webm

How to keep transparency when scale webm file with ffmpeg

由 Deadly 提交于 2021-02-20 00:26:10
问题 I'm using ffmpeg to scale my WEBM file, by using below command: ffmpeg -i in.webm -c:v libvpx -vf scale=100:100 out.webm The output has correct resolution as I expected but the problem is transparency become black background. Could someone give me a solution for this. Thank you so much. Below is the log of the operation: ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 7.2.0 (GCC) configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib -

How to keep transparency when scale webm file with ffmpeg

由 笑着哭i 提交于 2021-02-20 00:22:41
问题 I'm using ffmpeg to scale my WEBM file, by using below command: ffmpeg -i in.webm -c:v libvpx -vf scale=100:100 out.webm The output has correct resolution as I expected but the problem is transparency become black background. Could someone give me a solution for this. Thank you so much. Below is the log of the operation: ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 7.2.0 (GCC) configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib -

How to keep transparency when scale webm file with ffmpeg

由 微笑、不失礼 提交于 2021-02-20 00:21:19
问题 I'm using ffmpeg to scale my WEBM file, by using below command: ffmpeg -i in.webm -c:v libvpx -vf scale=100:100 out.webm The output has correct resolution as I expected but the problem is transparency become black background. Could someone give me a solution for this. Thank you so much. Below is the log of the operation: ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 7.2.0 (GCC) configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib -

How to keep transparency when scale webm file with ffmpeg

由 六眼飞鱼酱① 提交于 2021-02-20 00:19:59
问题 I'm using ffmpeg to scale my WEBM file, by using below command: ffmpeg -i in.webm -c:v libvpx -vf scale=100:100 out.webm The output has correct resolution as I expected but the problem is transparency become black background. Could someone give me a solution for this. Thank you so much. Below is the log of the operation: ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 7.2.0 (GCC) configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib -

ffmpeg, dash manifest cannot be created due to unspecified pixel format

由 社会主义新天地 提交于 2021-02-18 17:37:13
问题 I am using ffmpeg 2.8 on OSX. I try to convert a short mp4 video to webm for adaptive streaming like suggested here http://wiki.webmproject.org/adaptive-streaming/instructions-to-playback-adaptive-webm-using-dash like this: VP9_DASH_PARAMS="-tile-columns 6 -frame-parallel 1" ffmpeg -i t2.mp4 -c:v libvpx-vp9 -s 160x90 -b:v 250k -keyint_min 150 -g 150 ${VP9_DASH_PARAMS} -an -f webm -dash 1 video_160x90_250k.webm ffmpeg -i t2.mp4 -c:a libvorbis -b:a 128k -vn -f webm -dash 1 audio_128k.webm

Explanation on Integer to Array

由 家住魔仙堡 提交于 2021-02-08 08:40:22
问题 Please Help I know that you are reading this, and I would appreciate a comment if do not have an answer because I feel that I am alone in trying to figure this out. How Does this Work? I have thoroughly read this document. It mentions an element called TimestampScale. I have downloaded probably thirty WebM example files and seen that the values following the HEX { 0x2AD7B1 or 2A D7 B1 or ['2A','D7','B1'] } or NON-HEX integers { 42 215 177 or [42, 215, 177] } are always the same: HEX {

html总结（二）

由 99封情书 提交于 2021-02-07 12:15:23
表格 table （会使用） 表格由 <table> 标签来定义。每个表格均有若干行（由 <tr> 标签定义），每行被分割为若干单元格（由 <td> 标签定义）。字母 td 指表格数据（table data），即数据单元格的内容。数据单元格可以包含文本、图片、列表、段落、表单、水平线、表格等等。 <table> <tr> <td> </td> </tr> </table> 注意： tr标签只能放td标签，td标签可以放其他元素 表格属性 属性名 含义 常用属性值 border 设置表格的边框（默认border=”0”无边框） 像素值 cellspacing 设置单元格与单元格之间的空白间距 像素值（默认为2像素） cellpadding 设置单元格内容与单元格边框之间的空白距离 像素值（默认为1像素） width 设置表格的宽度 像素值 height 设置表格的高度 像素值 align 设置表格在网页中的水平对齐方式 left、right、center 表头标签 表头一般位于表格的第一行或第一列，其文本加粗居中 表格结构 表格可以划分为表头和主体，所以有 <thead></thead> 标签和 <tbody></tbody> 表格标题标签 caption <table> <caption>标题</caption> </table> 合并单元格 跨行合并：rowspan 跨列合并

nodejs ffmpeg play video at specific time and stream it to client

由 浪尽此生 提交于 2021-02-07 10:30:00
问题 I'm trying to make a basic online video editor with nodeJS and ffmpeg. To do this I need 2 steps: set the in-and-out times of the videos from the client, which requires the client to view the video at specific times, and switch the position of the video. Meaning, if a single video is used as an input, and split it into smaller parts, it needs to replay from the starting time of the next edited segment, if that makes sense. send the input-output data to nodejs and export it with ffmpeg as a

FFmpeg live streaming webm video to multiple http clients over Nodejs

由 笑着哭i 提交于 2021-02-07 09:02:35
问题 I am trying to share a live stream of my screen over an ExpressJS server. I cannot save ffmpeg output to a file or start more than one ffmpeg instance for performance reason. My current solution is to pipe ffmpeg's stdout and stream it to each connected client. index.js const express = require('express'); const app = express(); const request = require('request'); const FFmpeg = require('./FFmpeg'); const APP_PORT = 3500; app.get('/stream', function (req, res) { const recorder = FFmpeg

Splitting webm video to png with transparency

由 a 夏天 提交于 2021-02-07 08:11:41
问题 I need to split a webm encoded video into png frames, without losing transparency. I use the following ffmpeg command: ffmpeg -i dancer1.webm -pix_fmt rgba frames/%04d.png This produces a directory of pngs, but why is each output frame is missing transparency? I have used this example video, which contains an alpha channel. See it playing over a background here. Here's an example output frame from ffmpeg: ffmpeg produces the following output when it runs: ffmpeg version N-60294-g549f052
订阅 webm