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| 1 | +#!/usr/bin/env python3 |
| 2 | +# -*- coding: utf-8 -*- |
| 3 | +# |
| 4 | +# reencode_to_target_size.py |
| 5 | +# |
| 6 | +# Re-encode audio/video to MP3, ensuring file size is under some target MB. |
| 7 | +# - Binary search on bitrate from 8 kbps → 320 kbps |
| 8 | +# - Up to max_iterations |
| 9 | +# - If we can’t improve or we’re within a tolerance, we stop early. |
| 10 | +# |
| 11 | +# (c) 2024. Use at your own risk. |
| 12 | + |
| 13 | +import sys |
| 14 | +import os |
| 15 | +import subprocess |
| 16 | +import shutil |
| 17 | + |
| 18 | +# =========== GLOBALS ============ |
| 19 | +TELEGRAM_BOT_SIZE_LIMIT_MB = 20.0 |
| 20 | +SAFETY_MARGIN_MB = 0.1 |
| 21 | +DEFAULT_TARGET_MB = TELEGRAM_BOT_SIZE_LIMIT_MB - SAFETY_MARGIN_MB |
| 22 | + |
| 23 | +DEFAULT_MAX_ITERATIONS = 12 # Increase default to e.g. 12 |
| 24 | +STALE_TRIES_LIMIT = 2 # If we fail to improve for 2 consecutive tries, bail out |
| 25 | + |
| 26 | +# TOLERANCE: If we’re within X bytes of the target, we’ll consider that “close enough” |
| 27 | +SIZE_TOLERANCE_BYTES = 200_000 # ~200 KB; set to 0 to disable |
| 28 | +# ================================= |
| 29 | + |
| 30 | +def hz_line(char='-'): |
| 31 | + import shutil |
| 32 | + try: |
| 33 | + cols, _ = shutil.get_terminal_size(fallback=(80, 24)) |
| 34 | + except: |
| 35 | + cols = 80 |
| 36 | + print(char * cols) |
| 37 | + |
| 38 | +def get_duration_seconds(inputfile): |
| 39 | + cmd = [ |
| 40 | + "ffprobe", "-v", "error", |
| 41 | + "-select_streams", "a:0", |
| 42 | + "-show_entries", "format=duration", |
| 43 | + "-of", "default=noprint_wrappers=1:nokey=1", |
| 44 | + inputfile |
| 45 | + ] |
| 46 | + try: |
| 47 | + proc = subprocess.run(cmd, capture_output=True, text=True, check=True) |
| 48 | + duration_str = proc.stdout.strip() |
| 49 | + return float(duration_str) if duration_str else None |
| 50 | + except Exception as e: |
| 51 | + print(f"[ERROR] ffprobe failed: {e}") |
| 52 | + return None |
| 53 | + |
| 54 | +def reencode_mp3_strict(inputfile, target_mb, max_iterations): |
| 55 | + duration = get_duration_seconds(inputfile) |
| 56 | + if not duration: |
| 57 | + print("[ERROR] Could not get duration. Aborting.") |
| 58 | + return None |
| 59 | + |
| 60 | + target_bytes = int(target_mb * 1024 * 1024) |
| 61 | + min_bitrate = 8 |
| 62 | + max_bitrate = 320 |
| 63 | + |
| 64 | + base, ext = os.path.splitext(inputfile) |
| 65 | + ext_lower = ext.lower() |
| 66 | + if ext_lower not in (".mp3", ".aac", ".wav", ".m4a", ".mp4", ".ogg", ".flac"): |
| 67 | + ext_lower = ".mp3" |
| 68 | + |
| 69 | + outputfile = f"{base}_{target_mb}MB_recode.mp3" |
| 70 | + |
| 71 | + hz_line() |
| 72 | + print(f"[INFO] Input: {inputfile}") |
| 73 | + print(f"[INFO] Duration: {duration:.1f} s") |
| 74 | + print(f"[INFO] Target: {target_mb} MB → {target_bytes} bytes") |
| 75 | + print(f"[INFO] Output file: {outputfile}") |
| 76 | + print(f"[INFO] Max iterations: {max_iterations}") |
| 77 | + hz_line() |
| 78 | + |
| 79 | + best_size = 0 |
| 80 | + best_bitrate = None |
| 81 | + stale_tries = 0 # how many times in a row we fail to improve |
| 82 | + prev_size = None # to see if two consecutive attempts produce same size |
| 83 | + |
| 84 | + iteration = 1 |
| 85 | + while iteration <= max_iterations and min_bitrate <= max_bitrate: |
| 86 | + current_bitrate = (min_bitrate + max_bitrate) // 2 |
| 87 | + print(f"[Iteration {iteration}] Trying bitrate: {current_bitrate} kbps") |
| 88 | + |
| 89 | + tmp_out = outputfile + ".temp" |
| 90 | + cmd = [ |
| 91 | + "ffmpeg", "-v", "error", "-y", |
| 92 | + "-i", inputfile, |
| 93 | + "-vn", |
| 94 | + "-c:a", "libmp3lame", |
| 95 | + f"-b:a", f"{current_bitrate}k", |
| 96 | + "-f", "mp3", |
| 97 | + tmp_out |
| 98 | + ] |
| 99 | + try: |
| 100 | + subprocess.run(cmd, check=True) |
| 101 | + except subprocess.CalledProcessError as e: |
| 102 | + print(f"[ERROR] ffmpeg encoding failed: {e}") |
| 103 | + return None |
| 104 | + |
| 105 | + actual_size = os.path.getsize(tmp_out) |
| 106 | + print(f" -> size: {actual_size} bytes") |
| 107 | + |
| 108 | + # If under the limit |
| 109 | + if actual_size <= target_bytes: |
| 110 | + # Check if it’s bigger than our previous best |
| 111 | + if actual_size > best_size: |
| 112 | + best_size = actual_size |
| 113 | + best_bitrate = current_bitrate |
| 114 | + shutil.copyfile(tmp_out, outputfile + ".best") |
| 115 | + print(f" -> New best: {best_size} bytes at {best_bitrate} kbps") |
| 116 | + stale_tries = 0 # reset |
| 117 | + else: |
| 118 | + # Didn’t improve |
| 119 | + stale_tries += 1 |
| 120 | + print(f" -> Not an improvement. stale_tries={stale_tries}") |
| 121 | + # Then try increasing min_bitrate to see if we can get closer |
| 122 | + min_bitrate = current_bitrate + 1 |
| 123 | + else: |
| 124 | + # Over the limit => lower bitrate |
| 125 | + stale_tries += 1 |
| 126 | + print(f" -> Over target. stale_tries={stale_tries}") |
| 127 | + max_bitrate = current_bitrate - 1 |
| 128 | + |
| 129 | + # If consecutive attempts produce same size, we might be pinned by encoder |
| 130 | + if prev_size is not None and prev_size == actual_size: |
| 131 | + stale_tries += 1 |
| 132 | + print(" -> Same file size as previous iteration. Possibly pinned by encoder constraints.") |
| 133 | + |
| 134 | + prev_size = actual_size |
| 135 | + os.remove(tmp_out) |
| 136 | + |
| 137 | + # Check if we’re within tolerance |
| 138 | + if best_size > 0 and SIZE_TOLERANCE_BYTES > 0: |
| 139 | + diff = target_bytes - best_size |
| 140 | + if 0 <= diff <= SIZE_TOLERANCE_BYTES: |
| 141 | + print(f"[INFO] Within {SIZE_TOLERANCE_BYTES} bytes of target; stopping early.") |
| 142 | + break |
| 143 | + |
| 144 | + # If we’ve not improved for too many tries, break |
| 145 | + if stale_tries >= STALE_TRIES_LIMIT: |
| 146 | + print(f"[INFO] Reached stale tries limit ({STALE_TRIES_LIMIT}). Stopping.") |
| 147 | + break |
| 148 | + |
| 149 | + iteration += 1 |
| 150 | + print() |
| 151 | + |
| 152 | + best_file = outputfile + ".best" |
| 153 | + if os.path.exists(best_file): |
| 154 | + # Move final |
| 155 | + shutil.move(best_file, outputfile) |
| 156 | + final_size = os.path.getsize(outputfile) |
| 157 | + print(f"[FINAL] Best bitrate: {best_bitrate} kbps, size: {final_size} bytes") |
| 158 | + if final_size > target_bytes: |
| 159 | + print("[WARN] Final is STILL OVER target, but we can't do better with given constraints.") |
| 160 | + else: |
| 161 | + print("[INFO] Final is under target!") |
| 162 | + return outputfile |
| 163 | + else: |
| 164 | + print("[ERROR] Could not get under target (or no .best file).") |
| 165 | + return None |
| 166 | + |
| 167 | +def main(): |
| 168 | + if len(sys.argv) < 2: |
| 169 | + print(f"Usage: {sys.argv[0]} <inputfile> [<targetMB>] [<max_iterations>]") |
| 170 | + sys.exit(1) |
| 171 | + |
| 172 | + inputfile = sys.argv[1] |
| 173 | + if not os.path.isfile(inputfile): |
| 174 | + print(f"[ERROR] File not found: {inputfile}") |
| 175 | + sys.exit(2) |
| 176 | + |
| 177 | + if len(sys.argv) >= 3: |
| 178 | + target_mb = float(sys.argv[2]) |
| 179 | + else: |
| 180 | + target_mb = DEFAULT_TARGET_MB |
| 181 | + |
| 182 | + if len(sys.argv) >= 4: |
| 183 | + max_iterations = int(sys.argv[3]) |
| 184 | + else: |
| 185 | + max_iterations = DEFAULT_MAX_ITERATIONS |
| 186 | + |
| 187 | + result = reencode_mp3_strict(inputfile, target_mb, max_iterations) |
| 188 | + if result: |
| 189 | + print(f"[DONE] Re-encoded: {result}") |
| 190 | + else: |
| 191 | + print("[FAIL] No acceptable file produced.") |
| 192 | + |
| 193 | +if __name__ == "__main__": |
| 194 | + main() |
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