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Android 和 IOS 上加载什么 h.264 格式？

发布于 2024-11-15 18:27:03 字数 162 浏览 4 评论 0原文

理论上，IOS 和 ANDROID 都可以播放 h.264 文件，但我无法找到对它们进行编码的设置，以便它们实际上可以跨平台工作。有人知道如何使用一个文件同时为 Android 和 IOS 进行编码吗？

ps 我了解 html5 视频和后备源的所有信息，我只是不想为每个设备编码和托管新视频。

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野心澎湃 2024-11-22 18:27:03

这是我们在生产环境中用于转码为 MPEG-4 h.264 的 ffmpeg 命令行。我们已经在多种 Android 设备以及 iOS 设备上测试了输出。您可以使用它作为起点，只需调整帧大小/帧速率和 qfactor 等内容。

ffmpeg -y 
-i #{input_file} 
-s 432x320 
-b 384k 
-vcodec libx264 
-flags +loop+mv4 
-cmp 256 
-partitions +parti4x4+parti8x8+partp4x4+partp8x8 
-subq 6 
-trellis 0 
-refs 5 
-bf 0 
-flags2 +mixed_refs 
-coder 0 
-me_range 16 
-g 250 
-keyint_min 25 
-sc_threshold 40 
-i_qfactor 0.71 
-qmin 10 -qmax 51 
-qdiff 4 
-acodec libfaac 
-ac 1 
-ar 16000 
-r 13 
-ab 32000 
-aspect 3:2 
#{output_file}

影响 Android 兼容性的一些重要选项包括：

-coder 0      Uses CAVLAC rather than CABAC entropy encoding (CABAC not supported on Android)
-trellis 0    Should be shut off, requires CABAC
-bf 0         Turns off B-frames, not supported on Android or other h.264 Baseline Profile devices
-subq 6       Determines what algorithms are used for subpixel motion searching. 7 applies to B-frames, not supported on Android.
-refs 5       Determines how many frames are referenced prior to the current frame.  Increasing this number could affect compatibility

使用此 ffmpeg 配方对视频进行编码后，我们还通过 qt- 传递视频快速启动。此步骤将重新分块视频以进行流式传输。我们通过 HTTP 将其流式传输到 Android 应用程序中的嵌入式 VideoView。流式传输到我们所知的任何 Android 设备都没有问题。

2013-06-17 更新：我只是想添加一条注释，即最好坚持使用 H.264 编码的“基线”配置文件，以便在所有 Android 设备上实现最大兼容性。上面的命令行没有明确指定 H.264 配置文件，但 ffmpeg 确实有一个 -profile 如果您使用其预设，则命令行标志非常有用。您可能不应该弄乱 -profile。我使用“main”而不是“baseline”配置文件（通过 Handbrake）为我的 ASUS Transformer 300 平板电脑（Android 4.2）编码视频。 “主要”配置文件出现了播放时音频与视频不同步的问题。

Here's the ffmpeg command line we use to transcode to MPEG-4 h.264 in our production environment. We've tested the output on several Android devices, as well as iOS. You can use this as a starting point, just tweaking things like frame size/frame rate and qfactor.

ffmpeg -y 
-i #{input_file} 
-s 432x320 
-b 384k 
-vcodec libx264 
-flags +loop+mv4 
-cmp 256 
-partitions +parti4x4+parti8x8+partp4x4+partp8x8 
-subq 6 
-trellis 0 
-refs 5 
-bf 0 
-flags2 +mixed_refs 
-coder 0 
-me_range 16 
-g 250 
-keyint_min 25 
-sc_threshold 40 
-i_qfactor 0.71 
-qmin 10 -qmax 51 
-qdiff 4 
-acodec libfaac 
-ac 1 
-ar 16000 
-r 13 
-ab 32000 
-aspect 3:2 
#{output_file}

Some of the important options affecting Android compatibility are:

-coder 0      Uses CAVLAC rather than CABAC entropy encoding (CABAC not supported on Android)
-trellis 0    Should be shut off, requires CABAC
-bf 0         Turns off B-frames, not supported on Android or other h.264 Baseline Profile devices
-subq 6       Determines what algorithms are used for subpixel motion searching. 7 applies to B-frames, not supported on Android.
-refs 5       Determines how many frames are referenced prior to the current frame.  Increasing this number could affect compatibility

After we encode our video with this ffmpeg recipe, we also pass the video through qt-faststart. This step rechunks the video for streaming. We stream it over HTTP to an embedded VideoView within our Android app. No problems streaming to any Android device we're aware of.

Update 2013-06-17: I just wanted to add a note that it's best to stick with "baseline" profile for H.264 encoding for maximum compatibility across all Android devices. The above command line doesn't explicitly specify an H.264 profile, but ffmpeg does have a -profile command line flag that is useful if you are using its presets. You probably shouldn't mess with -profile. I have encoded videos for my ASUS Transformer 300 tablet (Android 4.2) using "main" rather than "baseline" profile (via Handbrake). The "main" profile gave problems with audio getting out of sync with video on playback.

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我一直都在从未离去 2024-11-22 18:27:03

我用它制作了一个带有嵌入式视频的 Android 和 iOS 应用程序。视频在两个版本中均播放。（Android 示例）（iOS示例)

补充答案

此答案是对解释某些参数的已接受答案的补充。

ffmpeg 
-y                  # Overwrite output files without asking.
-i input_filename   # input file name    
-s 432x320          # size of output file
-b:v 384k           # bitrate for video
-vcodec libx264     # use H.264 video codec
-flags +loop+mv4    # use loop filter and four motion vector by macroblock
-cmp 256            # ??? Full pel motion estimation compare function
-partitions +parti4x4+parti8x8+partp4x4+partp8x8      #???
-subq 6             # determines algorythms for subpixel motion searching and partition decision
-trellis 0          # optimal rounding choices
-refs 5             # number of frames referenced prior to current frame
-bf 0               # turn of B-frames, something to do with H.264 and Baseline Profile
-flags2 +mixed_refs # ??? gave me an error so I just deleted it
-coder 0            # turn of the CABAC entropy encoder
-me_range 16        # max range of the motion search
-g 250              # GOP length (250 is the recommended default)
-keyint_min 25      # Minimum GOP length (25 is the recommended default)
-sc_threshold 40    # adjusts sensitivity of x264's scenecut detection (default is 40) 
-i_qfactor 0.71     # Qscale difference between I-frames and P-frames (0.71 is the recommended default)
-qmin 10 -qmax 51   # min and max quantizer (10 and 51 are the recommended defaults)
-qdiff 4            # max QP step (4 is recommended default)
-c:a aac            # Set the audio codec to use AAC
-ac 1               # number of audio channels 
-ar 16000           # audio sampling frequency
-r 13               # frames per second
-ab 32000           # audio bitrate
-aspect 3:2         # sample aspect ratio
output_filename     # name of the output file

如果您可以填写一些我不确定的详细信息，请随时编辑此内容。

这里再次采用剪切粘贴格式。（我还必须添加 -strict -2 参数才能使 aac 在我的计算机上工作。）

ffmpeg -y -i input_file.avi -s 432x320 -b:v 384k -vcodec libx264 -flags +loop+mv4 -cmp 256 -partitions +parti4x4+parti8x8+partp4x4+partp8x8 -subq 6 -trellis 0 -refs 5 -bf 0 -coder 0 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -qmin 10 -qmax 51 -qdiff 4 -c:a aac -ac 1 -ar 16000 -r 13 -ab 32000 -aspect 3:2 -strict -2 output_file.mp4

进一步研究

我在以下链接中找到了大部分信息：

< a href="http://www.ffmpeg.org/ffmpeg-all.html#Description" rel="nofollow noreferrer">ffmpeg 文档
x264 FFmpeg 选项指南
FFMPEG 中级指南/Flags 标志

另请参阅

Android VideoView 示例

I used this to make an Android and iOS app with embedded videos. The videos played in both versions. (Android example) (iOS example)

Supplemental answer

This answer is a supplement to the accepted answer explaining some of the parameters.

ffmpeg 
-y                  # Overwrite output files without asking.
-i input_filename   # input file name    
-s 432x320          # size of output file
-b:v 384k           # bitrate for video
-vcodec libx264     # use H.264 video codec
-flags +loop+mv4    # use loop filter and four motion vector by macroblock
-cmp 256            # ??? Full pel motion estimation compare function
-partitions +parti4x4+parti8x8+partp4x4+partp8x8      #???
-subq 6             # determines algorythms for subpixel motion searching and partition decision
-trellis 0          # optimal rounding choices
-refs 5             # number of frames referenced prior to current frame
-bf 0               # turn of B-frames, something to do with H.264 and Baseline Profile
-flags2 +mixed_refs # ??? gave me an error so I just deleted it
-coder 0            # turn of the CABAC entropy encoder
-me_range 16        # max range of the motion search
-g 250              # GOP length (250 is the recommended default)
-keyint_min 25      # Minimum GOP length (25 is the recommended default)
-sc_threshold 40    # adjusts sensitivity of x264's scenecut detection (default is 40) 
-i_qfactor 0.71     # Qscale difference between I-frames and P-frames (0.71 is the recommended default)
-qmin 10 -qmax 51   # min and max quantizer (10 and 51 are the recommended defaults)
-qdiff 4            # max QP step (4 is recommended default)
-c:a aac            # Set the audio codec to use AAC
-ac 1               # number of audio channels 
-ar 16000           # audio sampling frequency
-r 13               # frames per second
-ab 32000           # audio bitrate
-aspect 3:2         # sample aspect ratio
output_filename     # name of the output file

Feel free to edit this if you can fill in some of the details I wasn't sure about.

Here it is again in a cut-and-paste format. (I also had to add the -strict -2 parameter to get aac to work on my computer.)

ffmpeg -y -i input_file.avi -s 432x320 -b:v 384k -vcodec libx264 -flags +loop+mv4 -cmp 256 -partitions +parti4x4+parti8x8+partp4x4+partp8x8 -subq 6 -trellis 0 -refs 5 -bf 0 -coder 0 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -qmin 10 -qmax 51 -qdiff 4 -c:a aac -ac 1 -ar 16000 -r 13 -ab 32000 -aspect 3:2 -strict -2 output_file.mp4

Further Study

Most of this information I found at the following links:

Android 和 IOS 上加载什么 h.264 格式？

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

评论（3）

补充答案

进一步研究

另请参阅

Supplemental answer

Further Study

See also

关于作者

相关话题

热门标签

推荐作者

胡图图

zt006

z祗昰~

冰葑

野の

天空

友情链接

Android 和 IOS 上加载什么 h.264 格式？

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

评论（3）

补充答案

进一步研究

另请参阅

Supplemental answer

Further Study

See also

关于作者

相关话题

热门标签

推荐作者

胡图图

zt006

z祗昰~

冰葑

野の

天空

友情链接

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。