Bad Apple!! in C++ template errors

README.md

How to run

0. Install GCC (tested on 12.2.0) and pyvideoreader (pip3 install pyvideoreader)
1. Enter target terminal size to terminal_size.txt
2. Replace line 7 of preprocess.py with:

    video = VideoReader('<path to your video>')

and line 10 of generate_cpp.py with:

        '<path to your video>').number_of_frames)()

(thanks @56independent for a comment!)

3. Run:

python preprocess.py
python generate_cpp.py

4. Run with buffering so that animation plays with original 30fps

g++ sources/badapple_*.cpp |& python buffer.py

5. Or just play (this doesn't keep up speed and passes very fast)

g++ sources/badapple_*.cpp

buffer.py

import os
import sys
import time

terminal_size = (lambda: [int(i) for i in open("terminal_size.txt").read().split()])()
FRAME_TIME = 1/30

while True:
    start_time = time.time()
    out = ""
    for i in range(7):
        out += (sys.stdin.readline() or exit())
    sys.stdout.write(out or exit())
    time.sleep(FRAME_TIME - (time.time() - start_time))

generate_cpp.py

from io import StringIO
import numpy as np
import os
import random
import sys
import time
from videoreader import VideoReader

frame_count = (lambda: VideoReader(
    '/home/sppmacd/Videos/badapple.webm').number_of_frames)()
terminal_size = (lambda: [int(i) for i in open("terminal_size.txt").read().split()])()

FUNCTION_NAMES = [
    "i",
    "up",
    "get",
    "load",
    "parse",
    "format"
]

lead_size = len("   10 |     frame<     >(\"")

os.makedirs("sources", exist_ok=True)

def rand_op():
    chars = "+-*/%"
    return chars[random.randrange(len(chars))]

FRAMES_PER_FILE = 200
FRAME_REPETITIONS = 1

for i in range(int(frame_count / FRAMES_PER_FILE) + 1):
    with open(f"sources/badapple_{i:03}.txt", "w") as ascii_file:
        for j in range(FRAMES_PER_FILE):
            frame = i * FRAMES_PER_FILE + j
            print(f"Generating: Frame {frame}/{frame_count} ({frame*100/frame_count:.1f}%)")

            try:
                with open(f"frames/{frame}", "rb") as frame_file:
                    frame_data = frame_file.read()
            except FileNotFoundError:
                break

            # FANCY        
            data = StringIO()

            offset = 0
            while offset < len(frame_data) - 2:
                if frame_data[offset] < 10:
                    data.write(" ")
                    offset += 1
                else:
                    longest_white_sequence = 0
                    offset2 = offset
                    while offset2 < len(frame_data) - 2 and frame_data[offset2] >= 10:
                        longest_white_sequence += 1
                        offset2 += 1

                    trailing_length = len("() + ")

                    while longest_white_sequence > 0:
                        required_function_name_length = longest_white_sequence - trailing_length
                        if required_function_name_length <= 0:
                            data.write(f" " * longest_white_sequence)
                            break
                        elif required_function_name_length < len(FUNCTION_NAMES):
                            data.write(f"{FUNCTION_NAMES[required_function_name_length - 1]}() {rand_op()} ")
                            break
                        else:
                            length = random.randrange(1, len(FUNCTION_NAMES) + 1)
                            data.write(f"{FUNCTION_NAMES[length - 1]}() {rand_op()} ")
                            longest_white_sequence -= length + trailing_length

                    offset = offset2

            for _ in range(FRAME_REPETITIONS):
                ascii_file.write(f"    frame<{frame:5}>(")
                ascii_file.write(" "*(terminal_size[0] - lead_size))
                ascii_file.write(data.getvalue())
                ascii_file.write("2);\n")

    # PLAIN
    # ascii_file.write(f"    frame<{i:5.0f}>(")
    # ascii_file.write(" "*(terminal_size[0] - lead_size))
    # for pixel in frame_data:
    #     ascii_file.write("#" if pixel > 10 else " ")
    # ascii_file.write(");\n")

for i in range(int(frame_count / FRAMES_PER_FILE) + 1):
    with open(f"sources/badapple_{i:03}.cpp", "w") as source_file:
        template = open("template.cpp").read()
        template = template.replace("|FRAMES|", open(f"sources/badapple_{i:03}.txt").read())
        source_file.write(template)

preprocess.py

import numpy as np
import os
import sys
import time
from videoreader import VideoReader

video = VideoReader('/home/sppmacd/Videos/badapple.webm')
frame_count = video.number_of_frames
terminal_size = (lambda: [int(i) for i in open("terminal_size.txt").read().split()])()

x_step = video.frame_width / (terminal_size[0])
y_step = video.frame_height / (terminal_size[1] - 8)

os.makedirs("frames", exist_ok=True)

for frame in video:
    print(f"Preprocessing: Frame {video.current_frame_pos}/{frame_count} ({video.current_frame_pos*100/frame_count:.1f}%)")

    with open(f"frames/{int(video.current_frame_pos - 1)}", "wb") as image:
        # TODO: Interpolate
        for scanline_idx in np.arange(0, video.frame_height, y_step):
            scanline = frame[int(scanline_idx)]
            for pixel_idx in np.arange(0, video.frame_width, x_step):
                pixel = scanline[int(pixel_idx)]
                image.write(bytes([pixel[0]]))

template.cpp

template<int I>
struct Idx { };

int i();
int up();
int get();
int load();
int parse();
int format();

struct Foo {};

template<class T>
struct InvokeResult { using Type = int; };

template<>
struct InvokeResult<int> {};

template<class T>
using InvokeResultT = typename InvokeResult<T>::Type;

template<int IDX, class T>
auto frame(T) -> InvokeResultT<T> {
}

void bad_apple()
{
|FRAMES|
}

int main()
{
    bad_apple();
}

terminal_size.txt

135 42

is this still working , am having error with installing pyvideopalyer ?

What is your environment (OS, Python version etc)?
Also what error message do you get?

is this still working , am having error with installing pyvideopalyer ?

i think the author meant pyvideoreader, not pyvideoplayer

is this still working , am having error with installing pyvideopalyer ?

i think the author meant pyvideoreader, not pyvideoplayer

yeah my bad, fixed that

This is neat!

It seems like this code is inately tied to a specific video on the disk that does not exist. It links to a home folder of a user which does not exist on most systems, never mind the Videos/badapple.webm file.

To fix this, replace line nine of preprocess.py with:

video = VideoReader('./badapple.webm')

and line 10 of generate_cpp.py with:

'./badapple.webm').number_of_frames)()

And now this program should be portable. You just need to put any webm file called badapple.webm within the directory you are executing the scripts from. It should be black and white for the best results.

It seems like this code is inately tied to a specific video on the disk that does not exist. It links to a home folder of a user which does not exist on most systems, never mind the Videos/badapple.webm file.

To fix this, replace line nine of preprocess.py with:

video = VideoReader('./badapple.webm')

and line 10 of generate_cpp.py with:

'./badapple.webm').number_of_frames)()

And now this program should be portable. You just need to put any webm file called badapple.webm within the directory you are executing the scripts from. It should be black and white for the best results.

Added this to README, thanks for noting that!

Added this to README, thanks for noting that!

You're welcome!

this fire

This does not appear to work on macs, which sneakily use clang instead of gcc (you can check this with g++ --version)

For example when I run it on my machine the substitution error does not print all of line 28, so no animation for me.

% g++ --std=c++11 sources/badapple_000.cpp  
sources/badapple_000.cpp:28:5: error: no matching function for call to 'frame'
sources/badapple_000.cpp:23:6: note: candidate template ignored: substitution failure [with IDX = 0, T = int]: no type named 'Type' in 'InvokeResult<int>'
auto frame(T) -> InvokeResultT<T> {
     ^

I reproduced this on GodBolt. I found that clang will only print the source if the length of the line that is unable to find a proper substitution is 4096 or less.
https://godbolt.org/z/1dKzPh5Wh

However if you switch to GCC, it'll print significantly longer lines.

Not feeling up for installing GCC for this, and a 64 x 64 resolution rendering isn't the dream. Cool idea though!

I think the lines in the preprocess.py are 7 and 8, not 9 and 10.

@sppmacd what IDE or Terminal are you using to print the outputs
as Ive tried this with vsc and it doesn't seem to work

@sppmacd what IDE or Terminal are you using to print the outputs as Ive tried this with vsc and it doesn't seem to work

Konsole, also what's the problem?

@sppmacd what IDE or Terminal are you using to print the outputs as Ive tried this with vsc and it doesn't seem to work

Konsole, also what's the problem?

most of the terminals I'm using is printing new lines pushing the rest of the code up not properly showing the animation
I tried to use ncurses in the header file of your first template file but I seem to have missed something thus asking you for the console that you are using

Have you entered size of your terminal in terminal_size.txt?

You can get it in python using os.get_terminal_size()

I did everything but it was the rolling text that was the issue on standard terminal
but konsole somehow has a fix for that

hmm, strange

The buffer wont work unless I remove the terminal_size. And I have to re-adjust the terminal_size.txt to my current terminal width x length.

Anyway it works like a charm!!

The buffer wont work unless I remove the terminal_size. And I have to re-adjust the terminal_size.txt to my current terminal width x length.
Anyway it works like a charm!!

Yeah the terminal_size.txt had the default width and height of konsole app for Linux
if you are going to use any other app you have to change the size in there with your sizes