opj_compress help: revert 3257261 and indicate 1 again as being the v…

…alue to get lossless for -r. In opj_j2k_setup_encoder(), make sure that ll rates[] <= 1.0 are set to 0. Document 0 as being lossless for -q / tcp_distoratio (#1009)

src/bin/jp2/opj_compress.c

@@ -169,16 +169,17 @@ static void encode_help_display(void)
  fprintf(stdout, " Different compression ratios for successive layers.\n");
  fprintf(stdout,
  " The rate specified for each quality level is the desired\n");
- fprintf(stdout, " compression factor (use 0 for lossless)\n");
+ fprintf(stdout, " compression factor (use 1 for lossless)\n");
  fprintf(stdout, " Decreasing ratios required.\n");
- fprintf(stdout, " Example: -r 20,10,0 means \n");
+ fprintf(stdout, " Example: -r 20,10,1 means \n");
  fprintf(stdout, " quality layer 1: compress 20x, \n");
  fprintf(stdout, " quality layer 2: compress 10x \n");
  fprintf(stdout, " quality layer 3: compress lossless\n");
  fprintf(stdout, " Options -r and -q cannot be used together.\n");
  fprintf(stdout, "-q <psnr value>,<psnr value>,<psnr value>,...\n");
  fprintf(stdout, " Different psnr for successive layers (-q 30,40,50).\n");
- fprintf(stdout, " Increasing PSNR values required.\n");
+ fprintf(stdout, " Increasing PSNR values required, except 0 which can\n");
+ fprintf(stdout, " be used for the last layer to indicate it is lossless.\n");
  fprintf(stdout, " Options -r and -q cannot be used together.\n");
  fprintf(stdout, "-n <number of resolutions>\n");
  fprintf(stdout, " Number of resolutions.\n");

src/lib/openjp2/j2k.c

@@ -7060,6 +7060,10 @@ OPJ_BOOL opj_j2k_setup_encoder(opj_j2k_t *p_j2k,
  tcp->rates[j] = parameters->tcp_rates[j];
  }
  }
+ if (!cp->m_specific_param.m_enc.m_fixed_quality &&
+ tcp->rates[j] <= 1.0) {
+ tcp->rates[j] = 0.0; /* force lossless */
+ }
  }
 
  tcp->csty = (OPJ_UINT32)parameters->csty;

src/lib/openjp2/openjpeg.h

@@ -381,9 +381,12 @@ typedef struct opj_cparameters {
  OPJ_UINT32 numpocs;
  /** number of layers */
  int tcp_numlayers;
- /** rates of layers - might be subsequently limited by the max_cs_size field */
+ /** rates of layers - might be subsequently limited by the max_cs_size field.
+ * Should be decreasing. 1 can be
+ * used as last value to indicate the last layer is lossless. */
  float tcp_rates[100];
- /** different psnr for successive layers */
+ /** different psnr for successive layers. Should be increasing. 0 can be
+ * used as last value to indicate the last layer is lossless. */
  float tcp_distoratio[100];
  /** number of resolutions */
  int numresolution;