tencent cloud

Instructions

Overview

This document describes how to transcode videos stored in VOD and how to get the outputs.

Costs

The open-source code provided here is free of charge, but the following costs may be incurred.

• Fees for purchasing a Tencent Cloud CVM instance to implement the request script of TencentCloud APIs. For more information, please see CVM Billing Plans.
• Fees for VOD storage of uploaded videos. For more information, please see Video Storage.
• Fees for VOD transcoding duration of uploaded videos. For more information, please see Video Transcoding.
• Fees for VOD traffic consumed by video playback. For more information, please see Video Acceleration.

Parameters

VOD video transcoding supports the following formats:

Parameter	Type	Description
Input format	Container format	WMV, RM, MOV, MPEG, MP4, 3GP, FLV, AVI, RMVB, TS, ASF, MPG, WebM, MKV, M3U8, WM, ASX, RAM, MPE, VOB, DAT, MP4V, M4V, F4V, MXF, QT, Ogg
	Video codec	AV1, AVS2, H.264/AVC, H.263, H.263+, H.265, MPEG-1, MPEG-2, MPEG-4, MJPEG, VP8, VP9, QuickTime, RealVideo, Windows Media Video
Output format	Container format	Video: FLV, MP4, HLS (M3U8 + TS)
		Audio: MP3, MP4, Ogg, FLAC, M4A
		Image: GIF, WebP
	Video codec	H.264/AVC, H.265/HEVC, AV1

The target specification of an output video after transcoding is specified by parameters such as codec, resolution, and bitrate. VOD integrates these parameters in the transcoding template as shown below. For details, please see Video Processing Overview.

Type	Parameter	Description
Video encoding	Codec	Supported codecs: H.264, H.265, and AV1
	Bitrate	Supported bitrate range: 10 Kbps - 35 Mbps
	Frame rate	Supported frame rate range: 1-60 fps; common values: 24, 25, 30
	Resolution	Value range of width: 128-4096 px Value range of height: 128-4096 px
	GOP length	Value range: 1-10s
	Profile	When the video codec is H.264, the Baseline, Main, and High profiles are supported. When the video codec is H.265, only the Main profile is supported.
	Color space	YUV420P is supported

Note：

• Codec: a method of converting video files from a certain format into another using specific compression technology. With advanced encoding mode for transcoding, an H.265 video has far lower bitrate than an H.264 video while the original quality is retained, which lowers the playback bandwidth usage.
• Bitrate: it refers to the size of data encoded by the encoder each second, in Kbps. For example, 800 Kbps indicates that the encoder generates 800 Kb of data per second.
• Frame rate: the number of frames that appear within a second
• Resolution: the number of pixels per inch
• GOP: the number of frames between two I-frames

Recommended bitrates, resolutions, and configuration ranges are shown below:

Clarity	Recommended Bitrate	Recommended Resolution	Resolution Range
SD	600	640 x 480	SD (Image short side ≤ 480 px)
HD	2000	1280 x 720	HD (Image short side ≤ 720 px)
FHD	4000	1920 x 1080	FHD (Image short side ≤ 1080 px)
2K	6000	2560 x 1440	2K (Image short side ≤ 1440 px)
4K	8000	3840 x 2160	4K (Image short side ≤ 2160 px)

Tencent Cloud VOD's unique TESHD is a solution integrating image quality repair and enhancement, adaptive parameter selection, and V265 encoder among other video processing features. It provides granular transcoding methods and ensures higher definition, and this solution requires low consumption of network resources while delivering better watch experience. VOD provides a wide range of preset clarity settings, with parameters detailed as follows:

Clarity	Recommended Bitrate	Recommended Resolution	Resolution Range
SD	350 or leave it empty	640 x 480	SD (Image short side ≤ 480 px)
HD	1350 or leave it empty	1280 x 720	HD (Image short side ≤ 720 px)
FHD	2700 or leave it empty	1920 x 1080	FHD (Image short side ≤ 1080 px)
2K	3500 or leave it empty	2560 x 1440	2K (Image short side ≤ 1440 px)
4K	7500 or leave it empty	3840 x 2160	4K (Image short side ≤ 2160 px)

Note：

If the bitrate is left empty, TESHD will set the minimum bitrate based on intelligent analysis of the source video.

Initiating Transcoding Through the Console

Step 1. Activate VOD

See Getting Started - Step 1. Activate VOD for details.

Step 2. Upload a video

See Getting Started - Step 2. Upload a video for details. Click here to view the test video (FileId: 3701925921390170339) for this demo.

Note：

You’re advised to use a short video (dozens of seconds) for test to avoid long transcoding duration.

Step 3. Initiate transcoding

Check the uploaded test video on the Video Management page, and then click Process Video.

In the pop-up, select Transcoding as the processing type, and then click Transcoding Template:

Select the desired transcoding template, and then click Confirm. This demo uses the system preset templates STD-H264-MP4-360P (template ID 100010) and STD-H264-MP4-540P (template ID 100020) as examples. If you need to use custom transcoding templates, please see Template Settings.

Click Confirm to initiate the transcoding.

If the status of the test video is Processing on the Video Management page, the video is being transcoded.

Step 4. View the transcoding result

When the status of the test video changes to Normal on the Video Management page, the transcoding is finished. Click Manage on the right to enter the video management page.

In the Standard Transcoding List under the Basic Info tab, videos of STD-H264-MP4-360P and STD-H264-MP4-540P specifications are the transcoding outputs. You can click Preview on the right to watch them, or click Copy address and then publish them through other channels.

Calling TencentCloud APIs to initiate transcoding

Step 1. Prepare a CVM

The TencentCloud API script needs to be executed on a CVM instance meeting the following requirements:

• Region: not limited.
• Model: the minimum official configuration (1 CPU core and 1 GB memory) is sufficient.
• Public network: a public IP is required, and the bandwidth should be at least 1 Mbps.
• Operating system: official public image Ubuntu Server 16.04.1 LTS 64-bit or Ubuntu Server 18.04.1 LTS 64-bit.

For detailed directions on how to purchase a CVM instance and reinstall the system, please see Operation Guide - Creating Instances via CVM Purchase Page and Operation Guide - Reinstalling System, respectively.

Note：

If you do not have a CVM instance satisfying the above conditions, you can also run the script on another Linux (such as CentOS or Debian) or macOS server with public network access, but you need to modify certain commands in the script based on the operating system. Please search for the specific modification method by yourself.

Step 2. Get an API key

The API key (SecretId and SecretKey) is required for calling TencentCloud APIs. If you have not created an API key yet, generate one as instructed in Root Account Access Key. If you have already created a key, get it as instructed in the same document.

Step 3. Activate VOD

See Getting Started - Step 1. Activate VOD for details.

Step 4. Upload a video

See Getting Started - Step 2. Upload a video for details. Click here to view the test video (FileId: 5285890804162014755) for this demo.

Note：

You’re advised to use a short video (dozens of seconds) for test to avoid long transcoding duration.

Step 5. Initiate transcoding

Log in to the CVM instance prepared in step 1 as instructed in Logging In to Linux Instance in Standard Login Method and enter and run the following command on the remote terminal:

ubuntu@VM-69-2-ubuntu:~$ export SECRET_ID=AKxxxxxxxxxxxxxxxxxxxxxxx; export SECRET_KEY=xxxxxxxxxxxxxxxxxxxxx;git clone https://github.com/tencentyun/vod-server-demo.git ~/vod-server-demo; bash ~/vod-server-demo/installer/transcode_api.sh

Note：

Please assign the corresponding values obtained in step 2 to SECRET_ID and SECRET_KEY in the command.

This command will download the demo source code from GitHub and automatically run the installation script. The installation process will take several minutes (subject to the CVM network conditions), during which the remote terminal will print the following information:

 [2020-06-15 20:39:56] Start installing pip3.
 [2020-06-15 20:40:06] pip3 is successfully installed.
 [2020-06-15 20:40:06] Start installing TencentCloud API Python SDK.
 [2020-06-15 20:40:07] TencentCloud API Python SDK is installed.
 [2020-06-15 20:40:07] Start configuring API parameters.
 [2020-06-15 20:40:07] API parameters are configured.

Execute the process_media.py script to initiate transcoding.

ubuntu@VM-69-2-ubuntu:~$ cd ~/vod-server-demo/transcode_api/; python3 process_media.py 5285890804162014755

Note：

Replace 5285890804162014755 in the command with the actual FileId obtained in Step 4.

This command will initiate a ProcessMedia request for the video 5285890804162014755, perform transcoding according to specifications 100010 and 100020 as defined in the VOD preset transcoding template, and print the response.

{"TaskId": "1400329073-procedurev2-f6bf6f01612369b6db30f2224792a2aft0", "RequestId": "809918fb-791c-4937-b684-5027ba6bc5f0"}

Step 6. View the transcoding result

If the status of the test video is Processing on the Video Management page, the video is being transcoded.

When the status of the test video changes to Normal, the transcoding is finished. Click Manage on the right to enter the video management page.

In the Standard Transcoding List under the Basic Info tab, videos of desired specifications are the transcoding outputs. You can click Preview on the right to watch them, or click Copy address and then publish them through other channels.

Auto Transcoding After Uploading (Task Flow)

VOD supports uploading videos through the console, from the server, from the client, and by pulling from URLs, etc. (see Media Upload for details). Each upload method supports specifying a task flow that automatically triggers transcoding after the uploading is finished.

Auto Transcoding After Uploading (Event Notification)

The VOD backend will initiate event notification requests after completing both uploading and transcoding. Developers can initiate transcoding for newly uploaded videos based on the event notifications and can also get transcoding results from such notifications (the method above is to view transcoding results from the console). For details about how to use event notifications, please see How to Receive Event Notification.