Fix hyperhdrAdjust: use "brightness", not "scaleOutput"

Tested against a real HyperHDR instance rather than trusting the
schema further. scaleOutput (from the current schema-adjustment.json)
produced no visible change and no trace in serverinfo's echoed-back
adjustment state. brightness (0-100, absent from that same schema)
round-tripped correctly through serverinfo and visibly dimmed real
LEDs -- confirmed live, with piccap as the sole colour source and
only this sink's JSON-RPC calls changing anything.

A schema documents what a command accepts; it does not guarantee
what a given build actually does with each field, and this is a
mismatch between HyperHDR's current dev-branch schema and whatever
build the target instance is actually running. Switched the sink to
brightness (int 0-100) throughout: wire format, config defaults
(minBrightness/maxBrightness, 20-100), status fields, and the reset
sent on close. Renamed the frontend fields and mock to match.
Cross-compiles clean. Bumped to 1.0.4.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/configuration.md

@@ -95,18 +95,23 @@ payload so nothing fragments on a normal Ethernet MTU.
 
 ### `hyperhdrAdjust` — brightness only, via HyperHDR's JSON-RPC
 
-Sends no image at all. Instead it calls HyperHDR's `adjustment` command —
-a post-processing stage that scales output brightness regardless of which
-priority is currently active — so an existing grabber or effect keeps
-deciding colour and only overall brightness reacts to sound.
+Sends no image at all. Instead it calls HyperHDR's `adjustment` command with
+a `brightness` value (0-100) — a post-processing stage that applies
+regardless of which priority is currently active — so an existing grabber or
+capture app keeps deciding colour and only overall brightness reacts to
+sound. Confirmed against a real HyperHDR instance by watching `brightness`
+round-trip through `serverinfo` and the LEDs visibly respond; HyperHDR's own
+`schema-adjustment.json` also documents a `scaleOutput` float (0.0-2.0), but
+that field produced no effect on the same instance — what a schema declares
+and what a given build actually acts on are not always the same thing.
 
 | Key | Default | Meaning |
 | --- | --- | --- |
 | `host` | `""` | HyperHDR's address |
 | `port` | `19444` | HyperHDR's classic JSON-RPC port (not 8090, not 19400) |
 | `level` | `"rms"` | `rms` (steadier) or `peak` (punchier) |
-| `minScale` | `0.3` | brightness during silence; `1.0` is HyperHDR's normal level |
-| `maxScale` | `1.3` | brightness at full level; HyperHDR accepts up to `2.0` |
+| `minBrightness` | `20` | brightness (0-100) during silence |
+| `maxBrightness` | `100` | brightness (0-100) at full level; HyperHDR does not go above 100 |
 
 ### `udp`, `tcp`, `http`
 
@@ -193,8 +198,8 @@ broken output does not take the others down.
 Each sink adds its own fields. `packetsSent`/`bytesSent`/`sendErrors` for the
 datagram sinks, `clients`/`droppedBytes` for the stream servers,
 `connected`/`registered`/`framesSent`/`connectFailures`/`lastError` for the
-visualiser, `connected`/`updatesSent`/`minScale`/`maxScale`/`lastError` for
-the brightness sink.
+visualiser, `connected`/`updatesSent`/`minBrightness`/`maxBrightness`/`lastError`
+for the brightness sink.
 
 ### Diagnostics
 

docs/hyperhdr.md

@@ -169,15 +169,16 @@ lights go fully dark between beats, which looks dramatic and slightly broken.
 ## 4. Keep your grabber's colour, only pulse the brightness
 
 For an ambilight-style setup that already has a real colour source — a
-screen grabber, a USB capture card, an HDMI splitter — routes 1–3 all have
-the same problem: they compete for HyperHDR's priority and *replace* that
-colour with something audio-derived. This route doesn't touch colour at all.
+screen grabber, a USB capture card, a webOS capture app like piccap — routes
+1–3 all have the same problem: they compete for HyperHDR's priority and
+*replace* that colour with something audio-derived. This route doesn't touch
+colour at all.
 
-HyperHDR has a JSON-RPC `adjustment` command that scales output brightness as
-a post-processing step, applied on top of whatever priority is currently
-active. This sink sends nothing but that: no image, no priority
-registration, so the grabber keeps deciding hue and this only turns the
-result up and down with the sound.
+HyperHDR has a JSON-RPC `adjustment` command that sets output brightness
+(0-100) as a post-processing step, applied on top of whatever priority is
+currently active. This sink sends nothing but that: no image, no priority
+registration, so the grabber (or piccap, or whatever else) keeps deciding
+hue and this only turns the result up and down with the sound.
 
 ```
 TV ──RTP or local──► audiocap-service ──JSON-RPC "adjustment"──► HyperHDR
@@ -192,12 +193,21 @@ TV ──RTP or local──► audiocap-service ──JSON-RPC "adjustment"─
 | HyperHDR address | the HyperHDR machine's IP |
 | JSON-RPC port | 19444 (HyperHDR's classic control port — not 8090, the web UI; not 19400, Flatbuffers) |
 | Follows | Average level (steadier) or Peak level (punchier) |
-| Minimum brightness | `1.0` = HyperHDR's normal brightness; lower dims during quiet parts |
-| Maximum brightness | up to `2.0`; boosts past normal on loud peaks |
+| Minimum brightness | `0`-`100`; applied during quiet parts |
+| Maximum brightness | `0`-`100`; applied at full level. HyperHDR does not go above 100 |
 
 Needs a working capture source the same as every other route — see the top
-of this document for picking one. On close, the sink resets `scaleOutput` to
-`1.0` rather than leaving the LEDs stuck at whatever it last sent.
+of this document for picking one. On close, the sink resets brightness to
+`100` rather than leaving the LEDs stuck at whatever it last sent.
+
+The field is `brightness`, confirmed by watching it round-trip through
+`serverinfo` and the LEDs visibly respond on a real HyperHDR/Docker
+instance. HyperHDR's current `schema-adjustment.json` documents a
+`scaleOutput` float (0.0-2.0) instead, which looked like the obvious choice
+and is what this sink sent originally — it had no visible or server-reported
+effect on that same instance. If a future HyperHDR version drops
+`brightness`, this needs re-verifying the same way, not just re-reading the
+schema.
 
 ---
 

frontend/appinfo.json

@@ -1,6 +1,6 @@
 {
   "id": "org.webosbrew.audiocap",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "vendor": "Homebrew",
   "type": "web",
   "main": "index.html",

frontend/js/app.js

@@ -401,12 +401,12 @@
         ],
       },
       {
-        path: 'hyperhdrAdjust.minScale', label: 'Minimum brightness', type: 'number',
-        hint: '1.0 is HyperHDR\'s normal brightness. Below that dims during quiet parts.',
+        path: 'hyperhdrAdjust.minBrightness', label: 'Minimum brightness', type: 'number',
+        hint: '0-100. Applied during quiet parts. 100 is HyperHDR\'s normal brightness.',
       },
       {
-        path: 'hyperhdrAdjust.maxScale', label: 'Maximum brightness', type: 'number',
-        hint: 'Above 1.0 boosts past normal on loud peaks. HyperHDR accepts up to 2.0.',
+        path: 'hyperhdrAdjust.maxBrightness', label: 'Maximum brightness', type: 'number',
+        hint: '0-100. Applied at full level. HyperHDR does not go above 100.',
       },
     ],
 

frontend/js/mock.js

@@ -16,7 +16,7 @@
       mode: 'spectrum', saturation: 1.0, minBrightness: 0.02,
     },
     hyperhdrAdjust: {
-      host: '', port: 19444, minScale: 0.3, maxScale: 1.3, level: 'rms',
+      host: '', port: 19444, minBrightness: 20, maxBrightness: 100, level: 'rms',
     },
     udp: { host: '', port: 4010, multicastTtl: 4 },
     tcp: { port: 4011, maxClients: 4 },

native/src/config.c

@@ -51,8 +51,8 @@ static const char* DEFAULTS_JSON =
     "  \"hyperhdrAdjust\": {"
     "    \"host\": \"\","
     "    \"port\": 19444,"
-    "    \"minScale\": 0.3,"
-    "    \"maxScale\": 1.3,"
+    "    \"minBrightness\": 20,"
+    "    \"maxBrightness\": 100,"
     "    \"level\": \"rms\""
     "  },"
     "  \"udp\": { \"host\": \"\", \"port\": 4010, \"multicastTtl\": 4 },"

native/src/sinks/sink_hyperhdr_adjust.c

@@ -1,12 +1,22 @@
 // Global brightness modulation via HyperHDR's own JSON-RPC "adjustment"
-// command, so a real picture source (HyperHDR's screen grabber, USB capture
-// card, whatever is already driving the LEDs) keeps deciding colour, and
-// only the overall brightness reacts to sound. Unlike every other sink here,
-// this one deliberately sends no picture at all: send one would mean
-// competing for priority against the grabber, replacing its colour outright
-// instead of layering on top of it. "adjustment" is a post-processing stage
-// that applies regardless of which priority is currently active, which is
-// exactly the layering this needs.
+// command, so a real picture source (HyperHDR's screen grabber, a webOS
+// capture app like piccap, whatever is already driving the LEDs) keeps
+// deciding colour, and only the overall brightness reacts to sound. Unlike
+// every other sink here, this one deliberately sends no picture at all:
+// sending one would mean competing for priority against that source,
+// replacing its colour outright instead of layering on top of it.
+// "adjustment" is a post-processing stage that applies regardless of which
+// priority is currently active, which is exactly the layering this needs.
+//
+// The field is "brightness", an integer 0-100 -- confirmed against a real
+// HyperHDR instance (serverinfo echoes it back, and the LEDs visibly
+// responded). The "scaleOutput" float (0-2.0) in HyperHDR's current
+// schema-adjustment.json looked like the obvious candidate and is what an
+// earlier version of this file sent, but it produced no visible or
+// server-reported effect on that same instance -- API docs describe the
+// schema; they do not guarantee what a given build actually does with it.
+// If a future HyperHDR drops "brightness" in favour of "scaleOutput", this
+// will need re-verifying the same way, not just re-reading the schema.
 //
 // Plain newline-delimited JSON over TCP -- HyperHDR's classic control port,
 // default 19444 -- a world simpler than the Flatbuffers image protocol the
@@ -19,6 +29,7 @@
 #include <arpa/inet.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <math.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <poll.h>
@@ -38,8 +49,8 @@ typedef struct {
     char host[128];
     int port;
 
-    float min_scale;
-    float max_scale;
+    int min_brightness; // 0-100
+    int max_brightness; // 0-100
     bool use_rms; // rms is steadier than peak, which reacts to single transients
 
     int fd; // -1 when not connected or still connecting
@@ -154,11 +165,12 @@ static void adjust_write(sink_t* s, const int16_t* pcm, int frames, const dsp_le
         level = 0;
     if (level > 1)
         level = 1;
-    float scale = p->min_scale + level * (p->max_scale - p->min_scale);
+    int brightness = p->min_brightness
+        + (int)lroundf(level * (float)(p->max_brightness - p->min_brightness));
 
     char msg[128];
     int n = snprintf(msg, sizeof(msg),
-        "{\"command\":\"adjustment\",\"adjustment\":{\"scaleOutput\":%.3f}}\n", (double)scale);
+        "{\"command\":\"adjustment\",\"adjustment\":{\"brightness\":%d}}\n", brightness);
     if (n <= 0 || (size_t)n >= sizeof(msg))
         return;
 
@@ -183,8 +195,8 @@ static void adjust_status(sink_t* s, json_writer_t* w)
     jw_str(w, "target", p->host);
     jw_int(w, "port", p->port);
     jw_bool(w, "connected", p->connected);
-    jw_num(w, "minScale", p->min_scale);
-    jw_num(w, "maxScale", p->max_scale);
+    jw_int(w, "minBrightness", p->min_brightness);
+    jw_int(w, "maxBrightness", p->max_brightness);
     jw_int(w, "updatesSent", (long long)p->updates_sent);
     jw_int(w, "connectFailures", (long long)p->connect_failures);
     if (p->last_error[0])
@@ -200,7 +212,7 @@ static void adjust_close(sink_t* s)
         // Best effort: hand brightness back to normal rather than leaving
         // the LEDs stuck at whatever scale was last sent.
         if (p->connected) {
-            static const char reset[] = "{\"command\":\"adjustment\",\"adjustment\":{\"scaleOutput\":1.0}}\n";
+            static const char reset[] = "{\"command\":\"adjustment\",\"adjustment\":{\"brightness\":100}}\n";
             send(p->fd, reset, sizeof(reset) - 1, MSG_NOSIGNAL);
         }
         adjust_disconnect(p);
@@ -214,8 +226,8 @@ static sink_t* adjust_open(const json_value_t* cfg, const audio_format_t* fmt, c
     const json_value_t* sc = json_get(cfg, "hyperhdrAdjust");
     const char* host = json_str(sc, "host", NULL);
     int port = json_int(sc, "port", 19444);
-    float min_scale = (float)json_num(sc, "minScale", 0.3);
-    float max_scale = (float)json_num(sc, "maxScale", 1.3);
+    int min_brightness = json_int(sc, "minBrightness", 20);
+    int max_brightness = json_int(sc, "maxBrightness", 100);
     const char* level_source = json_str(sc, "level", "rms");
 
     if (!host || !*host) {
@@ -226,8 +238,8 @@ static sink_t* adjust_open(const json_value_t* cfg, const audio_format_t* fmt, c
         snprintf(err, errlen, "invalid HyperHDR JSON port %d", port);
         return NULL;
     }
-    if (max_scale <= min_scale) {
-        snprintf(err, errlen, "maxScale must be greater than minScale");
+    if (min_brightness < 0 || max_brightness > 100 || max_brightness <= min_brightness) {
+        snprintf(err, errlen, "brightness range must be 0-100 with max greater than min");
         return NULL;
     }
 
@@ -261,8 +273,8 @@ static sink_t* adjust_open(const json_value_t* cfg, const audio_format_t* fmt, c
 
     snprintf(p->host, sizeof(p->host), "%s", host);
     p->port = port;
-    p->min_scale = min_scale;
-    p->max_scale = max_scale;
+    p->min_brightness = min_brightness;
+    p->max_brightness = max_brightness;
     p->use_rms = strcmp(level_source, "peak") != 0;
 
     s->driver = &sink_driver_hyperhdr_adjust;
@@ -272,8 +284,8 @@ static sink_t* adjust_open(const json_value_t* cfg, const audio_format_t* fmt, c
     s->status = adjust_status;
     s->close = adjust_close;
 
-    INFO("HyperHDR adjustment sink: %s:%d, scaleOutput %.2f..%.2f from %s", host, port,
-        min_scale, max_scale, p->use_rms ? "rms" : "peak");
+    INFO("HyperHDR adjustment sink: %s:%d, brightness %d..%d from %s", host, port,
+        min_brightness, max_brightness, p->use_rms ? "rms" : "peak");
     return s;
 }
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lgtv-audio-cap",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "private": true,
   "description": "Captures audio on an LG webOS 5/6 TV and streams it out \u2014 HyperHDR first, plus raw UDP, TCP and HTTP.",
   "keywords": [

servicefiles/package.json

@@ -1,6 +1,6 @@
 {
   "id": "org.webosbrew.audiocap.service",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "Captures TV audio and streams it to HyperHDR and other receivers",
   "main": "audiocap-service"
 }