obs-ndi-output.cpp

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已于 2022-04-08 10:07:59 修改 · 808 阅读

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#ndi推流

于 2022-04-07 18:18:40 首次发布

本文档分析了obs-ndi推流代码，针对音视频延迟、不同步和卡顿现象，提供了可能的解决方案和代码片段，探讨如何调整设置以提高性能并确保实时同步。

ndi推流，音视频延迟大，不同步，卡顿。参考obs-ndi推流代码。

https://github.com/Palakis/obs-ndi/blob/master/src/obs-ndi-output.cpp

/*
obs-ndi
Copyright (C) 2016-2018 Stéphane Lepin <steph name of author
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; If not, see <https://www.gnu.org/licenses/>
*/

#include <obs-module.h>
#include <util/platform.h>
#include <util/threading.h>
#include <util/profiler.h>
#include <util/circlebuf.h>

#include "obs-ndi.h"

static FORCE_INLINE uint32_t min_uint32(uint32_t a, uint32_t b)
{
return a < b ? a : b;
}

typedef void (*uyvy_conv_function)(uint8_t* input[], uint32_t in_linesize[],
uint32_t start_y, uint32_t end_y,
uint8_t* output, uint32_t out_linesize);

static void convert_i444_to_uyvy(uint8_t* input[], uint32_t in_linesize[],
                       uint32_t start_y, uint32_t end_y,
                       uint8_t* output, uint32_t out_linesize)
{
   uint8_t* _Y;
   uint8_t* _U;
   uint8_t* _V;
   uint8_t* _out;
   uint32_t width = min_uint32(in_linesize[0], out_linesize);
   for (uint32_t y = start_y; y < end_y; ++y) {
       _Y = input[0] + ((size_t)y * (size_t)in_linesize[0]);
       _U = input[1] + ((size_t)y * (size_t)in_linesize[1]);
       _V = input[2] + ((size_t)y * (size_t)in_linesize[2]);

_out = output + ((size_t)y * (size_t)out_linesize);

       for (uint32_t x = 0; x < width; x += 2) {
           // Quality loss here. Some chroma samples are ignored.
           *(_out++) = *(_U++); _U++;
           *(_out++) = *(_Y++);
           *(_out++) = *(_V++); _V++;
           *(_out++) = *(_Y++);
       }
   }
}

struct ndi_output
{
   obs_output_t *output;
   const char* ndi_name;
   bool uses_video;
   bool uses_audio;

bool started;
NDIlib_send_instance_t ndi_sender;