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#if 0  // self-compiling code: chmod +x this file and run it like a script
BINARY=vaapi_egl_interop_example
gcc -std=c99 -Wall -Wextra -pedantic -Werror -g -fsanitize=address -o $BINARY $0 \
    `pkg-config libavcodec libavformat libavutil libva gl egl libdrm --cflags --libs` \
    -lX11 -lva-x11 -lva-drm || exit 1
test "$1" = "--compile-only" && exit 0
exec env ASAN_OPTIONS=fast_unwind_on_malloc=0 ./$BINARY $*
#endif  /*

Minimal example application for hardware video decoding on Linux and display

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H.264参数集处理

[toc]

摘要

介绍H.264参数集与几种字节流格式的关系，以及in-band/out-of-band传递参数集的方式与容器格式、传输协议的关系，描述MP4格式、FLV格式处理参数集的一些兼容性问题。

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=================================================================
==28728==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 528 byte(s) in 2 object(s) allocated from:
    #0 0x5648c5aae5e0 in __interceptor_posix_memalign (/mnt/src/src/ffmpeg-build/build/ffmpeg/ffmpeg+0x5d85e0)
    #1 0x5648c8b9532a in av_malloc src/libavutil/mem.c:87
    #2 0x5648c63daa09 in avio_alloc_context src/libavformat/aviobuf.c:140
    #3 0x5648c63dfc8b in ffio_fdopen src/libavformat/aviobuf.c:1002
    #4 0x5648c63e1287 in ffio_open_whitelist src/libavformat/aviobuf.c:1171
    #5 0x5648c66cfaca in io_open_default src/libavformat/options.c:124

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HLS协议的核心设计至少包括三点：大规模分发、多设备兼容和码率自适应。码率自适应包括自适应算法设计以及如何实现切换。HLS协议本身不负责自适应算法，它描述的是如何实现切换。一个基础问题：从a.m3u8切换到b.m3u8时，如何在b.m3u8中找到要播放的切片？

最简单、看起来最合理的方案：在b.m3u8中找匹配的sequence number。可能多数播放器是这么做的。

但是，HLS草案第9版（2012年9月）新增了这么一段描述：

https://datatracker.ietf.org/doc/html/draft-pantos-http-live-streaming-09

used to synchronize the old and new timelines precisely. A client MUST NOT assume that segments with the same media sequence number in

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diff --git a/libavcodec/aarch64/videodsp.S b/libavcodec/aarch64/videodsp.S
index 24067cc2af..fe2da0658e 100644
--- a/libavcodec/aarch64/videodsp.S
+++ b/libavcodec/aarch64/videodsp.S
@@ -19,10 +19,11 @@
 #include "libavutil/aarch64/asm.S"

 function ff_prefetch_aarch64, export=1
+1:
         subs            w2,  w2,  #2

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如何找到虚函数地址

摘要

关于虚函数的实现、虚函数表的含义，已经有很多资料介绍。这里分析一个实际问题：虚函数寻址的编译实现，或者说如何找到虚函数的地址。弄清楚这一问题，有助于理解分析通过野指针调用虚函数时的行为表现。

• 注意：本文分析虚函数具体实现，具体实现与编译器有关。测试环境包括Android + armv8 + clang, macOS + x64 + clang.

虚函数解引用的汇编

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How to build VLC on Android

• This is an introduction about build VLC on Android natively, not cross build VLC for Android
• It's pretty useless, just for fun.

Prepare

1. Install termux from F-Droid or Google play on Android device

Termux is an Android terminal emulator and Linux environment app that works directly with no rooting or setup required. A minimal base system is installed automatically - additional packages are available using the APT package manager.

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diff --git a/modules/video_output/opengl/interop.c b/modules/video_output/opengl/interop.c
index 96d548519e..6ded931189 100644
--- a/modules/video_output/opengl/interop.c
+++ b/modules/video_output/opengl/interop.c
@@ -321,6 +321,24 @@ interop_rgb_base_init(struct vlc_gl_interop *interop, GLenum tex_target,
             break;

         case VLC_CODEC_RGB32:
+            if (interop->fmt_in.i_rmask == 0x00ff0000
+                    && interop->fmt_in.i_gmask == 0x0000ff00

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#include <stdio.h>
#include <stdlib.h>

#include <unordered_map>

static std::unordered_map<int, std::string> MacintoshLanguageCodes{
    {0, "English"},       {1, "French"},
    {2, "German"},        {3, "Italian"},
    {4, "Dutch"},         {5, "Swedish"},
    {6, "Spanish"},       {7, "Danish"},