mp4 | 易学教程

How to tag or add metadata to a video file with GStreamer?

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问题 I would like to add metadatas to an MP4 video file with GStreamer: How to do it while recording the file? How to do it when the file is already recorded? Is that possible to check these modifications with GStreamer? For example, with FFmpeg, I can add a title to my video with this command line: ffmpeg -i in.mp4 -metadata title="my title" out.mp4 And then, I check the result with mediainfo: mediainfo out.mp4 回答1: I found a way to do it with a debug plugin: taginject For example, in order to

WebGL/Three.js深度学习课程详解

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课程介绍: 适用于对WebGL、Three.js等3D技术感兴趣，却不知道如何入门的同学，课程带领大家深入理解WebGL的原理。课程目录: ├─01-基础部分 │ 01-WebGL与three.js的基础、与opengl的关系.mp4 │ 02-编写第一个three.js程序.mp4 │ 03-three.js程序框架，绘制一条直线.mp4 │ 04-三维世界的组成(点、线).mp4 │ 05-坐标系的秘密（世界坐标、本地坐标）.mp4 │ 06-three.js让场景动起来的两种方法.mp4 │ 07-帧循环、游戏循环、渲染循环需要知道的深入意义.mp4 │ 08-three.js（WebGL）相机的工作原理，适用于任何一种3D编程方法.mp4 │ 09-正投影和透视投影相机的实践.mp4 │ 10-深入浅出WebGL中相机的三个向量参数.mp4 │ 13-光的初体验环境光.mp4 │ 14-光的初体验环境光2.mp4 │ 15-光的初体验点光源.mp4 │ 16-纹理一种让模型美丽的特殊技能.mp4 │ 17-纹理基础篇:three.js为物体加上皮肤，让世界还原真实.mp4 │ 18-纹理基础篇:纹理的重复与纹理的回环以及纹理偏移.mp4 │ 19-自定义绘制一个彩色三角形，了解geometry的结构.mp4 │ 20-geometry中face及face中的值的介绍

FFmpeg video filters corrupt mp4 file

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问题 I am trying to add visual filters to mp4 files using FFmpeg . I have tried many filters, but 4 of them worked out of which only 1 worked worked perfectly. I am using them in an Android application , but I tried the same command lines on windows cmd using FFmpeg and the result is same. With 3 filters the .mp4 is unplayable by many players and also Androids mediaplayer . I can still play the "corrupt" files on VLC and players that have many codex`s, but I need them to work perfectly. The only

conversion from mp3 to ogg using php

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问题 I want to convert mp3 file to ogg. I tried the following code exec("/usr/local/bin/ffmpeg -i 1.mp4 -vcodec libtheora -acodec libvorbis testjohn4545454.ogg",$output); var_dump($output); But it does not convert the file and it only returns array(0) { } and it only takes a little execution time. But the conversion is success when using ssh command. Please give me solution. 回答1: Funny thing here, you want to execute this in it's own process and in the background , otherwise your PHP script will

conversion from mp3 to ogg using php

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Sync Audio/Video in MP4 using AutoGen FFmpeg library

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问题 I'm currently having problems making my audio and video streams stay synced. These are the AVCodecContexts I'm using: For Video: AVCodec* videoCodec = ffmpeg.avcodec_find_encoder(AVCodecID.AV_CODEC_ID_H264) AVCodecContext* videoCodecContext = ffmpeg.avcodec_alloc_context3(videoCodec); videoCodecContext->bit_rate = 400000; videoCodecContext->width = 1280; videoCodecContext->height = 720; videoCodecContext->gop_size = 12; videoCodecContext->max_b_frames = 1; videoCodecContext->pix_fmt =

Sync Audio/Video in MP4 using AutoGen FFmpeg library

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combine multiple mp4 videos and images

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问题 so I have a folder of images, 1/20 named *.png and a folder of mp4's named *.mp4 . I want to create a video in this order: 1.png for 3 sec 1.mp4 2.png for 3 sec 3.mp4 etc Is there a way I can display each png for 3 seconds and then show the respective mp4 using ffmpeg ? I know I can convert each picture to a 3 second video invididually using this command and the framerate differences will be a problem (1/3 vs 60), but I'm not very experienced with command line video editing: ffmpeg -r 1/3 -i

MP4文件格式总结

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mp4文件作为视频监控的主流媒体文件，框架结构也不算复杂，主要由一系列的box组成，这里简单解析一下。查看mp4文件的软件：MP4 Reader. 1.mp4文件的总体结构 2.各组成分析 ftyp ：file type box 存储文件类型 mdat ：media data box 存储媒体的具体内容 moov：movie box 存储媒体的信息这三个是一个MP4文件的必要信息，必须包含这些内容。一些文件中也会含有JCOK自定义信息，用来判断mp4文件的完整性。 3.moov box分析 mvhd：movie heafer box 主要描述time scale时间单元数 duration时间长度 rate播放速率 volume播放音量等信息。 trak：track box 一般包含video trak, audia trak 4.track box分析 tkhd：track header box 描述一些track信息，包含播放标志flag, 大小size,类型type，视频宽高w h等。 media：media box 描述media的起始偏移start offset, 大小size，类型type 5.media box 分析 mdhd：media header box 描述整个movie的特性，主要时间片间隔time scale，持续时间duration。 hdlr：

overwriting mp4/wmv video's audio content with a new audio in C#

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问题 I have a video clip and an audio clip. I want to place the audio over a section of the video. The starting point of both match, but the video is slightly longer. I want to do this in C# preferably. Does anybody know how I can do this ? I want to batch up a huge bunch of short ( 10 -12 min clips), and so need this to be in code. Thnx for the help. -egon 回答1: Your requirements is a quite specific. And I can see only a one way how to solve it. In my opinion, you should follow in the way of using