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Official GX1 hack development topic
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  • skuazskuaz

    Thank you Vitaliy and your team for your awesome, awesome work. Next paycheck I'll make sure to send more money your way.

    A question for you hackers: from what you have written, it seems like the sensor can output both 25fps and 30fps depending on NTCS/PAL settings. Does this mean that the sensor's framerate can be set via firmware? What about 60p? Is that actually possible?

    In anycase, looking forward to your hack.

    Thank you again, J.

  • Tbo711Tbo711

    Yes, thank you Vitaliy for your great efforts. Can't wait to unleash the GX1.

  • MicahMicah

    Thank you for the excellent results of your hard work Vitaliy!

  • driftwooddriftwood

    Thats true.

  • Vitaliy_KiselevVitaliy_Kiselev

    @driftwood

    Yep, bitrate is set at 10Mbit, but bit_rate_value_minus1 and cpb_size_value_minus1 do not match. Same for 1080 MP4 modes (as they are more approariate for 22-23Mbit.).

  • driftwooddriftwood

    Hmmm... Judging by the charts above they set up rate control with a target of around 10Mbit.

  • Vitaliy_KiselevVitaliy_Kiselev

    Bitrate readings - Stock Settings PAL 25p MP4

    Yep, if you look, they are higher than 1080p24 settings (with formally higher bitrate) :-)

    Even more difference is in 720p MP4, as they are higher than settings for 16Mbit modes :-)

    I absolutely do not get why this 10Mbit is used.

  • driftwooddriftwood

    Current info about the GX1 mp4 mode;-

    Bitrate readings - Stock Settings PAL 25p MP4

    • bit_rate_value_minus1 = 23436 (they say approx 20M)
    • cpb_size_value_minus1 = 16405 (16M buffer)

    Other info:

    • num_ref_frames = 2
    • GOP 12/15 for 1080 25p/30p (i and p frames only allowed - conformance to baseline 66 std)
    • Seemingly different frame limits for each of the 25p/30p mp4 modes from VKs ptools pic - nice! AVC profile = 66 (Baseline) - info about this profile - http://www.digitalpreservation.gov/formats/fdd/fdd000225.shtml

    MPEG-4, Advanced Video Coding, Baseline Profile Description:

    Baseline is the least complex of the three original MPEG-4_AVC profiles (Baseline, Main, and Extended), i.e., it places the least demand on a decoder. The Baseline Profile is constrained in several ways, including a limit to intra (I) and predicted (P) slice types (slice is the MPEG-4_AVC term for a single macroblock or a set of macroblocks that make up a portion of an individual picture.) For a discussion of additional contraints and the levels that may be used in this profile, see Appendix A in Part 10 of the standard, pp. 204-211.

    The Part 10 Standard: http://www.iitk.ac.in/mwn/vaibhav/Vaibhav%20Sharma_files/h.264_standard_document.pdf

    * Sensor:

    MP4: NTSC

    • [Full HD] 1920 x 1080, 30fps (sensor output is 30p) (Approx.20Mbps).

    • [HD] 1280 x 720, 30fps (sensor output is 30p) (Approx.10Mbps)

    MP4: PAL

    • [Full HD] 1920 x 1080, 25fps (sensor output is 25p) (Approx.20Mbps)

    • [HD] 1280 x 720, 25fps (sensor output is 25p) (Approx.10Mbps)

    AVCHD: NTSC

    • [Full HD] 1920×1080, 60i (sensor output is 30p) (FSH:17Mbps) / [HD] 1280 x 720, 60p (sensor output is 30p)（SH:17Mbps)

    AVCHD: PAL

    • [Full HD] 1920×1080, 50i (sensor output is 25p) (FSH:17Mbps) / [HD] 1280 x 720, 50p (sensor output is 25p)（SH:17Mbps)
    gx1_mp4_mode_1080p25_progressive_12 GOP.png
    1412 x 902 - 639K
    GX1 720p25HD mode.png
    1550 x 717 - 956K
    GX1 Stock 720p25HD on a death chart - buffer analysis.png
    720 x 787 - 37K
  • gamebgameb

    What about the image quality?

  • driftwooddriftwood

    mp4 wrapper is conversely more supported on pcs, devices etc... than avchd. Pany sells it as 'instantly stick your vids up on the web...!'

  • stoneystoney

    Is there any MP4 advantage over AVCHD other than some tablets can edit MP4 files?

  • Vitaliy_KiselevVitaliy_Kiselev

    Thanks guys.

    GX1 is complicated. Due to MP4 and some changed code.

  • stoneystoney

    Nice. I just upgraded to GX1. Hehe.

  • driftwooddriftwood

    That a very welcoming ptools picture @Vitaliy_Kiselev :-) Congrats on your hard work.

  • bothabotha

    Congratulations Vitaliy, it looks absolutely amazing ! Last week i bought the G3 just because of your upcoming genius hack !!!

  • SumiSumi

    Awesome! Hope you're doing good (healthwise)!

  • JOFOJOFO

    wonderful... hope to see the same for G3 at the same time as GX1-G3 is one project :) keep up the good work VK!

  • bobwbobw

    Marvelous VK!! look forward to the release soon :)

  • Vitaliy_KiselevVitaliy_Kiselev

    image

    PTool, work in progress.
    Various MP4 specific modes settings are being added.

    ptool.jpg
    382 x 630 - 70K
  • stoneystoney

    Hope you feel better soon. I hate being sick.

  • PluttipluttPluttiplutt

    Take care VK. Hope you soon ok again.

  • skuazskuaz

    Well said lolodigital! +1!

  • lolodigitallolodigital

    Take care. Priority to health, family and friends. ptool can wait :-)

  • bobwbobw

    Good news to end June :) & good health for VK

  • scipioscipio

    Really a good news Vitaliy_Kiselev :) Sorry for your disease. I hope nothing of serious.

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