FFmpeg 7.1 + cuframes input demuxer

Snapshot FFmpeg n7.1 (release tag) с применённым patch'ем для cuframes
input format. Используется как FFMPEG_REPO_OVERRIDE в NickM-27/FFmpeg-Builds
fork для статической сборки patched binary под Frigate (Debian 12 / glibc 2.36).

Apply changes:
  + libavformat/cuframesdec.c (новый — реализация демуксера)
  M libavformat/Makefile (CONFIG_CUFRAMES_DEMUXER target)
  M libavformat/allformats.c (extern declaration)
  M configure (--enable-libcuframes option + dep check)

Patch source: https://git.goldix.org/gx/cuframes (filter/ffmpeg-7.1-cuframes-demuxer.patch)

History сброшена (snapshot вместо fork) потому что upstream shallow clone
не позволял push в gitea. Полная история FFmpeg — на github.com/FFmpeg/FFmpeg n7.1.

libavcodec/lpc.h

@@ -0,0 +1,118 @@
+/*
+ * LPC utility code
+ * Copyright (c) 2006  Justin Ruggles <justin.ruggles@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_LPC_H
+#define AVCODEC_LPC_H
+
+#include <stdint.h>
+#include <stddef.h>
+#include "libavutil/lls.h"
+
+#define ORDER_METHOD_EST     0
+#define ORDER_METHOD_2LEVEL  1
+#define ORDER_METHOD_4LEVEL  2
+#define ORDER_METHOD_8LEVEL  3
+#define ORDER_METHOD_SEARCH  4
+#define ORDER_METHOD_LOG     5
+
+#define MIN_LPC_ORDER        1
+#define MAX_LPC_ORDER       32
+
+/**
+ * LPC analysis type
+ */
+enum FFLPCType {
+    FF_LPC_TYPE_DEFAULT     = -1, ///< use the codec default LPC type
+    FF_LPC_TYPE_NONE        =  0, ///< do not use LPC prediction or use all zero coefficients
+    FF_LPC_TYPE_FIXED       =  1, ///< fixed LPC coefficients
+    FF_LPC_TYPE_LEVINSON    =  2, ///< Levinson-Durbin recursion
+    FF_LPC_TYPE_CHOLESKY    =  3, ///< Cholesky factorization
+    FF_LPC_TYPE_NB              , ///< Not part of ABI
+};
+
+typedef struct LPCContext {
+    int blocksize;
+    int max_order;
+    enum FFLPCType lpc_type;
+    double *windowed_buffer;
+    double *windowed_samples;
+
+    /**
+     * Apply a Welch window to an array of input samples.
+     * The output samples have the same scale as the input, but are in double
+     * sample format.
+     * @param data    input samples
+     * @param len     number of input samples
+     * @param w_data  output samples
+     */
+    void (*lpc_apply_welch_window)(const int32_t *data, ptrdiff_t len,
+                                   double *w_data);
+    /**
+     * Perform autocorrelation on input samples with delay of 0 to lag.
+     * @param data  input samples.
+     *              constraints: no alignment needed, but must have at
+     *              least lag*sizeof(double) valid bytes preceding it, and
+     *              size must be at least (len+1)*sizeof(double) if data is
+     *              16-byte aligned or (len+2)*sizeof(double) if data is
+     *              unaligned.
+     * @param len   number of input samples to process
+     * @param lag   maximum delay to calculate
+     * @param autoc output autocorrelation coefficients.
+     *              constraints: array size must be at least lag+1.
+     */
+    void (*lpc_compute_autocorr)(const double *data, ptrdiff_t len, int lag,
+                                 double *autoc);
+
+    // TODO: these should be allocated to reduce ABI compatibility issues
+    LLSModel lls_models[2];
+} LPCContext;
+
+
+/**
+ * Calculate LPC coefficients for multiple orders
+ */
+int ff_lpc_calc_coefs(LPCContext *s,
+                      const int32_t *samples, int blocksize, int min_order,
+                      int max_order, int precision,
+                      int32_t coefs[][MAX_LPC_ORDER], int *shift,
+                      enum FFLPCType lpc_type, int lpc_passes,
+                      int omethod, int min_shift, int max_shift, int zero_shift);
+
+int ff_lpc_calc_ref_coefs(LPCContext *s,
+                          const int32_t *samples, int order, double *ref);
+
+double ff_lpc_calc_ref_coefs_f(LPCContext *s, const float *samples, int len,
+                               int order, double *ref);
+
+/**
+ * Initialize LPCContext.
+ */
+int ff_lpc_init(LPCContext *s, int blocksize, int max_order,
+                enum FFLPCType lpc_type);
+void ff_lpc_init_riscv(LPCContext *s);
+void ff_lpc_init_x86(LPCContext *s);
+
+/**
+ * Uninitialize LPCContext.
+ */
+void ff_lpc_end(LPCContext *s);
+
+#endif /* AVCODEC_LPC_H */