How to divide or cut a YUV file? - yuv

I have a YUV file with 150 frames, I want to divide it into 2 files of 75 frames each. How to go bu doing this ? Are there any software's to do this ?

No specific SW is needed. All you need to do is read/write the number of bytes that corresponds to a frame into a new file. "Normally" the YCbCr format used is subsampled according to 4:2:0, i.e. the chroma samples are reduced by a factor of 2 both horizontally and vertically; meaning that 1 frame in YCbCr 4:2:0 corresponds to
1 frame = width x height x 3 / 2 bytes
If you are on a linux based system, you can use the dd utility to extract the first n-frames into a new file like this:
dd if=input.yuv bs=1 count=$((width*height*3/2*num_frames)) of=output.yuv
for the first 10 frames of a 1080p clip, the above would be:
dd if=input.yuv bs=1 count=$((1920*1080*3/2*10)) of=output.yuv
or
dd if=input.yuv bs=1 count=3110400 of=output.yuv
or use your favorite programming/scripting language to do this.
For example, the following python-scripts writes the first 10 frames to a new file (one frame at a time), tweek it to your needs:
#!/usr/bin/env python
f_in = 'BQMall_832x480_60.yuv'
f_out = 'BQMall_first_10_frames.yuv'
f_size = 832*480*3/2
with open(f_in, 'rb') as fd_in, open(f_out, 'wb') as fd_out:
for i in range(10):
data = fd_in.read(f_size)
fd_out.write(data)

I suggest that "do not use bs = 1"
dd if=176x144.yuv bs= $((176 * 144 * 3 / 2)) count=$FrameNo of=output.yuv

Related

Encoding Spotify URI to Spotify Codes

Spotify Codes are little barcodes that allow you to share songs, artists, users, playlists, etc.
They encode information in the different heights of the "bars". There are 8 discrete heights that the 23 bars can be, which means 8^23 different possible barcodes.
Spotify generates barcodes based on their URI schema. This URI spotify:playlist:37i9dQZF1DXcBWIGoYBM5M gets mapped to this barcode:
The URI has a lot more information (62^22) in it than the code. How would you map the URI to the barcode? It seems like you can't simply encode the URI directly. For more background, see my "answer" to this question: https://stackoverflow.com/a/62120952/10703868
The patent explains the general process, this is what I have found.
This is a more recent patent
When using the Spotify code generator the website makes a request to https://scannables.scdn.co/uri/plain/[format]/[background-color-in-hex]/[code-color-in-text]/[size]/[spotify-URI].
Using Burp Suite, when scanning a code through Spotify the app sends a request to Spotify's API: https://spclient.wg.spotify.com/scannable-id/id/[CODE]?format=json where [CODE] is the media reference that you were looking for. This request can be made through python but only with the [TOKEN] that was generated through the app as this is the only way to get the correct scope. The app token expires in about half an hour.
import requests
head={
"X-Client-Id": "58bd3c95768941ea9eb4350aaa033eb3",
"Accept-Encoding": "gzip, deflate",
"Connection": "close",
"App-Platform": "iOS",
"Accept": "*/*",
"User-Agent": "Spotify/8.5.68 iOS/13.4 (iPhone9,3)",
"Accept-Language": "en",
"Authorization": "Bearer [TOKEN]",
"Spotify-App-Version": "8.5.68"}
response = requests.get('https://spclient.wg.spotify.com:443/scannable-id/id/26560102031?format=json', headers=head)
print(response)
print(response.json())
Which returns:
<Response [200]>
{'target': 'spotify:playlist:37i9dQZF1DXcBWIGoYBM5M'}
So 26560102031 is the media reference for your playlist.
The patent states that the code is first detected and then possibly converted into 63 bits using a Gray table. For example 361354354471425226605 is encoded into 010 101 001 010 111 110 010 111 110 110 100 001 110 011 111 011 011 101 101 000 111.
However the code sent to the API is 6875667268, I'm unsure how the media reference is generated but this is the number used in the lookup table.
The reference contains the integers 0-9 compared to the gray table of 0-7 implying that an algorithm using normal binary has been used. The patent talks about using a convolutional code and then the Viterbi algorithm for error correction, so this may be the output from that. Something that is impossible to recreate whithout the states I believe. However I'd be interested if you can interpret the patent any better.
This media reference is 10 digits however others have 11 or 12.
Here are two more examples of the raw distances, the gray table binary and then the media reference:
1.
022673352171662032460
000 011 011 101 100 010 010 111 011 001 100 001 101 101 011 000 010 011 110 101 000
67775490487
2.
574146602473467556050
111 100 110 001 110 101 101 000 011 110 100 010 110 101 100 111 111 101 000 111 000
57639171874
edit:
Some extra info:
There are some posts online describing how you can encode any text such as spotify:playlist:HelloWorld into a code however this no longer works.
I also discovered through the proxy that you can use the domain to fetch the album art of a track above the code. This suggests a closer integration of Spotify's API and this scannables url than previously thought. As it not only stores the URIs and their codes but can also validate URIs and return updated album art.
https://scannables.scdn.co/uri/800/spotify%3Atrack%3A0J8oh5MAMyUPRIgflnjwmB
Your suspicion was correct - they're using a lookup table. For all of the fun technical details, the relevant patent is available here: https://data.epo.org/publication-server/rest/v1.0/publication-dates/20190220/patents/EP3444755NWA1/document.pdf
Very interesting discussion. Always been attracted to barcodes so I had to take a look. I did some analysis of the barcodes alone (didn't access the API for the media refs) and think I have the basic encoding process figured out. However, based on the two examples above, I'm not convinced I have the mapping from media ref to 37-bit vector correct (i.e. it works in case 2 but not case 1). At any rate, if you have a few more pairs, that last part should be simple to work out. Let me know.
For those who want to figure this out, don't read the spoilers below!
It turns out that the basic process outlined in the patent is correct, but lacking in details. I'll summarize below using the example above. I actually analyzed this in reverse which is why I think the code description is basically correct except for step (1), i.e. I generated 45 barcodes and all of them matched had this code.
1. Map the media reference as integer to 37 bit vector.
Something like write number in base 2, with lowest significant bit
on the left and zero-padding on right if necessary.
57639171874 -> 0100010011101111111100011101011010110
2. Calculate CRC-8-CCITT, i.e. generator x^8 + x^2 + x + 1
The following steps are needed to calculate the 8 CRC bits:
Pad with 3 bits on the right:
01000100 11101111 11110001 11010110 10110000
Reverse bytes:
00100010 11110111 10001111 01101011 00001101
Calculate CRC as normal (highest order degree on the left):
-> 11001100
Reverse CRC:
-> 00110011
Invert check:
-> 11001100
Finally append to step 1 result:
01000100 11101111 11110001 11010110 10110110 01100
3. Convolutionally encode the 45 bits using the common generator
polynomials (1011011, 1111001) in binary with puncture pattern
110110 (or 101, 110 on each stream). The result of step 2 is
encoded using tail-biting, meaning we begin the shift register
in the state of the last 6 bits of the 45 long input vector.
Prepend stream with last 6 bits of data:
001100 01000100 11101111 11110001 11010110 10110110 01100
Encode using first generator:
(a) 100011100111110100110011110100000010001001011
Encode using 2nd generator:
(b) 110011100010110110110100101101011100110011011
Interleave bits (abab...):
11010000111111000010111011110011010011110001...
1010111001110001000101011000010110000111001111
Puncture every third bit:
111000111100101111101110111001011100110000100100011100110011
4. Permute data by choosing indices 0, 7, 14, 21, 28, 35, 42, 49,
56, 3, 10..., i.e. incrementing 7 modulo 60. (Note: unpermute by
incrementing 43 mod 60).
The encoded sequence after permuting is
111100110001110101101000011110010110101100111111101000111000
5. The final step is to map back to bar lengths 0 to 7 using the
gray map (000,001,011,010,110,111,101,100). This gives the 20 bar
encoding. As noted before, add three bars: short one on each end
and a long one in the middle.
UPDATE: I've added a barcode (levels) decoder (assuming no errors) and an alternate encoder that follows the description above rather than the equivalent linear algebra method. Hopefully that is a bit more clear.
UPDATE 2: Got rid of most of the hard-coded arrays to illustrate how they are generated.
The linear algebra method defines the linear transformation (spotify_generator) and mask to map the 37 bit input into the 60 bit convolutionally encoded data. The mask is result of the 8-bit inverted CRC being convolutionally encoded. The spotify_generator is a 37x60 matrix that implements the product of generators for the CRC (a 37x45 matrix) and convolutional codes (a 45x60 matrix). You can create the generator matrix from an encoding function by applying the function to each row of an appropriate size generator matrix. For example, a CRC function that add 8 bits to each 37 bit data vector applied to each row of a 37x37 identity matrix.
import numpy as np
import crccheck
# Utils for conversion between int, array of binary
# and array of bytes (as ints)
def int_to_bin(num, length, endian):
if endian == 'l':
return [num >> i & 1 for i in range(0, length)]
elif endian == 'b':
return [num >> i & 1 for i in range(length-1, -1, -1)]
def bin_to_int(bin,length):
return int("".join([str(bin[i]) for i in range(length-1,-1,-1)]),2)
def bin_to_bytes(bin, length):
b = bin[0:length] + [0] * (-length % 8)
return [(b[i]<<7) + (b[i+1]<<6) + (b[i+2]<<5) + (b[i+3]<<4) +
(b[i+4]<<3) + (b[i+5]<<2) + (b[i+6]<<1) + b[i+7] for i in range(0,len(b),8)]
# Return the circular right shift of an array by 'n' positions
def shift_right(arr, n):
return arr[-n % len(arr):len(arr):] + arr[0:-n % len(arr)]
gray_code = [0,1,3,2,7,6,4,5]
gray_code_inv = [[0,0,0],[0,0,1],[0,1,1],[0,1,0],
[1,1,0],[1,1,1],[1,0,1],[1,0,0]]
# CRC using Rocksoft model:
# NOTE: this is not quite any of their predefined CRC's
# 8: number of check bits (degree of poly)
# 0x7: representation of poly without high term (x^8+x^2+x+1)
# 0x0: initial fill of register
# True: byte reverse data
# True: byte reverse check
# 0xff: Mask check (i.e. invert)
spotify_crc = crccheck.crc.Crc(8, 0x7, 0x0, True, True, 0xff)
def calc_spotify_crc(bin37):
bytes = bin_to_bytes(bin37, 37)
return int_to_bin(spotify_crc.calc(bytes), 8, 'b')
def check_spotify_crc(bin45):
data = bin_to_bytes(bin45,37)
return spotify_crc.calc(data) == bin_to_bytes(bin45[37:], 8)[0]
# Simple convolutional encoder
def encode_cc(dat):
gen1 = [1,0,1,1,0,1,1]
gen2 = [1,1,1,1,0,0,1]
punct = [1,1,0]
dat_pad = dat[-6:] + dat # 6 bits are needed to initialize
# register for tail-biting
stream1 = np.convolve(dat_pad, gen1, mode='valid') % 2
stream2 = np.convolve(dat_pad, gen2, mode='valid') % 2
enc = [val for pair in zip(stream1, stream2) for val in pair]
return [enc[i] for i in range(len(enc)) if punct[i % 3]]
# To create a generator matrix for a code, we encode each row
# of the identity matrix. Note that the CRC is not quite linear
# because of the check mask so we apply the lamda function to
# invert it. Given a 37 bit media reference we can encode by
# ref * spotify_generator + spotify_mask (mod 2)
_i37 = np.identity(37, dtype=bool)
crc_generator = [_i37[r].tolist() +
list(map(lambda x : 1-x, calc_spotify_crc(_i37[r].tolist())))
for r in range(37)]
spotify_generator = 1*np.array([encode_cc(crc_generator[r]) for r in range(37)], dtype=bool)
del _i37
spotify_mask = 1*np.array(encode_cc(37*[0] + 8*[1]), dtype=bool)
# The following matrix is used to "invert" the convolutional code.
# In particular, we choose a 45 vector basis for the columns of the
# generator matrix (by deleting those in positions equal to 2 mod 4)
# and then inverting the matrix. By selecting the corresponding 45
# elements of the convolutionally encoded vector and multiplying
# on the right by this matrix, we get back to the unencoded data,
# assuming there are no errors.
# Note: numpy does not invert binary matrices, i.e. GF(2), so we
# hard code the following 3 row vectors to generate the matrix.
conv_gen = [[0,1,0,1,1,1,1,0,1,1,0,0,0,1]+31*[0],
[1,0,1,0,1,0,1,0,0,0,1,1,1] + 32*[0],
[0,0,1,0,1,1,1,1,1,1,0,0,1] + 32*[0] ]
conv_generator_inv = 1*np.array([shift_right(conv_gen[(s-27) % 3],s) for s in range(27,72)], dtype=bool)
# Given an integer media reference, returns list of 20 barcode levels
def spotify_bar_code(ref):
bin37 = np.array([int_to_bin(ref, 37, 'l')], dtype=bool)
enc = (np.add(1*np.dot(bin37, spotify_generator), spotify_mask) % 2).flatten()
perm = [enc[7*i % 60] for i in range(60)]
return [gray_code[4*perm[i]+2*perm[i+1]+perm[i+2]] for i in range(0,len(perm),3)]
# Equivalent function but using CRC and CC encoders.
def spotify_bar_code2(ref):
bin37 = int_to_bin(ref, 37, 'l')
enc_crc = bin37 + calc_spotify_crc(bin37)
enc_cc = encode_cc(enc_crc)
perm = [enc_cc[7*i % 60] for i in range(60)]
return [gray_code[4*perm[i]+2*perm[i+1]+perm[i+2]] for i in range(0,len(perm),3)]
# Given 20 (clean) barcode levels, returns media reference
def spotify_bar_decode(levels):
level_bits = np.array([gray_code_inv[levels[i]] for i in range(20)], dtype=bool).flatten()
conv_bits = [level_bits[43*i % 60] for i in range(60)]
cols = [i for i in range(60) if i % 4 != 2] # columns to invert
conv_bits45 = np.array([conv_bits[c] for c in cols], dtype=bool)
bin45 = (1*np.dot(conv_bits45, conv_generator_inv) % 2).tolist()
if check_spotify_crc(bin45):
return bin_to_int(bin45, 37)
else:
print('Error in levels; Use real decoder!!!')
return -1
And example:
>>> levels = [5,7,4,1,4,6,6,0,2,4,3,4,6,7,5,5,6,0,5,0]
>>> spotify_bar_decode(levels)
57639171874
>>> spotify_barcode(57639171874)
[5, 7, 4, 1, 4, 6, 6, 0, 2, 4, 3, 4, 6, 7, 5, 5, 6, 0, 5, 0]

Simulink model 'to workspace' output

I am trying to control motor torque and am using a workspace variable in Simulink and want to output similar variable to workspace.
I have size(T_u)=[3, 91] whereas the output I am getting from the simulation has size [91, 90]
I am unable to understand why this is so.
Code that I am using:
load('Motor_Param.mat')
t = 1:0.1:10;
T_o = [0.05*(10-t);0.04*(10-t);0.03*(10-t)];
T_d = zeros(size(T_o));
T_e = (T_d - T_o);
C_PD = pid(100,0,10,100);
T_u = zeros(size(T_e));
for k=1:size(T_e,1)
T_u(k,:) = lsim(C_PD,T_e(k,:),t);
%T_u(1,:)= -45.0450000000000 -44.5444552724092 -44.0439110892737 -43.5433674500493 -43.0428243541925 -42.5422818011600 -42.0417397904094 -41.5411983213986 -41.0406573935862 -40.5401170064312 -40.0395771593933 -39.5390378519326 -39.0384990835098 -38.5379608535861 -38.0374231616233 -37.5368860070837 -37.0363493894301 -36.5358133081260 -36.0352777626353 -35.5347427524223 -35.0342082769522 -34.5336743356904 -34.0331409281029 -33.5326080536564 -33.0320757118181 -32.5315439020554 -32.0310126238368 -31.5304818766308 -31.0299516599067 -30.5294219731343 -30.0288928157839 -29.5283641873264 -29.0278360872332 -28.5273085149760 -28.0267814700274 -27.5262549518604 -27.0257289599483 -26.5252034937652 -26.0246785527857 -25.5241541364848 -25.0236302443380 -24.5231068758215 -24.0225840304120 -23.5220617075865 -23.0215399068228 -22.5210186275990 -22.0204978693939 -21.5199776316868 -21.0194579139572 -20.5189387156857 -20.0184200363529 -19.5179018754402 -19.0173842324294 -18.5168671068029 -18.0163504980435 -17.5158344056347 -17.0153188290603 -16.5148037678048 -16.0142892213531 -15.5137751891906 -15.0132616708034 -14.5127486656779 -14.0122361733011 -13.5117241931606 -13.0112127247442 -12.5107017675407 -12.0101913210389 -11.5096813847285 -11.0091719580996 -10.5086630406426 -10.0081546318487 -9.50764673120954 -9.00713933821711 -8.50663245236405 -8.00612607314350 -7.50562020004906 -7.00511483257487 -6.50460997021554 -6.00410561246623 -5.50360175882257 -5.00309840878072 -4.50259556183731 -4.00209321748951 -3.50159137523496 -3.00109003457184 -2.50058919499879 -2.00008885601498 -1.49958901712007 -0.999089677814209 -0.498590837598075 0.00190750402718064
a = sim('Motor_Control','SimulationMode','normal');
out = a.get('T_l')
end
Link to .mat and .slx files is: https://drive.google.com/open?id=1kGeA4Cmt8mEeM3ku_C4NtXclVlHsssuw
If you set the Save format in the To Workspace block to Timeseries the output will have the dimensions of the signal times the number of timesteps.
In your case I activated the option Display->Signals & Ports->Signal dimensions and the signal dimensions in your model look like this:
So the signal that you output to the workspace has the size 90. Now if I print size(out.Data) I get
ans = 138 90
where 90 is the signal dimension and 138 is the number of timesteps in your Simulink model.
You could now use the last row of the data (which has the length 90) and add it to your array.
I edit your code, the code has [21,3] output size. "21" is coming from (t_final*1/sample_time+1)
In your code, time t should start from 0.
Motor_Control.slx model has 0.1 sample time if you run the model for a 9 second, the output file has 91 samples for each signal and that's why you have [91, 90] sized output. I download from your drive link and this Simulink model has 2 sec. simulation.
T_u is used as an input of the Simulink model, it is not constant so T_u must be time series.
The edited code is below;
load('Motor_Param.mat')
t = 0:0.1:10;
T_o = [0.05*(10-t);0.04*(10-t);0.03*(10-t)];
T_d = zeros(size(T_o));
T_e = (T_d - T_o);
C_PD = pid(100,0,10,100);
T_u = timeseries(zeros(size(T_e)),t);
for k=1:size(T_e,1)
T_u.Data(k,:) = lsim(C_PD,T_e(k,:),t);
a = sim('Motor_Control','SimulationMode','normal');
out = a.get('T_l')
end

Ghostscript -- convert PS to PNG, rotate, and scale

I have an application that creates very nice data plots rendered in PostScript with letter size and landscape mode. An example of the input file is at http://febo.com/uploads/blip.ps. [ Note: this image renders properly in a viewer, but the PNG conversion comes out with the image sideways. ] I need to convert these PostScript files into PNG images that are scaled down and rotated 90 degrees for web presentation.
I want to do this with ghostscript and no other external tool, because the conversion program will be used on both Windows and Linux systems and gs seems to be a common denominator. (I'm creating a perl script with a "PS2png" function that will call gs, but I don't think that's relevant to the question.)
I've searched the web and spent a couple of days trying to modify examples I've found, but nothing I have tried does the combination of (a) rotate, (b) resize, (c) maintain the aspect ratio and (d) avoid clipping.
I did find an example that injects a "scale" command into the postscript stream, and that seems to work well to scale the image to the desired size while maintaining the aspect ratio. But I can't find a way to rotate the resized image so that the, e.g., 601 x 792 point (2504 x 3300 pixel) postscript input becomes an 800 x 608 pixel png output.
I'm looking for the ghostscript/postscript fu that I can pass to the gs command line to accomplish this.
I've tried gs command lines with various combinations of -dFIXEDMEDIA, -dFitPage, -dAutoRotatePages=/None, or /All, -c "<> setpagedevice", changing -dDISPLAYWIDTHPOINTS and -dDISPLAYHEIGHTPOINTS, -g[width]x[height], -dUseCropBox with rotated coordinates, and other things I've forgotten. None of those worked, though it wouldn't surprise me if there's a magic combination of some of them that will. I just haven't been able to find it.
Here is the core code that produces the scaled but not rotated output:
## "$molps" is the input ps file read to a variable
## insert the PS "scale" command
$molps = $sf . " " . $sf . " scale\n" . $molps;
$gsopt1 = " -r300 -dGraphicsAlphaBits=4 -dTextAlphaBits=4";
$gsopt1 = $gsopt1 . " -dDEVICEWIDTHPOINTS=$device_width_points";
$gsopt1 = $gsopt1 . " -dDEVICEHEIGHTPOINTS=$device_height_points";
$gsopt1 = $gsopt1 . " -sOutputFile=" . $outfile;
$gscmd = "gs -q -sDEVICE=pnggray -dNOPAUSE -dBATCH " . $gsopt1 . " - ";
system("echo \"$molps\" \| $gscmd");
$device_width_points and $device_height_points are calculated by taking the original image size and applying the scaling factor $sf.
I'll be grateful to anyone who can show me the way to accomplish this. Thanks!
Better Answer:
You almost had it with your initial research. Just set orientation in the gs call:
... | gs ... -dAutoRotatePages=/None -c '<</Orientation 3>> setpagedevice' ...
cf. discussion of setpagedevice in the Red Book, and ghostscript docs (just before section 6.2)
Original Answer:
As well as "scale", you need "rotate" and "translate", not necessarily in that order.
Presumably these are single-page PostScript files?
If you know the bounding box of the Postscript, and the dimensions of the png, it is not too arduous to calculate the necessary transformation. It'll be about one line of code. You just need to ensure you inject it in the correct place.
Chapter 6 of the Blue Book has lots of details
A ubc.ca paper provides some illustrated examples (skip to page 4)
Simple PostScript file to play around with. You'll just need the three translate,scale,rotate commands in some order. The rest is for demonstrating what's going on.
%!
% function to define a 400x400 box outline, origin at 0,0 (bottom left)
/box { 0 0 moveto 0 400 lineto 400 400 lineto 400 0 lineto closepath } def
box clip % pretend the box is our bounding box
clippath stroke % draw initial black bounding box
(Helvetica) findfont 50 scalefont setfont % setup a font
% draw box, and show some text # 100,100
box stroke
100 100 moveto (original) show
% try out some transforms
1 0 0 setrgbcolor % red
.5 .5 scale
box stroke
100 100 moveto (+scaled) show
0 1 0 setrgbcolor % green
300 100 translate
box stroke
100 100 moveto (+translated) show
0 0 1 setrgbcolor % blue
45 rotate
box stroke
100 100 moveto (+rotated) show
showpage
It may be possible to insert the calculated transformation into the gs commandline like this:
... | gs ... -c '1 2 scale 3 4 translate 5 6 rotate' -# ...
Thanks to JHNC, I think I have it licked now, and for the benefit of posterity, here's what worked. (Please upvote JHNC, not this answer.)
## code to determine original size, scaling factor, rotation goes above
my $device_width_points;
my $device_height_points;
my $orientation;
if ($rotation) {
$orientation = 3;
$device_width_points = $ytotal_png_pt;
$device_height_points = $xtotal_png_pt;
} else {
$orientation = 0;
$device_width_points = $xtotal_png_pt;
$device_height_points = $ytotal_png_pt;
}
my $orientation_string =
" -dAutoRotatePages=/None -c '<</Orientation " .
$orientation . ">> setpagedevice'";
## $ps = .ps file read into variable
## insert the PS "scale" command
$ps = $sf . " " . $sf . " scale\n" . $ps;
$gsopt1 = " -r300 -dGraphicsAlphaBits=4 -dTextAlphaBits=4";
$gsopt1 = $gsopt1 . " -dDEVICEWIDTHPOINTS=$device_width_points";
$gsopt1 = $gsopt1 . " -dDEVICEHEIGHTPOINTS=$device_height_points";
$gsopt1 = $gsopt1 . " -sOutputFile=" . $outfile;
$gsopt1 = $gsopt1 . $orientation_string;
$gscmd = "gs -q -sDEVICE=pnggray -dNOPAUSE -dBATCH " . $gsopt1 . " - ";
system("echo \"$ps\" \| $gscmd");
One of the problems I had was that some options apparently don't play well together -- for example, I tried using the -g option to set the output size in pixels, but in that case the rotation didn't work. Using the DEVICE...POINTS commands instead did work.

How to extract data set from a text file?

Am quite new in the Unix field and I am currently trying to extract data set from a text file. I tried with sed, grep, awk but it seems to only work with extracting lines, but I want to extract an entire dataset... Here is an example of file from which I'd like to extract the 2 data sets (figures after the lines "R.Time Intensity")
[Header]
Application Name LabSolutions
Version 5.87
Data File Name C:\LabSolutions\Data\Antoine\170921_AC_FluoSpectra\069_WT3a derivatized lignin LiCl 430_GPC_FOREVER_430_049.lcd
Output Date 2017-10-12
Output Time 12:07:32
[Configuration]
Instrument Name BOTAN127-Instrument1
Instrument # 1
Line # 1
# of Detectors 3
Detector ID Detector A Detector B PDA
Detector Name Detector A Detector B PDA
# of Channels 1 1 2
[LC Chromatogram(Detector A-Ch1)]
Interval(msec) 500
# of Points 9603
Start Time(min) 0,000
End Time(min) 80,017
Intensity Units mV
Intensity Multiplier 0,001
Ex. Wavelength(nm) 405
Em. Wavelength(nm) 430
R.Time (min) Intensity
0,00000 -709779
0,00833 -709779
0,01667 17
0,02500 3
0,03333 7
0,04167 19
0,05000 9
0,05833 5
0,06667 2
0,07500 24
0,08333 48
[LC Chromatogram(Detector B-Ch1)]
Interval(msec) 500
# of Points 9603
Start Time(min) 0,000
End Time(min) 80,017
Intensity Units mV
Intensity Multiplier 0,001
R.Time (min) Intensity
0,00000 149
0,00833 149
0,01667 -1
I would greatly appreciate any idea. Thanks in advance.
Antoine
awk '/^[^0-9]/&&d{d=0} /R.Time/{d=1}d' file
Brief explanation,
Set d as a flag to determine print line or not
/^[^0-9]/&&d{d=0}: if regex ^[^0-9] matched && d==1, disabled d
/R.Time/{d=1}: if string "R.Time" searched, enabled d
awk '/R.Time/,/LC/' file|grep -v -E "R.Time|LC"
grep part will remove the R.Time and LC lines that come as a part of the output from awk
I think it's a job for sed.
sed '/R.Time/!d;:A;N;/\n$/!bA' infile

How to edit exif metadata by graphicsmagick command?

How to edit or add exif metadata by graphicsmagick command? I've tried the following:
gm convert -set EXIF:XPKeywords "bird, sleep, moon" bird.jpg bird2.jpg
My command is executing successfully and the image is creating but the exif metadata is not updating.
I don't believe you can do that with GraphicsMagick, and I would suggest exiv2 like this:
exiv2 -M"add Exif.Image.XPKeywords Ascii 'bird,sleep,moon'" image.jpg
Then you can view them with jhead too:
jhead -v image.jpg
JFIF SOI marker: Units: 0 (aspect ratio) X-density=1 Y-density=1
Exif header 50 bytes long
Exif section in Intel order
(dir has 1 entries)
Windows-XP keywords = "bird,sleep,moon"
Approximate quality factor for qtable 0: 92 (scale 16.28, var 1.13)
Approximate quality factor for qtable 1: 92 (scale 16.20, var 0.15)
JPEG image is 2000w * 2000h, 3 color components, 8 bits per sample
File name : image.jpg
File size : 6968929 bytes
File date : 2015:10:20 09:23:24
Resolution : 2000 x 2000