Merge pull request 'ffmpeg-v4l2-request-fourier: substitute H.264 IDCT 8×8 → daedalus-fourier' (#85) from claude-noether/marfrit-packages:noether/ffmpeg-fourier-idct8-daedalus into main

Reviewed-on: #85

arch/ffmpeg-v4l2-request-fourier/0004-h264-idct8-daedalus-fourier.patch

@@ -0,0 +1,107 @@
+From 1b286ddb4efaca26ec9b9e290e989fec77dc1c77 Mon Sep 17 00:00:00 2001
+From: Markus Fritsche <mfritsche@reauktion.de>
+Date: Fri, 22 May 2026 10:18:21 +0200
+Subject: [PATCH] avcodec/aarch64/h264dsp: route H.264 8x8 IDCT through
+ daedalus-fourier
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+H264DSPContext.idct8_add (called per 8x8 block from the High-profile
+intra-8x8-DCT decode path in h264_mb.c) now dispatches through
+daedalus_recipe_dispatch_h264_idct8 instead of ff_h264_idct8_add_neon.
+
+The recipe layer picks the substrate; for cycle 7 (H.264 IDCT 8x8)
+the recipe is CPU NEON, so this is effectively a NEON-to-NEON
+substitution layered on top of the cycle-6 IDCT 4x4 wiring.  Same
+pthread_once global context, same destructive-zero semantics; FFmpeg
+column-major 8x8 storage block[r + 8*c] matches daedalus's convention.
+
+Bulk path c->idct8_add4 (used for inter 8x8-DCT macroblocks) remains
+on the in-tree NEON .S code and will be batched through
+daedalus_recipe_dispatch_h264_idct8 with n_blocks>1 in a follow-up.
+
+Bit-exact against ff_h264_idct8_add_neon (daedalus-fourier cycle 7
+green).
+
+Refs reauktion/daedalus-v4l2#11 — substitution arc step 2 cycle 7.
+---
+ libavcodec/aarch64/h264_idct_daedalus.c   | 29 ++++++++++++++++-------
+ libavcodec/aarch64/h264dsp_init_aarch64.c |  3 ++-
+ 2 files changed, 23 insertions(+), 9 deletions(-)
+
+diff --git a/libavcodec/aarch64/h264_idct_daedalus.c b/libavcodec/aarch64/h264_idct_daedalus.c
+index 538d223..cbb98af 100644
+--- a/libavcodec/aarch64/h264_idct_daedalus.c
++++ b/libavcodec/aarch64/h264_idct_daedalus.c
+@@ -1,14 +1,16 @@
+ /*
+- * H.264 4x4 IDCT + add — daedalus-fourier substitution shim.
++ * H.264 4x4 / 8x8 IDCT + add — daedalus-fourier substitution shims.
+  *
+- * Routes H264DSPContext.idct_add through
+- * daedalus_recipe_dispatch_h264_idct4 instead of ff_h264_idct_add_neon.
+- * The recipe layer picks the substrate (CPU NEON by default for
+- * cycle 6; future cycles may dispatch to V3D opportunistically).
++ * Routes H264DSPContext.idct_add  → daedalus_recipe_dispatch_h264_idct4
++ *        H264DSPContext.idct8_add → daedalus_recipe_dispatch_h264_idct8
++ * instead of the in-tree ff_h264_idct{,8}_add_neon assembly.  The
++ * recipe layer picks the substrate (CPU NEON by default for cycles
++ * 6 + 7; future cycles may dispatch to V3D opportunistically).
+  *
+- * FFmpeg's 4x4 block memory layout matches daedalus's column-major
+- * convention: block[r + 4*c] = coefficient at (row r, col c).  Both
+- * sides destructively zero the block after the transform.
++ * FFmpeg's 4x4 and 8x8 block memory layouts match daedalus's
++ * column-major convention: block[r + N*c] = coefficient at
++ * (row r, col c) for N ∈ {4, 8}.  Both sides destructively zero the
++ * block after the transform.
+  *
+  * The library context is process-global and lazily initialised under
+  * pthread_once.  We pick the no-QPU constructor here because
+@@ -37,6 +39,7 @@ static void daedalus_ctx_init_once(void)
+ }
+ 
+ void ff_h264_idct_add_daedalus(uint8_t *dst, int16_t *block, int stride);
++void ff_h264_idct8_add_daedalus(uint8_t *dst, int16_t *block, int stride);
+ 
+ void ff_h264_idct_add_daedalus(uint8_t *dst, int16_t *block, int stride)
+ {
+@@ -47,3 +50,13 @@ void ff_h264_idct_add_daedalus(uint8_t *dst, int16_t *block, int stride)
+     daedalus_recipe_dispatch_h264_idct4(g_dctx, dst, (size_t)stride,
+                                         block, 1, &meta);
+ }
++
++void ff_h264_idct8_add_daedalus(uint8_t *dst, int16_t *block, int stride)
++{
++    static const daedalus_h264_block_meta meta = { .dst_off = 0 };
++
++    pthread_once(&g_dctx_once, daedalus_ctx_init_once);
++
++    daedalus_recipe_dispatch_h264_idct8(g_dctx, dst, (size_t)stride,
++                                        block, 1, &meta);
++}
+diff --git a/libavcodec/aarch64/h264dsp_init_aarch64.c b/libavcodec/aarch64/h264dsp_init_aarch64.c
+index b993df2..741e551 100644
+--- a/libavcodec/aarch64/h264dsp_init_aarch64.c
++++ b/libavcodec/aarch64/h264dsp_init_aarch64.c
+@@ -79,6 +79,7 @@ void ff_h264_idct_add8_neon(uint8_t **dest, const int *block_offset,
+                             const uint8_t nnzc[15 * 8]);
+ 
+ void ff_h264_idct8_add_neon(uint8_t *dst, int16_t *block, int stride);
++void ff_h264_idct8_add_daedalus(uint8_t *dst, int16_t *block, int stride);
+ void ff_h264_idct8_dc_add_neon(uint8_t *dst, int16_t *block, int stride);
+ void ff_h264_idct8_add4_neon(uint8_t *dst, const int *block_offset,
+                              int16_t *block, int stride,
+@@ -146,7 +147,7 @@ av_cold void ff_h264dsp_init_aarch64(H264DSPContext *c, const int bit_depth,
+         c->idct_add16intra = ff_h264_idct_add16intra_neon;
+         if (chroma_format_idc <= 1)
+             c->idct_add8   = ff_h264_idct_add8_neon;
+-        c->idct8_add       = ff_h264_idct8_add_neon;
++        c->idct8_add       = ff_h264_idct8_add_daedalus;
+         c->idct8_dc_add    = ff_h264_idct8_dc_add_neon;
+         c->idct8_add4      = ff_h264_idct8_add4_neon;
+     } else if (have_neon(cpu_flags) && bit_depth == 10) {
+-- 
+2.47.3
+

arch/ffmpeg-v4l2-request-fourier/PKGBUILD

@@ -24,7 +24,7 @@ _srcname=FFmpeg
 _version='8.1'
 _commit='b57fbbe50c9b2656fad86a1a7eeabfd2b2a50935'  # v4l2-request-n8.1 tip 2026-04-24
 pkgver=8.1.r123329.b57fbbe
-pkgrel=6   # pkgrel=6 — H.264 IDCT 4x4 daedalus-fourier substitution (2026-05-21)
+pkgrel=7   # pkgrel=7 — H.264 IDCT 8x8 daedalus-fourier substitution (cycle 7, 2026-05-22)
 epoch=2
 
 # daedalus-fourier pin — first kernel substitution in libavcodec
@@ -90,8 +90,9 @@ source=("git+https://github.com/Kwiboo/FFmpeg.git#commit=${_commit}"
         "daedalus-fourier-${_daedalus_fourier_commit}.tar.gz::https://git.reauktion.de/marfrit/daedalus-fourier/archive/${_daedalus_fourier_commit}.tar.gz"
         '0001-libudev-bypass-fallback.patch'
         '0002-nv15-to-p010-unpack.patch'
-        '0003-h264-idct4-daedalus-fourier.patch')
-sha256sums=('SKIP' 'SKIP' 'SKIP' 'SKIP' 'SKIP')
+        '0003-h264-idct4-daedalus-fourier.patch'
+        '0004-h264-idct8-daedalus-fourier.patch')
+sha256sums=('SKIP' 'SKIP' 'SKIP' 'SKIP' 'SKIP' 'SKIP')
 
 pkgver() {
   cd "${_srcname}"
@@ -105,6 +106,7 @@ prepare() {
   patch -Np1 -i "${srcdir}/0001-libudev-bypass-fallback.patch"
   patch -Np1 -i "${srcdir}/0002-nv15-to-p010-unpack.patch"
   patch -Np1 -i "${srcdir}/0003-h264-idct4-daedalus-fourier.patch"
+  patch -Np1 -i "${srcdir}/0004-h264-idct8-daedalus-fourier.patch"
 }
 
 build() {

debian/ffmpeg-v4l2-request-fourier/0004-h264-idct8-daedalus-fourier.patch

@@ -0,0 +1,107 @@
+From 1b286ddb4efaca26ec9b9e290e989fec77dc1c77 Mon Sep 17 00:00:00 2001
+From: Markus Fritsche <mfritsche@reauktion.de>
+Date: Fri, 22 May 2026 10:18:21 +0200
+Subject: [PATCH] avcodec/aarch64/h264dsp: route H.264 8x8 IDCT through
+ daedalus-fourier
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+H264DSPContext.idct8_add (called per 8x8 block from the High-profile
+intra-8x8-DCT decode path in h264_mb.c) now dispatches through
+daedalus_recipe_dispatch_h264_idct8 instead of ff_h264_idct8_add_neon.
+
+The recipe layer picks the substrate; for cycle 7 (H.264 IDCT 8x8)
+the recipe is CPU NEON, so this is effectively a NEON-to-NEON
+substitution layered on top of the cycle-6 IDCT 4x4 wiring.  Same
+pthread_once global context, same destructive-zero semantics; FFmpeg
+column-major 8x8 storage block[r + 8*c] matches daedalus's convention.
+
+Bulk path c->idct8_add4 (used for inter 8x8-DCT macroblocks) remains
+on the in-tree NEON .S code and will be batched through
+daedalus_recipe_dispatch_h264_idct8 with n_blocks>1 in a follow-up.
+
+Bit-exact against ff_h264_idct8_add_neon (daedalus-fourier cycle 7
+green).
+
+Refs reauktion/daedalus-v4l2#11 — substitution arc step 2 cycle 7.
+---
+ libavcodec/aarch64/h264_idct_daedalus.c   | 29 ++++++++++++++++-------
+ libavcodec/aarch64/h264dsp_init_aarch64.c |  3 ++-
+ 2 files changed, 23 insertions(+), 9 deletions(-)
+
+diff --git a/libavcodec/aarch64/h264_idct_daedalus.c b/libavcodec/aarch64/h264_idct_daedalus.c
+index 538d223..cbb98af 100644
+--- a/libavcodec/aarch64/h264_idct_daedalus.c
++++ b/libavcodec/aarch64/h264_idct_daedalus.c
+@@ -1,14 +1,16 @@
+ /*
+- * H.264 4x4 IDCT + add — daedalus-fourier substitution shim.
++ * H.264 4x4 / 8x8 IDCT + add — daedalus-fourier substitution shims.
+  *
+- * Routes H264DSPContext.idct_add through
+- * daedalus_recipe_dispatch_h264_idct4 instead of ff_h264_idct_add_neon.
+- * The recipe layer picks the substrate (CPU NEON by default for
+- * cycle 6; future cycles may dispatch to V3D opportunistically).
++ * Routes H264DSPContext.idct_add  → daedalus_recipe_dispatch_h264_idct4
++ *        H264DSPContext.idct8_add → daedalus_recipe_dispatch_h264_idct8
++ * instead of the in-tree ff_h264_idct{,8}_add_neon assembly.  The
++ * recipe layer picks the substrate (CPU NEON by default for cycles
++ * 6 + 7; future cycles may dispatch to V3D opportunistically).
+  *
+- * FFmpeg's 4x4 block memory layout matches daedalus's column-major
+- * convention: block[r + 4*c] = coefficient at (row r, col c).  Both
+- * sides destructively zero the block after the transform.
++ * FFmpeg's 4x4 and 8x8 block memory layouts match daedalus's
++ * column-major convention: block[r + N*c] = coefficient at
++ * (row r, col c) for N ∈ {4, 8}.  Both sides destructively zero the
++ * block after the transform.
+  *
+  * The library context is process-global and lazily initialised under
+  * pthread_once.  We pick the no-QPU constructor here because
+@@ -37,6 +39,7 @@ static void daedalus_ctx_init_once(void)
+ }
+ 
+ void ff_h264_idct_add_daedalus(uint8_t *dst, int16_t *block, int stride);
++void ff_h264_idct8_add_daedalus(uint8_t *dst, int16_t *block, int stride);
+ 
+ void ff_h264_idct_add_daedalus(uint8_t *dst, int16_t *block, int stride)
+ {
+@@ -47,3 +50,13 @@ void ff_h264_idct_add_daedalus(uint8_t *dst, int16_t *block, int stride)
+     daedalus_recipe_dispatch_h264_idct4(g_dctx, dst, (size_t)stride,
+                                         block, 1, &meta);
+ }
++
++void ff_h264_idct8_add_daedalus(uint8_t *dst, int16_t *block, int stride)
++{
++    static const daedalus_h264_block_meta meta = { .dst_off = 0 };
++
++    pthread_once(&g_dctx_once, daedalus_ctx_init_once);
++
++    daedalus_recipe_dispatch_h264_idct8(g_dctx, dst, (size_t)stride,
++                                        block, 1, &meta);
++}
+diff --git a/libavcodec/aarch64/h264dsp_init_aarch64.c b/libavcodec/aarch64/h264dsp_init_aarch64.c
+index b993df2..741e551 100644
+--- a/libavcodec/aarch64/h264dsp_init_aarch64.c
++++ b/libavcodec/aarch64/h264dsp_init_aarch64.c
+@@ -79,6 +79,7 @@ void ff_h264_idct_add8_neon(uint8_t **dest, const int *block_offset,
+                             const uint8_t nnzc[15 * 8]);
+ 
+ void ff_h264_idct8_add_neon(uint8_t *dst, int16_t *block, int stride);
++void ff_h264_idct8_add_daedalus(uint8_t *dst, int16_t *block, int stride);
+ void ff_h264_idct8_dc_add_neon(uint8_t *dst, int16_t *block, int stride);
+ void ff_h264_idct8_add4_neon(uint8_t *dst, const int *block_offset,
+                              int16_t *block, int stride,
+@@ -146,7 +147,7 @@ av_cold void ff_h264dsp_init_aarch64(H264DSPContext *c, const int bit_depth,
+         c->idct_add16intra = ff_h264_idct_add16intra_neon;
+         if (chroma_format_idc <= 1)
+             c->idct_add8   = ff_h264_idct_add8_neon;
+-        c->idct8_add       = ff_h264_idct8_add_neon;
++        c->idct8_add       = ff_h264_idct8_add_daedalus;
+         c->idct8_dc_add    = ff_h264_idct8_dc_add_neon;
+         c->idct8_add4      = ff_h264_idct8_add4_neon;
+     } else if (have_neon(cpu_flags) && bit_depth == 10) {
+-- 
+2.47.3
+

debian/ffmpeg-v4l2-request-fourier/build-deb.sh

@@ -33,13 +33,11 @@ FFMPEG_VERSION=8.1
 # epoch 2 matches Debian's stock ffmpeg (currently 7:7.1.x in trixie);
 # +rfourier suffix to avoid colliding with upstream/Debian rebuilds.
 PKGVER=2:${FFMPEG_VERSION}+rfourier+gb57fbbe
-PKGREL=6  # pkgrel=6 — drop --enable-libxml2 to avoid runner/target libxml2
-          # SOVERSION skew (runner has libxml2 ≥ 2.14 = SONAME 16; trixie
-          # has 2.12 = SONAME 2; -5 .deb dlopens libavformat → fails on
-          # "libxml2.so.16: cannot open shared object").  Neither the
-          # daedalus-v4l2 daemon (direct AVPacket feed) nor mpv-fourier
-          # nor firefox-fourier consumers need FFmpeg's DASH demuxer.
-          # (2026-05-21)
+PKGREL=7  # pkgrel=7 — H.264 IDCT 8x8 daedalus-fourier substitution
+          # (cycle 7).  Stacks on top of cycle-6 IDCT 4x4 (PR #76) and
+          # the libxml2-drop ABI-skew workaround (PR #78).  Wires
+          # H264DSPContext.idct8_add through
+          # daedalus_recipe_dispatch_h264_idct8.  (2026-05-22)
 
 # daedalus-fourier pin — first kernel substitution in libavcodec (cycle 6
 # H.264 IDCT 4x4).  Same SHA as the daedalus-v4l2 daemon already ships
@@ -69,6 +67,7 @@ fi
 patch -Np1 -i "$HERE/0001-libudev-bypass-fallback.patch"
 patch -Np1 -i "$HERE/0002-nv15-to-p010-unpack.patch"
 patch -Np1 -i "$HERE/0003-h264-idct4-daedalus-fourier.patch"
+patch -Np1 -i "$HERE/0004-h264-idct8-daedalus-fourier.patch"
 
 # --- daedalus-fourier: fetch + build static .a with PIC, install to a
 # per-build prefix; libavcodec.so links it into the shared object so

debian/ffmpeg-v4l2-request-fourier/debian/changelog

@@ -1,3 +1,21 @@
+ffmpeg-v4l2-request-fourier (2:8.1+rfourier+gb57fbbe-7) bookworm trixie; urgency=medium
+
+  * Add 0004-h264-idct8-daedalus-fourier.patch — H264DSPContext.idct8_add
+    (per-block 8x8 IDCT, called from the High-profile intra-8x8-DCT
+    macroblock path in libavcodec/h264_mb.c) now dispatches through
+    daedalus_recipe_dispatch_h264_idct8 instead of
+    ff_h264_idct8_add_neon.  Cycle 7 of the daedalus-v4l2#11 step 2
+    substitution arc — NEON-by-recipe, same pthread_once context the
+    cycle-6 IDCT 4x4 shim already owns.
+  * Bit-exact against ff_h264_idct8_add_neon (daedalus-fourier cycle 7
+    green; FFmpeg 8x8 block storage block[r + 8*c] matches daedalus
+    column-major convention).
+  * Bulk c->idct8_add4 (inter 8x8-DCT macroblocks) stays on the
+    in-tree NEON .S code; batched substitution lands later.
+  * No SONAME change, no Depends change.
+
+ -- Markus Fritsche <mfritsche@reauktion.de>  Fri, 22 May 2026 10:30:00 +0000
+
 ffmpeg-v4l2-request-fourier (2:8.1+rfourier+gb57fbbe-6) bookworm trixie; urgency=medium
 
   * Drop --enable-libxml2 + libxml2 Depends — the Gitea