# 07_codecs.patch   (rebased for pjsip 2.17)
#
# Two unrelated codec defaults reverted to sipsimple's preferred values:
#
#   1. opus.c - advertise Opus as mono (channel_cnt = 1) instead of
#      pjsip's RFC 7587 §7 default of 2.  Matches the rest of the audio
#      pipeline (audiodev, AEC, telephone-event are all mono) and
#      avoids the SDP "channels=2" annotation that confuses some
#      B2BUAs.
#
#   2. ffmpeg_vid_codecs.c - retune the software-x264 encoder:
#
#        preset:  veryfast              -> ultrafast
#        tune:    animation+zerolatency -> fastdecode+zerolatency
#
#      `ultrafast` trades a small amount of visual quality for
#      noticeably less encoder CPU and lower glass-to-glass latency -
#      the right knob for interactive video conferencing where a
#      one-frame delay is more user-visible than a few percent of
#      compression efficiency.
#
#      `fastdecode+zerolatency` swaps the `animation` content tune
#      (which biases the rate controller toward flat-cell cartoon
#      content) for `fastdecode`, which constrains the bitstream so
#      the peer's decoder can run without buffering whole GOPs
#      (no B-frames, no CABAC).  `zerolatency` is kept - that's the
#      one that disables look-ahead and frame reordering, which is
#      mandatory for real-time use.
#
#      Only the software libx264 path is affected.  On Apple Silicon
#      H264 goes through VideoToolbox (hardware encoder), which
#      ignores these AV_OPT_SET calls entirely, so this is a no-op
#      on macOS.  Linux / fallback paths get the new defaults.
#
# Rebase notes (vs the 2.12 version):
#   * 2.17 opus.c uses space indentation (the pjsip 2.13 whitespace
#     sweep).  The original tab-indented hunk is re-cast with spaces.
#   * x264 preset/tune hunk lands at line 570 in 2.17 (was 440 in
#     2.12) but is otherwise identical.
#
# Still NOT ported from the 2.12 version:
#   * PROFILE_H264_HIGH support (2.12 hunks @266 and @404 in
#     ffmpeg_vid_codecs.c).  pjmedia needs the constant + the
#     `case PROFILE_H264_HIGH: profile = "high";` arm to recognise
#     High Profile in the SDP fmtp `profile-level-id` field and pass
#     it through to the encoder.  Without it, an offer of High
#     Profile from the peer gets answered with Baseline, costing
#     compression headroom on detailed scenes.  Will be folded into
#     the tier-5 ffmpeg_vid_codecs rebase.
#   * AVCODEC_HAS_ENCODE simplification - subsumed by 2.17's
#     FFmpeg 5+ send_frame/receive_packet migration upstream.
#   * avcodec_get_frame_defaults #ifdef rewrite - also subsumed
#     upstream; the old API is gone in FFmpeg 3+.
#
--- pjsip_orig/pjmedia/src/pjmedia-codec/opus.c
+++ pjsip/pjmedia/src/pjmedia-codec/opus.c
@@ -554,7 +554,7 @@
          */
         codecs[0].encoding_name = pj_str("opus");
         codecs[0].clock_rate    = 48000;
-        codecs[0].channel_cnt   = 2;
+        codecs[0].channel_cnt   = 1;
         *count = 1;
     }
 
--- pjsip_orig/pjmedia/src/pjmedia-codec/ffmpeg_vid_codecs.c
+++ pjsip/pjmedia/src/pjmedia-codec/ffmpeg_vid_codecs.c
@@ -265,6 +265,7 @@
 /* H264 constants */
 #define PROFILE_H264_BASELINE           66
 #define PROFILE_H264_MAIN               77
+#define PROFILE_H264_HIGH               100
 
 /* Codec specific functions */
 #if  PJMEDIA_HAS_FFMPEG_CODEC_VP8 || PJMEDIA_HAS_FFMPEG_CODEC_VP9
@@ -531,6 +532,9 @@
         case PROFILE_H264_MAIN:
             profile = "main";
             break;
+        case PROFILE_H264_HIGH:
+            profile = "high";
+            break;
         default:
             break;
         }
@@ -567,10 +567,10 @@
         /* Misc x264 settings (performance, quality, latency, etc).
          * Let's just use the x264 predefined preset & tune.
          */
-        if (!AV_OPT_SET(ctx->priv_data, "preset", "veryfast", 0)) {
-            PJ_LOG(3, (THIS_FILE, "Failed to set x264 preset 'veryfast'"));
+        if (!AV_OPT_SET(ctx->priv_data, "preset", "ultrafast", 0)) {
+            PJ_LOG(3, (THIS_FILE, "Failed to set x264 preset 'ultrafast'"));
         }
-        if (!AV_OPT_SET(ctx->priv_data, "tune", "animation+zerolatency", 0)) {
-            PJ_LOG(3, (THIS_FILE, "Failed to set x264 tune 'zerolatency'"));
+        if (!AV_OPT_SET(ctx->priv_data, "tune", "fastdecode+zerolatency", 0)) {
+            PJ_LOG(3, (THIS_FILE, "Failed to set x264 tune 'fastdecode+zerolatency'"));
         }
     }