Author Topic: SD Overclocking - DIGIC 5 only  (Read 9771 times)

Danne

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Re: SD Overclocking - DIGIC 5 only
« Reply #25 on: September 22, 2022, 07:53:31 AM »
If that's the only way, I will take that route then.
It is a different kind of endeavour, as I will need a second tripod, etc.
Most likely compression errors if text appear while recording. Check this place in mlv_lite.c:
Code: [Select]
        if (OUTPUT_COMPRESSION)
        {
            /* PackMem appears to require stricter memory alignment */
            ASSERT(((uint32_t)out_ptr & 0x3F) == 0);
            ASSERT((max_frame_size & 0xFFF) == 0);
            struct memSuite * outSuite = CreateMemorySuite(out_ptr, max_frame_size, 0);
            ASSERT(outSuite);

            int compressed_size = lossless_compress_raw_rectangle(
                outSuite, fullSizeBuffer,
                raw_info.width, (skip_x + 7) & ~7, skip_y & ~1,
                res_x, res_y
            );

            /* only report compression errors while recording
             * some of them appear during video mode switches
             * unlikely to cause actual trouble - silence them for now */
            if (compressed_size < 0 && !RAW_IS_IDLE)
            {
                printf("Compression error %d at frame %d\n", compressed_size, frame_count-1);
                ASSERT(0);
            }

            DeleteMemorySuite(outSuite);

gabriielangel

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Re: SD Overclocking - DIGIC 5 only
« Reply #26 on: September 22, 2022, 03:12:55 PM »
I did a quick record this morning. I will be able to tell you about the data rates of the different sections in the mlv file this evening.

In the video I start with a soft focus of my test image. I stop recording myself;
Second trial I focus a little more, It stops recording itself;
Third trial I get sharp focus. You see the errors (As Danne said, while recording) I let it go a little then stop recording.

Video Demonstration: https://bit.ly/3Uxkkcs

Test conditions to replicate easily:
2.5k 1:1 Preset
Lens at f3.5
Iso 400 (Makes it easier to replicate)
Lens at 66 cm from the screen
Exposure as seen on screen (It will still happen without the Overlays, I left those on for ease)
Record the still first frame of the test file (The rest is to test something else): https://bit.ly/3LwH4W9

This is not limited to Lab settings, I ran into this problem during the summer when shooting certain foliage and animal closeups (Fur) under harsh sun, but could not figure it out.

Danne

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Re: SD Overclocking - DIGIC 5 only
« Reply #27 on: September 23, 2022, 09:35:59 AM »
Compression errors can be fixed with tweaking regs. Often reg 713 and reg 7150. Seems this could be needed in this preset.

EDIT: Then again when looking closer I see liveview addons like histogram? If so, test is not valid. No extras to reduce overhead. Use only framing or real time previev, nothing else selected.
Generally when speed indicator goes in and out of orange red there could be a compression error risk.

gabriielangel

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Re: SD Overclocking - DIGIC 5 only
« Reply #28 on: September 23, 2022, 05:00:12 PM »
@Danne, if you read closely, I said that I left the overlays on for ease, because exposure is an important parameter (I specified, because we had an exchange about this).
I ran the test with and without the Histogram and spot meter, and it did it too. I am able to replicate the test results on demand.

I think that because it is easier to make it crap out 10 times out of 10 when ISO is set to 400, I suspect that the extra noise (Extra details) is one of the reasons.
But I could be wrong.

Edit: Do you know what reg_713c and reg_7150 Stand for? The values are -2000 to +2000. That's a lot of combinations to test :)

Danne

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Re: SD Overclocking - DIGIC 5 only
« Reply #29 on: September 23, 2022, 05:16:12 PM »
You can check in crop_rec.c. Unfortunately I can't help atm but you could try lowering 7150 a little and raise 713c or lower. No more than 5-15 up and down 713c.
7150 not sure if needed.

gabriielangel

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Re: SD Overclocking - DIGIC 5 only
« Reply #30 on: September 23, 2022, 08:39:03 PM »
This is within my capabilities, no problem.
Maybe someone in the know could chime in, if they have the explanation handy(Actual purpose of each reg, so I can take potential problems into consideration)?

BTW, for those reading this out of context, this problem can be mitigated by:

1-Using a lower ISO (Less noise to encode)
2-Underexposition (Which results in a larger number of darker patches, easier to encode)
3-Avoiding tiny little details across the frame. For example, if I need to film a medium shot with blowing tree leaves without a subject in the foreground (Blurs the background a bit), I use the soft lens.

When I run into this problem, it is often because I move the camera, and the reflexions I tamed with the polarizer reappear suddently because of the change of angle.

I will move any findings, if any, in your main thread, to keep this one less cluttered.