diff --git a/tools/audio_fix.py b/tools/audio_fix.py
new file mode 100644
index 0000000..0f393ac
--- /dev/null
+++ b/tools/audio_fix.py
@@ -0,0 +1,49 @@
+"""Patches deltacast-bridge audio_thread to follow SDK Sample_RXAudio.cpp:
+- Set Mode/BufferFormat on BOTH pAudioChannels[0] AND [1] (stereo pair)
+- Get/Set VHD_SDI_SP_INTERFACE on the audio stream
+Without these, VHD_SlotExtractAudio returns 0 samples (silent capture)."""
+path = 'services/capture/deltacast-bridge/main.c'
+with open(path) as f:
+    s = f.read()
+
+old = """    ULONG r = VHD_OpenStreamHandle(ps->board, rx_streamtype(ps->port),
+                                   VHD_SDI_STPROC_DISJOINED_ANC,
+                                   NULL, &stream, NULL);
+    if (r == VHDERR_NOERROR) {
+        VHD_SetStreamProperty(stream, VHD_SDI_SP_VIDEO_STANDARD,    ps->video_std);
+        VHD_SetStreamProperty(stream, VHD_SDI_SP_CLOCK_SYSTEM,      ps->clock_div);
+        VHD_SetStreamProperty(stream, VHD_CORE_SP_TRANSFER_SCHEME,  VHD_TRANSFER_SLAVED);
+
+        ai.pAudioGroups[0].pAudioChannels[0].Mode         = VHD_AM_STEREO;
+        ai.pAudioGroups[0].pAudioChannels[0].BufferFormat = VHD_AF_16;
+        ai.pAudioGroups[0].pAudioChannels[0].pData        = buf;"""
+
+new = """    ULONG r = VHD_OpenStreamHandle(ps->board, rx_streamtype(ps->port),
+                                   VHD_SDI_STPROC_DISJOINED_ANC,
+                                   NULL, &stream, NULL);
+    if (r == VHDERR_NOERROR) {
+        /* Per Deltacast SDK Sample_RXAudio.cpp: VHD_SDI_SP_INTERFACE must be
+         * propagated to the audio stream, otherwise VHD_SlotExtractAudio
+         * returns 0 samples (silent capture). */
+        ULONG iface = 0;
+        VHD_GetStreamProperty(stream, VHD_SDI_SP_INTERFACE, &iface);
+
+        VHD_SetStreamProperty(stream, VHD_SDI_SP_VIDEO_STANDARD,    ps->video_std);
+        VHD_SetStreamProperty(stream, VHD_SDI_SP_CLOCK_SYSTEM,      ps->clock_div);
+        VHD_SetStreamProperty(stream, VHD_CORE_SP_TRANSFER_SCHEME,  VHD_TRANSFER_SLAVED);
+        VHD_SetStreamProperty(stream, VHD_SDI_SP_INTERFACE,         iface);
+
+        /* Configure BOTH channels of the stereo pair (group 0). The actual PCM
+         * samples land in pAudioChannels[0].pData (packed L/R s16le). Channel
+         * [1] must declare Mode+BufferFormat so the SDK recognizes the pair. */
+        ai.pAudioGroups[0].pAudioChannels[0].Mode         = VHD_AM_STEREO;
+        ai.pAudioGroups[0].pAudioChannels[0].BufferFormat = VHD_AF_16;
+        ai.pAudioGroups[0].pAudioChannels[0].pData        = buf;
+        ai.pAudioGroups[0].pAudioChannels[1].Mode         = VHD_AM_STEREO;
+        ai.pAudioGroups[0].pAudioChannels[1].BufferFormat = VHD_AF_16;"""
+
+assert old in s, 'Old block not found'
+s = s.replace(old, new, 1)
+with open(path, 'w') as f:
+    f.write(s)
+print('PATCHED OK')