issue.
Last year I switched from Nikon to Sony (A7Cm2) and after some time I got an unpleasant surprise.
When I travel, I record rather short 8-30s clips, a lot of such clips (>700).
and I found that these files are quite large as they are rounded up to the nearest ~32MB.
For this reason, SD cards (64GB) fill up very quickly.

Were you using the same size card in the Nikon? FAT32 maxed out at 32gb. ExFAT has a 128kb allocation unit typically but you can verify this by following the instructions here: https://www.easeus.com/amp/computer-instruction/allocation-unit-size-for-sd-card.html

32mb seems nuts however.

 

[sludge21017]

Honestly, get a larger card?



Prograde V60 if that's all you need. The V90 usually comes on sale, but is still around $180US.



Here's a random sample from my ZV-E1, because I this has happened in the past before I saw your post, so I couldn't have tried one way or the other to manufacturer the problem or not... I do have a few that "match".



256GB card.

 

[PiotrKu]

Were you using the same size card in the Nikon?

32mb seems nuts however.

Sony of course, I just wrote that I switched from Nikon.
Cards 64GB were brand new, formatted in the camera body, and I've already checked the alloc size , which is 128

 

[PiotrKu]

Honestly, get a larger card?

When I switched system to Sony I had no experience with shooting with the new Sony camera yet and at that time I bought 4 x 64GB V90. I just wasn't expecting that kind of issue.
For years with Nikon I've never seen that kind of handling of video files' sizes and I decided not to for 128 or bigger, because that camera body has only 1 card slot. I prefer not having all my materials on one card (despite I'm making backups on one big SD card every evening during my trips)

So now it seems I have to buy again all my cards, but this time just bigger, damn it.

On your card I can see a similar situation with file sizes. Maybe it's more consistence, but still similar.

 

[UncleVanya]

Were you using the same size card in the Nikon?

32mb seems nuts however.

Sony of course, I just wrote that I switched from Nikon.
Cards 64GB were brand new, formatted in the camera body, and I've already checked the alloc size , which is 128

You misunderstood part of my question. I was asking if the same size card was used in the Nikon on the past resulting in different file size behavior. What codec was used in the Nikon previously and what size sensor etc. Knowing that level of detail may help. Did the Nikon crop video? Are we talking apples to apples.

 

[panther fan]

Hi,
I asked that question somewhere else, but not response yet, so maybe here are some users who could help me resolve the issue.
Last year I switched from Nikon to Sony (A7Cm2) and after some time I got an unpleasant surprise.
When I travel, I record rather short 8-30s clips, a lot of such clips (>700).
and I found that these files are quite large as they are rounded up to the nearest ~32MB.
For this reason, SD cards (64GB) fill up very quickly.

I understand your frustration and this seems like an artifiial conter size choice by Sony.

That said, it seem the cards are to small to begin with. If we assume random size distribution, you waste on average around 16MB per file. Even with 700 files that is "just" 11GB. Or 17% of capacity (if you really want to record 700 clips to one card)

But even 8s clips should incur an even lower penalty at 200Mbps, as they are already 200MB in size, with then just a 16MB penalty (so 8%) and even less for longer clips.

If you tried out all recording modes, PAL/NTSC, long-gop and all-I, then I don't think there is another solution to this

Loading…

helpguide.sony.net

 

[PiotrKu]

You misunderstood part of my question. I was asking if the same size card was used in the Nikon on the past resulting in different file size behavior. What codec was used in the Nikon previously and what size sensor etc. Knowing that level of detail may help. Did the Nikon crop video? Are we talking apples to apples.

No, for Sony camera cards were brand new with higher speed and bigger capacity.
In the Nikon H264 codec was used. Sensor APSC 24Mpix. And no crop.

 

[PiotrKu]

That said, it seem the cards are to small to begin with. If we assume random size distribution, you waste on average around 16MB per file. Even with 700 files that is "just" 11GB. Or 17% of capacity (if you really want to record 700 clips to one card)

But even 8s clips should incur an even lower penalty at 200Mbps, as they are already 200MB in size, with then just a 16MB penalty (so 8%) and even less for longer clips.

If you tried out all recording modes, PAL/NTSC, long-gop and all-I, then I don't think there is another solution to this

Yea, I'm aware of the size penalty with smaller files.
I tried different things, but still the same result. So it seems it is like it is and I have to deal with it and I need to buy bigger cards.

I'm very IT guy (heavy coding for 30 years) and and I can *guess* why they did it that way (if that was intended) for writing efficiency, ...yea I hope it was intended by Sony software developers team.

 

[panther fan]

That said, it seem the cards are to small to begin with. If we assume random size distribution, you waste on average around 16MB per file. Even with 700 files that is "just" 11GB. Or 17% of capacity (if you really want to record 700 clips to one card)

But even 8s clips should incur an even lower penalty at 200Mbps, as they are already 200MB in size, with then just a 16MB penalty (so 8%) and even less for longer clips.

If you tried out all recording modes, PAL/NTSC, long-gop and all-I, then I don't think there is another solution to this

Yea, I'm aware of the size penalty with smaller files.
I tried different things, but still the same result. So it seems it is like it is and I have to deal with it and I need to buy bigger cards.

I'm very IT guy (heavy coding for 30 years) and and I can *guess* why they did it that way (if that was intended) for writing efficiency, ...yea I hope it was intended by Sony software developers team.

Sony uncompressed RAW Format is a 16bit format despite all their cameras having only 14bit read modes

I don't think they worry too much about space efficiency

 

[PiotrKu]

I don't think they worry too much about space efficiency

I agree. They care most about writing speed, not space optimization.

 

[dazzerfong]

That said, it seem the cards are to small to begin with. If we assume random size distribution, you waste on average around 16MB per file. Even with 700 files that is "just" 11GB. Or 17% of capacity (if you really want to record 700 clips to one card)

But even 8s clips should incur an even lower penalty at 200Mbps, as they are already 200MB in size, with then just a 16MB penalty (so 8%) and even less for longer clips.

If you tried out all recording modes, PAL/NTSC, long-gop and all-I, then I don't think there is another solution to this

Yea, I'm aware of the size penalty with smaller files.
I tried different things, but still the same result. So it seems it is like it is and I have to deal with it and I need to buy bigger cards.

I'm very IT guy (heavy coding for 30 years) and and I can *guess* why they did it that way (if that was intended) for writing efficiency, ...yea I hope it was intended by Sony software developers team.

Sony uncompressed RAW Format is a 16bit format despite all their cameras having only 14bit read modes

I don't think they worry too much about space efficiency

Yeah it's pretty ancient. If it were just 6000x4000 (actually 6048x4024) @ 16 bits each uncompressed it'll be around 46MB for just the raw data, which lines up very closely to around 50MB per raw file. Reading 16 bits is faster and easier than interpreting 14 bits amongst 2 bytes and truncating for the next pixel, so I get why they did that.

Luckily lossless compression deals with these repeating points very effectively as the two LSBs are going to be zeroes.

 

[panther fan]

That said, it seem the cards are to small to begin with. If we assume random size distribution, you waste on average around 16MB per file. Even with 700 files that is "just" 11GB. Or 17% of capacity (if you really want to record 700 clips to one card)

But even 8s clips should incur an even lower penalty at 200Mbps, as they are already 200MB in size, with then just a 16MB penalty (so 8%) and even less for longer clips.

If you tried out all recording modes, PAL/NTSC, long-gop and all-I, then I don't think there is another solution to this

Yea, I'm aware of the size penalty with smaller files.
I tried different things, but still the same result. So it seems it is like it is and I have to deal with it and I need to buy bigger cards.

I'm very IT guy (heavy coding for 30 years) and and I can *guess* why they did it that way (if that was intended) for writing efficiency, ...yea I hope it was intended by Sony software developers team.

Sony uncompressed RAW Format is a 16bit format despite all their cameras having only 14bit read modes

I don't think they worry too much about space efficiency

Yeah it's pretty ancient. If it were just 6000x4000 (actually 6048x4024) @ 16 bits each uncompressed it'll be around 46MB for just the raw data, which lines up very closely to around 50MB per raw file. Reading 16 bits is faster and easier than interpreting 14 bits amongst 2 bytes and truncating for the next pixel, so I get why they did that.

Sony RAW files also contain a full res JPEG after the second or third generation of cameras, which explains the delta

Luckily lossless compression deals with these repeating points very effectively as the two LSBs are going to be zeroes.

Yes lossless compression with the fifth gen cameras was a good step forward

 

[pollup]

Hi,
I asked that question somewhere else, but not response yet, so maybe here are some users who could help me resolve the issue.
Last year I switched from Nikon to Sony (A7Cm2) and after some time I got an unpleasant surprise.
When I travel, I record rather short 8-30s clips, a lot of such clips (>700).
and I found that these files are quite large as they are rounded up to the nearest ~32MB.
For this reason, SD cards (64GB) fill up very quickly.

Sample sizes for different durations of those clips (for example I have 700 clips with these "distinctive" sizes +/-) nothing in between
33.592.255
67.149.921
100.706.705
134.367.160
167.821.451
201.378.823
234.936.491
268.594.590
302.050.059
335.709.042
... and so on
+/-1000 for the smaller files up to +/-100.000 for the bigger ones rounded up to the nearest ~32MB
Different SD cards 64GB were formatted inside the camera with exFAT (allocation unit size is 128KB)

Why is that?
Is there some setting for that? I tried different video formats in the camera, but there was no difference.
Would it be helpful to use a different allocation unit size when formatting (outside the camera) or is this just a "feature, not a bug"?
---
Piotr

Reason is a programming one:

1) it's good to reserve space ahead of recording, and do the minimum number of space allocations, for performance reasons, so 32MB chunks is rather optimal.

2) so it means that 32MB was reserved on the card and now the camera can start writing to this space, and when it's about to reach 32MB, it will reserve 32 extra MB and so on.

3) however, when the recording is finished, the camera should then trim the unused space at the end, and I guess that's the step that Sony forgot to execute, and that's why you're left with extra padding in the files.