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/msmpeg4.h

@@ -0,0 +1,41 @@
+/*
+ * MSMPEG4 backend for encoder and decoder
+ * copyright (c) 2007 Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * 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_MSMPEG4_H
+#define AVCODEC_MSMPEG4_H
+
+#include <stdint.h>
+
+#include "mpegvideo.h"
+
+#define II_BITRATE 128*1024
+#define MBAC_BITRATE 50*1024
+
+#define DC_MAX 119
+
+void ff_msmpeg4_common_init(MpegEncContext *s);
+int ff_msmpeg4_coded_block_pred(MpegEncContext * s, int n,
+                                uint8_t **coded_block_ptr);
+
+int ff_msmpeg4_pred_dc(MpegEncContext *s, int n,
+                       int16_t **dc_val_ptr, int *dir_ptr);
+
+#endif /* AVCODEC_MSMPEG4_H */