What causes "%s: sorry, entropy optimization was not compiled " in DrKLO/Telegram?

Drop the -optimize flag and rely on default coding.

%s: sorry, entropy optimization was not compiled

Error message

%s: sorry, entropy optimization was not compiled

What it means

The -optimize (or -optimise) flag was passed but the build lacks ENTROPY_OPT_SUPPORTED, the compile-time feature enabling Huffman table optimization. jpegtran exits with failure at parse time; no processing occurs.

Source

Thrown at TMessagesProj/jni/mozjpeg/jpegtran.c:290

    } else if (keymatch(arg, "maxmemory", 3)) {
      /* Maximum memory in Kb (or Mb with 'm'). */
      long lval;
      char ch = 'x';

      if (++argn >= argc)       /* advance to next argument */
        usage();
      if (sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
        usage();
      if (ch == 'm' || ch == 'M')
        lval *= 1000L;
      cinfo->mem->max_memory_to_use = lval * 1000L;

    } else if (keymatch(arg, "optimize", 1) || keymatch(arg, "optimise", 1)) {
      /* Enable entropy parm optimization. */
#ifdef ENTROPY_OPT_SUPPORTED
      cinfo->optimize_coding = TRUE;
#else
      fprintf(stderr, "%s: sorry, entropy optimization was not compiled\n",
              progname);
      exit(EXIT_FAILURE);
#endif

    } else if (keymatch(arg, "outfile", 4)) {
      /* Set output file name. */
      if (++argn >= argc)       /* advance to next argument */
        usage();
      outfilename = argv[argn]; /* save it away for later use */

    } else if (keymatch(arg, "perfect", 2)) {
      /* Fail if there is any partial edge MCUs that the transform can't
       * handle. */
      transformoption.perfect = TRUE;

    } else if (keymatch(arg, "progressive", 2)) {
      /* Select simple progressive mode. */
#ifdef C_PROGRESSIVE_SUPPORTED

View on GitHub (pinned to 45ab8f4308)

Solutions

Drop the -optimize flag and rely on default coding.
Rebuild with ENTROPY_OPT_SUPPORTED defined (standard in libjpeg-turbo/mozjpeg; verify the CMake option).
Probe for the feature at build time and disable the flag conditionally.
Use mozjpeg, which enables optimization by default, instead of stripped libjpeg.

Example fix

# before
./jpegtran -optimize in.jpg > out.jpg
# after: drop the flag or rebuild
./jpegtran in.jpg > out.jpg   # or rebuild mozjpeg with ENTROPY_OPT_SUPPORTED

Defensive patterns

Strategy: type-guard

Type guard

#ifndef ENTROPY_OPT_SUPPORTED
#error "entropy optimization unavailable; do not pass -optimize"
#endif

Prevention

Guard -optimize behind a feature probe.
Prefer mozjpeg, which optimizes by default.
Drop the flag on stripped builds.

When it happens

Trigger: Invoking jpegtran -optimize on a libjpeg/mozjpeg build compiled without entropy optimization support. The flag is recognized but its handler is in the #else branch.

Common situations: Ultra-minimal decode-oriented builds, older embedded libjpeg variants, or a misconfigured CMake build that set -DWITH_ENTROPY_OPT=0 (if exposed). Command copied from documentation that assumes the feature is present.

Related errors

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/7d1a21c09f983d3c. Report an issue: GitHub.