一、效果
功能需求：获取StreamingAssets文件夹下的所有视频（包含其子文件夹），获取指定时间的视频画面，然后将图片保存到本地磁盘中。
二、关于Avpro的事件监听
当指定视频时间进度时会触发FinishedSeeking，代表加载完成这时我们在进行缩略图创建功能，否则视频帧未更新创建缩略图会出现问题。
//使用方法
mediaPlayer.Events.AddListener(OnVideoEvent);
//监听
private void OnVideoEvent(MediaPlayer mp, MediaPlayerEvent.EventType et, ErrorCode errorCode)
{
switch (et)
{
case MediaPlayerEvent.EventType.MetaDataReady:
Debug.Log("当元数据(宽度，持续时间等)可用时触发");
break;
case MediaPlayerEvent.EventType.ReadyToPlay:
Debug.Log("可以播放");
break;
case MediaPlayerEvent.EventType.Started:
Debug.Log("播放开始时触发");
break;
case MediaPlayerEvent.EventType.FirstFrameReady:
Debug.Log("第一帧渲染完成");
break;
case MediaPlayerEvent.EventType.FinishedPlaying:
Debug.Log("视频结束");
break;
case MediaPlayerEvent.EventType.Closing:
Debug.Log("媒体关闭时触发");
break;
case MediaPlayerEvent.EventType.Error:
Debug.Log("发生错误时触发");
break;
case MediaPlayerEvent.EventType.SubtitleChange:
Debug.Log("字幕改变时触发");
break;
case MediaPlayerEvent.EventType.Stalled:
Debug.Log("当介质停止时触发(例如。当失去与媒体流的连接时)");
break;
case MediaPlayerEvent.EventType.Unstalled:
Debug.Log("当媒体从停止状态恢复时触发(例如。当失去的连接重新建立时)");
break;
case MediaPlayerEvent.EventType.ResolutionChanged:
Debug.Log("当视频的分辨率发生变化(包括加载)时触发，用于自适应流");
break;
case MediaPlayerEvent.EventType.StartedSeeking:
Debug.Log("搜索开始时触发");
break;
case MediaPlayerEvent.EventType.FinishedSeeking:
Debug.Log("搜索完成时触发 Seek视频指定时间跳转结束后调用");
break;
case MediaPlayerEvent.EventType.StartedBuffering:
Debug.Log("缓冲开始时触发");
break;
case MediaPlayerEvent.EventType.FinishedBuffering:
Debug.Log("缓冲完成时触发");
break;
case MediaPlayerEvent.EventType.PropertiesChanged:
Debug.Log("当任何属性被触发(例如立体声包装被改变)-这必须手动触发");
break;
case MediaPlayerEvent.EventType.PlaylistItemChanged:
Debug.Log("当新项目在播放列表中播放时触发");
break;
case MediaPlayerEvent.EventType.PlaylistFinished:
Debug.Log("当播放列表结束时触发");
break;
case MediaPlayerEvent.EventType.TextTracksChanged:
Debug.Log("当添加或删除文本轨道时触发");
break;
}
}三、脚本
下面我使用了两种方式创建缩略图
using System.IO;
using UnityEngine;
using RenderHeads.Media.AVProVideo;
using System.Collections.Generic;
using System.Collections;
public class ThumbnailGenerator : MonoBehaviour
{
public MediaPlayer mediaPlayer;
public float thumbnailTime = 1.0f; //时间戳，用于生成缩略图的位置
int index;//当前视频地址
List<string> filesPath = new List<string>();
void Start()
{
string[] videoFiles = Directory.GetFiles(Application.streamingAssetsPath, "*.*", SearchOption.AllDirectories);
foreach (string videoFile in videoFiles)
{
string extension = Path.GetExtension(videoFile).ToLower();
if (extension == ".mp4" || extension == ".avi" || extension == ".mov") // 检查支持的视频格式
filesPath.Add(videoFile);//添加所有视频地址
}
//方法一 协程创建
//StartCoroutine(SeekAndWaitForLoad(mediaPlayer, thumbnailTime, filesPath[0]));
//方法二 视频状态监听 创建
mediaPlayer.Events.AddListener(OnVideoEvent);
mediaPlayer.OpenMedia(MediaPathType.AbsolutePathOrURL, filesPath[0], false);
mediaPlayer.Control.Seek(thumbnailTime);// 执行Seek操作
}
#region 方法一 使用协程创建
/// <summary>
/// 创建视频缩略图
/// </summary>
/// <param name="mp">视频播放器</param>
/// <param name="time">视频指定时间</param>
/// <param name="path">视频地址</param>
/// <returns></returns>
private IEnumerator SeekAndWaitForLoad(MediaPlayer mp, float time, string path)
{
mp.OpenMedia(MediaPathType.AbsolutePathOrURL, path, false);
// 执行Seek操作
mp.Control.Seek(time);
// 等待寻址完成
yield return new WaitUntil(() => !mp.Control.IsSeeking());
// 确保播放时间已经跳转到期望的时间点
yield return new WaitUntil(() => Mathf.Abs((float)mp.Control.GetCurrentTime() - time) < 0.1f);
// 可选：等待视频帧更新完成 (确保画面已经渲染)
yield return new WaitForEndOfFrame();
Debug.Log("寻找完整的和视频帧加载时间: " + mp.Control.GetCurrentTime());
//获取视频 RenderTexture
RenderTexture renderTexture = GetVideoRenderTexture(mp);
//将RenderTexture转换成texture2D
Texture2D texture2D = RenderTexture2Texture2D(renderTexture);
//将Texture2D写入本地
string previewPath = Path.Combine(Path.GetDirectoryName(path), Path.GetFileNameWithoutExtension(path)) + ".png";
Texture2dWriteLocal(texture2D, previewPath);
//创建下一个缩略图
index++;
if (index < filesPath.Count)
StartCoroutine(SeekAndWaitForLoad(mediaPlayer, thumbnailTime, filesPath[0]));
}
#endregion
#region 方法二 视频状态监听
private void OnVideoEvent(MediaPlayer mp, MediaPlayerEvent.EventType et, ErrorCode errorCode)
{
string path = mp.MediaPath.Path;
switch (et)
{
case MediaPlayerEvent.EventType.FinishedSeeking:
Debug.Log("搜索完成时触发");
//获取视频 RenderTexture
RenderTexture renderTexture = GetVideoRenderTexture(mp);
//将RenderTexture转换成texture2D
Texture2D texture2D = RenderTexture2Texture2D(renderTexture);
//将Texture2D写入本地
string previewPath = Path.Combine(Path.GetDirectoryName(path), Path.GetFileNameWithoutExtension(path)) + ".png";
Texture2dWriteLocal(texture2D, previewPath);
//创建下一个缩略图
index++;
if (index < filesPath.Count)
{
mp.OpenMedia(MediaPathType.AbsolutePathOrURL, filesPath[index], false);
mp.Control.Seek(thumbnailTime);// 执行Seek操作
}
break;
}
}
#endregion
#region 获取视频 RenderTexture
Material mt;
RenderTexture GetVideoRenderTexture(MediaPlayer mp)
{
if (mt == null)
{
mt = new Material(Shader.Find("AVProVideo/Internal/Resolve"));
mt.color = Color.white;//颜色设置
mt.DisableKeyword("USE_HSBC");//禁用USE_HSBC关键字
}
VideoRender.SetupMaterialForMedia(mt, mp, -1); //设置材质贴图等
VideoRender.ResolveFlags resolveFlags = (VideoRender.ResolveFlags.ColorspaceSRGB | VideoRender.ResolveFlags.Mipmaps | VideoRender.ResolveFlags.PackedAlpha | VideoRender.ResolveFlags.StereoLeft);//播放器标志
return VideoRender.ResolveVideoToRenderTexture(mt, null, mp.TextureProducer, resolveFlags);//将视频解析为RenderTexture
}
#endregion
#region 将RenderTexture转换为Texture2D
private static Texture2D RenderTexture2Texture2D(RenderTexture renderTexture)
{
int width = renderTexture.width;
int height = renderTexture.height;
Texture2D texture2D = new Texture2D(width, height, TextureFormat.ARGB32, false);
RenderTexture.active = renderTexture;
texture2D.ReadPixels(new Rect(0, 0, width, height), 0, 0);
texture2D.wrapMode = TextureWrapMode.Clamp;
texture2D.Apply();
return texture2D;
}
#endregion
#region 将Texture2d写入本地
void Texture2dWriteLocal(Texture2D texture2D, string localPath)
{
File.WriteAllBytes(localPath, texture2D.EncodeToPNG());
}
#endregion
}
在使用avpro制作缩略图时，我尝试使用mediaPlayer.TextureProducer.GetTexture()；方法获取画面Texture,然后将其写入RenderTexture，在转换Texture2D写入本地会发现缩略图颜色泛白，经过排查MediaPlayer原脚本，发现在转换RenderTexture时需要使用avpro的指定shader处理才会显示正确的材质，感兴趣的朋友可以打开MediaPlayer脚本进行查看
原脚本查看方法：
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