PHP-FFMpeg/PHP-FFMpeg

Width not divisible by 2 when padding an h264 video

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#643 创建于 2019年4月17日

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 (1 评论) (1 反应) (0 负责人)PHP (4,641 star) (915 fork)batch import
bughelp wanted

描述

Q A
Bug? yes
New Feature? no
Version Used 0.13
FFmpeg Version ffmpeg version 3.1.3-1~bpo8+1 Copyright (c) 2000-2016 the FFmpeg developers
OS Linux

Actual Behavior

The problem happens when I try to encode into h264 and specify output width not divisible by 2 and use pad filter.

Expected Behavior

I should be able to have an output file exactly the same width as I want - 315px, not more or less.

Steps to Reproduce

$ffmpeg = FFMpeg\FFMpeg::create(FFMPEG_CONFIG_VARS);
$video = $ffmpeg->open($video_file);
$format = new FFMpeg\Format\Video\X264();

$video
    ->filters()
    ->pad(new FFMpeg\Coordinate\Dimension(315, 300)) 

$video->save($format, $final_video_file);

will produce this error [libx264 @ 0x797260] width not divisible by 2(315x170)

Possible Solutions

Some people suggest to add or remove one pixel so in my case instead of width 315px I should specify 316 or 314, but that is not accurate enough for me.

贡献者指南

技术栈
php
领域
backend
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
3
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
1-3 hours
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
stale
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
basic understanding of H.264 encoding constraintsknowledge of PHP
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
35
研究方向
Investigate the implementation of the pad filter in the PHP FFMpeg library. The issue occurs because H.264 requires width to be divisible by 2, but the library does not enforce or handle this. Look at the Pad filter class (likely in src/FFMpeg/Filters/Video/PadFilter.php) and how dimensions are passed to FFmpeg. Consider adding automatic rounding to the nearest even width for H.264 encoding, or provide a clear validation error. Refer to the issue comments for any suggested workarounds.