Question

摘要：无法通过服务工作人员缓存并使用缓存的音频。

尝试：使用服务工作者和缓存API缓存相对较小的音频文件（2-3mb）。它们是通过HTML Audio元素加载/播放的，它通常会设置一个＆＃39;范围＆＃39;报头中。

问题：服务工作者使用整个内容进行响应，忽略范围标头，而Audio元素忽略内容并且不播放。

没有服务工作者：服务器服从范围标题，发送部分内容，音频元素很开心并播放音频。

我正在使用Google Chrome 52。

注意：解决方案似乎已由mnot "Serve range requests from a complete cache entry"注明，但是有任何浏览器实现了这个吗？或者，有没有解决办法？

技术信息

Chrome终端stderr：[1:1:0603/164806:ERROR:render_media_log.cc(23)] MediaEvent: PIPELINE_ERROR demuxer: could not open

Chrome控制台错误：Uncaught (in promise) DOMException: The element has no supported sources.

Chrome标题（包含SW，2个部分）：

PART#1

GENERAL
Request URL:http://localhost:3333/audio.m4a
Request Method:GET
Status Code:200 OK (from ServiceWorker)
Remote Address:127.0.0.1:3333

RESPONSE
accept-ranges:bytes
connection:keep-alive
content-length:2449048
content-type:audio/x-m4a
date:Fri, 03 Jun 2016 10:14:02 GMT
etag:"56f8f953-255e98"
last-modified:Mon, 28 Mar 2016 09:28:51 GMT
server:nginx
x-content-type-options:nosniff
x-frame-options:SAMEORIGIN
x-xss-protection:1; mode=block

REQUEST
Provisional headers are shown
Accept-Encoding:identity;q=1, *;q=0
Range:bytes=0-
Referer:http://localhost:3333/
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.10 Safari/537.36

PART #2

GENERAL
Request URL:http://localhost:3333/audio.m4a
Request Method:GET
Status Code:200 OK (from ServiceWorker)
Remote Address:127.0.0.1:3333

RESPONSE
accept-ranges:bytes
connection:keep-alive
content-length:2449048
content-type:audio/x-m4a
date:Fri, 03 Jun 2016 10:14:02 GMT
etag:"56f8f953-255e98"
last-modified:Mon, 28 Mar 2016 09:28:51 GMT
server:nginx
x-content-type-options:nosniff
x-frame-options:SAMEORIGIN
x-xss-protection:1; mode=block

REQUEST
Provisional headers are shown
Accept-Encoding:identity;q=1, *;q=0
Range:bytes=2392064-
Referer:http://localhost:3333/
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.10 Safari/537.36

Chrome标头（不含SW，3个部分！）：

PART #1

GENERAL
Request URL:http://localhost:3333/audio.m4a
Request Method:GET
Status Code:206 Partial Content
Remote Address:127.0.0.1:3333

RESPONSE
Connection:keep-alive
Content-Length:2449048
Content-Range:bytes 0-2449047/2449048
Content-Type:audio/x-m4a
Date:Fri, 03 Jun 2016 10:24:32 GMT
ETag:"56f8f953-255e98"
Last-Modified:Mon, 28 Mar 2016 09:28:51 GMT
Server:nginx
X-Content-Type-Options:nosniff
X-Frame-Options:SAMEORIGIN
X-XSS-Protection:1; mode=block

REQUEST
Accept:*/*
Accept-Encoding:identity;q=1, *;q=0
Accept-Language:en-GB,en-US;q=0.8,en;q=0.6
Connection:keep-alive
Host:localhost:3333
Range:bytes=0-
Referer:http://localhost:3333/
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.10 Safari/537.36

PART #2

GENERAL
Request URL:http://localhost:3333/audio.m4a
Request Method:GET
Status Code:206 Partial Content
Remote Address:127.0.0.1:3333

RESPONSE
Connection:keep-alive
Content-Length:56984
Content-Range:bytes 2392064-2449047/2449048
Content-Type:audio/x-m4a
Date:Fri, 03 Jun 2016 10:24:32 GMT
ETag:"56f8f953-255e98"
Last-Modified:Mon, 28 Mar 2016 09:28:51 GMT
Server:nginx
X-Content-Type-Options:nosniff
X-Frame-Options:SAMEORIGIN
X-XSS-Protection:1; mode=block

REQUEST
Accept:*/*
Accept-Encoding:identity;q=1, *;q=0
Accept-Language:en-GB,en-US;q=0.8,en;q=0.6
Connection:keep-alive
Host:localhost:3333
If-Range:"56f8f953-255e98"
Range:bytes=2392064-2449047
Referer:http://localhost:3333/
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.10 Safari/537.36


PART #3

GENERAL
Request URL:http://localhost:3333/audio.m4a
Request Method:GET
Status Code:206 Partial Content
Remote Address:127.0.0.1:3333

RESPONSE
Content-Length:2121368
Content-Range:bytes 327680-2449047/2449048
Content-Type:audio/x-m4a
Date:Fri, 03 Jun 2016 10:24:32 GMT
ETag:"56f8f953-255e98"
Last-Modified:Mon, 28 Mar 2016 09:28:51 GMT
Server:nginx
X-Content-Type-Options:nosniff
X-Frame-Options:SAMEORIGIN
X-XSS-Protection:1; mode=block

REQUEST
Provisional headers are shown
Accept-Encoding:identity;q=1, *;q=0
Range:bytes=327680-
Referer:http://localhost:3333/
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.10 Safari/537.36

Answer 1

通过手动创建的远程响应，查看解决此问题的https://samdutton.github.io/samples/service-worker/prefetch-video/。

修复此问题是为了确定浏览器应该在这里做什么，并在需要时更新服务工作者规范。

Answer 2

我使用IndexedDB实现了此功能，结果令人印象深刻。您可以使用localForage将音频文件存储在数据库中，然后通过blob src url以离线模式检索它。

request = new XMLHttpRequest();
request.open('GET', audioURL, true);
request.responseType = 'blob';
request.onreadystatechange = function(){
if (request.readyState === 4 && request.status === 200){
    localforage.setItem('KeyName', request.response).then(function(savedAudioBlob) { console.log('Saved Blob URL ' + savedAudioBlob); }); }

无法从服务工作者播放缓存的音频

2 个答案: