[HTC 10 Guides, News, & Discussion] l4n6u573:
For those who want to dig deeper optimising these plethora of options for gcam, this is an useful addition to build.prop:

persist.gcam.save_text=1

After rebooting gcam logs debug information in:

/storage/emulated/0/Android/data/com.google.android.GoogleCamera/cache/gcam/

For every picture taken you will find a folder containing these files:

init_params.txt

statistics.txt

payload_burst_actual.txt

summary.txt

shot_params.txt

time_log.txt

static_metadata.txt

unused_logging_metadata.txt

init_params.txt example:

InitParams

init_params_file_version 21

disable_smart_metering 0

min_full_metering_sweep_frames 3

max_full_metering_sweep_frames 6

min_payload_frames 3

max_payload_frames 28

max_zsl_frames 28

allow_unknown_devices 0

tuning_locked 1

thread_count 4

verbose 0

capture_pri.explicitly_set 0

capture_pri.value 9999

merge_pri.explicitly_set 1

merge_pri.value 8

finish_pri.explicitly_set 1

finish_pri.value 9

payload_frame_copy_mode never_copy

planning_to_process_bayer_for_metering 1

planning_to_process_bayer_for_payload 1

planning_to_provide_both_yuv_and_raw_for_metering 0

planning_to_provide_both_yuv_and_raw_for_payload 0

use_hexagon 1

simultaneous_merge_and_finish 1

summary.txt example:

Gcam version: 1.0.163413028

Build timestamp: Built on Jul 27 2017 17:30:07 (1501201807)

AE training fingerprint: 0xf14d1312

ZSL shot: Yes

Orig. payload aspect ratio: 1.333

Desired final aspect ratio: 1.333

Digital zoom: No (1.00x)

Smart Metering disabled: No

Weighted metering area count: 2

max_payload_frames: 28

Set zsl_rough_base_frame_index_ to 0.

Payload burst: 15 ZSL frames provided; 15 valid.

ZSL base frame candidate count: 3

Base frame index: 0

Base frame underexposure (post-raw gain): 1.00

Faces detected: No

base frame current TET: 929.091

base frame exposure time: 70.000 ms

base frame analog gain: 13.273

base frame digital gain: 1.000 (so far)

shot_min_tet: 929.091 (from base frame)

shot_max_tet: 6720.000 (from max_overall_gain)

AE results (from base frame):

scene_is_hdr = 1

run_hdr = 1

ideal HDR ratio = 3.32

final HDR ratio = 1.19

AE(single): conf -999.0, original tet 0.00, final tet 0.00

AE(short): conf 6.7, original tet 331.73, final tet 929.09

AE(long): conf 5.7, original tet 1102.95, final tet 1102.95

predicted_image_brightness: 113.8

log_scene_brightness: -2.32

fraction_of_pixels_from_long_exposure: 0.88

Further global digital gain of 1.000x will be applied.

short TET from AE had to be boosted by 180.1%; highlights in the final image will be over-exposed.

Finish will use 2 synthetic exposures.

Time-to-postview: 0.240 seconds.

Discarded (blurry) frame 9 out of 15 total frames (15 valid).

Discarded (blurry) frame 1 out of 15 total frames (14 valid).

Found 141040 potential hot pixels

WARNING: A large number of pixels (1.18%) were defective! The detection thresholds are likely poorly tuned. This can affect performance and image quality, and should be fixed.

Merge frame count: 13

Base frame SNR: 5.94433

Merging 13 frames of 4000 x 3000 resolution, tile size 16, gain 4

Merged frame SNR (estimate): 21.4326

Merged 13 frames.

Estimated black level adjustments: 0.891479 0.891479 0.891479 0.891479

Using Hexagon...

Finish will use 2 synthetic exposures.

WARNING: FinishRawHalide succeeded on Hexagon.

Success.