shithub: opus-tools

Info  •  Files  •  Log  •  Branches

opusenc: Implement --channels discrete switch

Resolves https://github.com/xiph/opus-tools/pull/80
Signed-off-by: Mark Harris <mark.hsj@gmail.com>

--- a/man/opusenc.1

+++ b/man/opusenc.1

@@ -312,12 +312,13 @@

 The length will always be ignored when it is implausible (very small or very

 large), but some stdin usage may still need this option to avoid truncation.

 .TP

-.B --channels <ambix>

+.B --channels <ambix, discrete>

 Override the format of the input channels.

 The "ambix" option indicates that the input is ambisonics using ACN channel

 ordering with SN3D normalization. All channels in a full ambisonics order must

 be included. A pair of non-diegetic stereo channels can be optionally placed

-after the ambisonics channels.

+after the ambisonics channels. The option "discrete" forces uncoupled

+channels.

 .SS "Diagnostic options"

 .TP

 .BI --serial " N"

--- a/src/encoder.h

+++ b/src/encoder.h

@@ -18,6 +18,7 @@

 #define CHANNELS_FORMAT_DEFAULT  0

 #define CHANNELS_FORMAT_AMBIX    1

+#define CHANNELS_FORMAT_DISCRETE 2

 typedef long (*audio_read_func)(void *src, float *buffer, int samples);

--- a/src/opusenc.c

+++ b/src/opusenc.c

@@ -176,7 +176,7 @@

   printf(" --raw-chan n       Set number of channels for raw input (default: 2)\n");

   printf(" --raw-endianness n 1 for big endian, 0 for little (default: 0)\n");

   printf(" --ignorelength     Ignore the data length in Wave headers\n");

-  printf(" --channels <ambix> Override the format of the input channels\n");

+  printf(" --channels         Override the format of the input channels (ambix, discrete)\n");

   printf("\nDiagnostic options:\n");

   printf(" --serial n         Force use of a specific stream serial number\n");

   printf(" --save-range file  Save check values for every frame to a file\n");

@@ -637,9 +637,11 @@

         } else if (strcmp(optname, "channels")==0) {

           if (strcmp(optarg, "ambix")==0) {

             inopt.channels_format=CHANNELS_FORMAT_AMBIX;

+          } else if (strcmp(optarg, "discrete")==0) {

+            inopt.channels_format=CHANNELS_FORMAT_DISCRETE;

           } else {

             fatal("Invalid input format: %s\n"

-              "--channels only supports 'ambix'\n",

+              "--channels only supports 'ambix' or 'discrete'\n",

               optarg);

           }

         } else if (strcmp(optname, "serial")==0) {

@@ -881,6 +883,11 @@

     fatal("Error: downmixing is currently unimplemented for ambisonics input.\n");

   }

+  if (downmix>0&&inopt.channels_format==CHANNELS_FORMAT_DISCRETE) {

+    /*Downmix of uncoupled channels not specified.*/

+    fatal("Error: downmixing is currently unimplemented for independent input.\n");

+  }

+

   if (inopt.channels_format==CHANNELS_FORMAT_DEFAULT) {

     if (downmix==0&&inopt.channels>2&&bitrate>0&&bitrate<(16000*inopt.channels)) {

       if (!quiet) fprintf(stderr,"Notice: Surround bitrate less than 16 kbit/s per channel, downmixing.\n");

@@ -904,6 +911,8 @@

       (including the non-diegetic stereo track). For other orders with no

       demixing matrices currently available, use channel mapping 2.*/

     mapping_family=(chan>=4&&chan<=18)?3:2;

+  } else if (inopt.channels_format==CHANNELS_FORMAT_DISCRETE) {

+    mapping_family=255;

   } else {

     mapping_family=chan>8?255:chan>2;

   }