hls aes加密视频在ios上的EXT-X-DISCONTINUITY标签后不播放

Question

看起来 ios 不喜欢将加密的 .ts 文件与 EXT-X-DISCONTINUITY 标签混合的 hls m3u8 文件。

这是一个测试播放列表，它是两个视频的混合。未加密的前置广告和主要加密视频。两者分开播放都很好，但是当我将它们放在一个 m3u8 中，由 EXT-X-DISCONTINUITY 分隔时，只播放前卷，然后播放器停止。

#EXTM3U
#EXT-X-TARGETDURATION:10
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/vig_400-0.ts
#EXTINF:10,
http://ixemes-ppweb.ixemes.com/prerollmain/vig_400-1.ts
#EXT-X-DISCONTINUITY
#EXTINF:10,
#EXT-X-KEY:METHOD=AES-128,URI="http://ixemes-ppweb.ixemes.com/prerollmain/113760.key"
http://ixemes-ppweb.ixemes.com/prerollmain/02-0.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-1.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-2.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-3.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-4.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-5.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-6.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-7.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-8.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-9.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-10.ts
#EXTINF:10,     
http://ixemes-ppweb.ixemes.com/prerollmain/02-11.ts
#EXTINF:2,      
http://ixemes-ppweb.ixemes.com/prerollmain/02-12.ts
#EXT-X-ENDLIST

我尝试了两个未加密的视频，它可以工作。而且我在 HLS 规范中没有看到任何内容表明禁止在加密视频中使用 EXT-X-DISCONTINUITY 标签：https://datatracker.ietf.org/doc/html/draft-pantos-http-live-streaming-08#section-6.3.3

所以我猜是苹果对其自身规范的实现是错误的，但也许是我做错了。

我已经制作了一个快速的 html 页面来测试它（在任何 ios5 设备上的 safari 中打开它）：http://ixemes-ppweb.ixemes.com/prerollmain/index.html

Answer 1

我注意到您的 EXT-X-KEY 没有 IV 项，即初始化向量。这是标准支持的，例如：

#EXT-X-KEY:METHOD=AES-128,URI="https://priv.example.com/key.php?r=52",IV=0x9c7db8778570d05c3177c349fd9236aa

如果缺少这个，https://developer.apple.com/library/ios/technotes/tn2288/_index.html 告诉玩家应该选择 IV：

媒体加密的默认初始化向量（如果没有 指定）是媒体文件的序列号。你应该 指定一个初始化向量值，而不依赖于序列 数字。主要原因是便携性。例如，如果您 更改片段在播放列表中的显示位置（例如，插入 ad)，这会改变其序列号，需要重新加密。

在我的团队中，我们无法弄清楚为什么带有插入广告的加密内容无法播放。我们有一个播放的加密内容示例：

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:1
#EXT-X-ALLOW-CACHE:NO
#EXT-X-TARGETDURATION:11
#EXT-X-KEY:METHOD=AES-128,URI="http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans.key"
#EXTINF:11,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-1.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-2.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-3.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-4.ts
#EXTINF:10,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-5.ts
#EXTINF:6,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-6.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-7.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-8.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-9.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-10.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-11.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-12.ts
#EXTINF:6,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-13.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-14.ts
#EXTINF:5,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-15.ts
#EXT-X-ENDLIST

您可以在http://demo.theplatform.com/dev/m3u8/encrypted.m3u8 试试这个。但是当我们在它之前插入内容时，就像这样，它没有播放：

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:1
#EXT-X-ALLOW-CACHE:NO
#EXT-X-TARGETDURATION:11
#EXT-X-KEY:METHOD=NONE
#EXTINF:10.01,
http://ne.edgecastcdn.net/0008B0/mps/Inkola_VMS/20/687/15_WordIsOut_UPFW1764H_1080p_20802040_m3u8_video_480x0_400000_primary_audio_eng_2_x5e1c9dd7b9834f38a319d348e1a5f9ee_00001.ts
#EXTINF:5.088,
http://ne.edgecastcdn.net/0008B0/mps/Inkola_VMS/20/687/15_WordIsOut_UPFW1764H_1080p_20802040_m3u8_video_480x0_400000_primary_audio_eng_2_x5e1c9dd7b9834f38a319d348e1a5f9ee_00002.ts
#EXT-X-DISCONTINUITY
#EXT-X-KEY:METHOD=AES-128,URI="http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans.key"
#EXTINF:11,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-1.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-2.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-3.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-4.ts
#EXTINF:10,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-5.ts
#EXTINF:6,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-6.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-7.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-8.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-9.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-10.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-11.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-12.ts
#EXTINF:6,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-13.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-14.ts
#EXTINF:5,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-15.ts
#EXT-X-ENDLIST

这个网址是http://demo.theplatform.com/dev/m3u8/mix.m3u8。我们发现问题是因为我们添加了两个片段，媒体序列号现在偏离了 2。如果您将 IV 显式设置为“0x000000000000000000000000000000001”，如下所示：

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:1
#EXT-X-ALLOW-CACHE:NO
#EXT-X-TARGETDURATION:11
#EXT-X-KEY:METHOD=NONE
#EXTINF:10.01,
http://ne.edgecastcdn.net/0008B0/mps/Inkola_VMS/20/687/15_WordIsOut_UPFW1764H_1080p_20802040_m3u8_video_480x0_400000_primary_audio_eng_2_x5e1c9dd7b9834f38a319d348e1a5f9ee_00001.ts
#EXTINF:5.088,
http://ne.edgecastcdn.net/0008B0/mps/Inkola_VMS/20/687/15_WordIsOut_UPFW1764H_1080p_20802040_m3u8_video_480x0_400000_primary_audio_eng_2_x5e1c9dd7b9834f38a319d348e1a5f9ee_00002.ts
#EXT-X-DISCONTINUITY
#EXT-X-KEY:METHOD=AES-128,URI="http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans.key",IV=0x00000000000000000000000000000001
#EXTINF:11,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-1.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-2.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-3.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-4.ts
#EXTINF:10,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-5.ts
#EXTINF:6,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-6.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-7.ts
#EXTINF:7,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-8.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-9.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-10.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-11.ts
#EXTINF:8,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-12.ts
#EXTINF:6,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-13.ts
#EXTINF:9,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-14.ts
#EXTINF:5,
http://playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes-audio=65000-video=2042000-15.ts
#EXT-X-ENDLIST

然后就可以了。你可以试试http://demo.theplatform.com/dev/m3u8/mix_fixed.m3u8。所以也许这就是你遇到的问题。

Answer 2

好吧，它看起来与主视频的加密无关，而是与主视频的编码方式有关。我无法控制主视频的编码方式。我只对自己的预卷视频进行编码（并分块）用于测试目的。

如果我将前卷与相同的主视频混合但未加密，它也不起作用。 如果我混合由同一个外部编码器编码的两个视频，加密（或不加密）它不起作用。 不知道外部编码器的then编码参数有什么问题，但是不连续标签不起作用。

但是，如果我自己编码两个视频（前卷和主视频），加密主视频，然后使用不连续性标签将它们放入单个 m3u8 文件中，它就可以工作。

所以ios处理不连续标签的方式还是有问题，没有完全重置播放器参数，但至少可以在加密前插入未加密的前卷视频。