ABC iview is a video on demand service from the Australian Broadcasting Corporation. In 2015, we built a new service in-house to handle transcoding for all of iview's content. Metro is built on AWS, and uses FFmpeg, node.js and go components to transcode content quickly and cost-efficiently. This talk was presented on August 4th 2016 at NDC Sydney.

1. Video Transcoding
at Scale for ABC iview
Daphne Chong
@daphnechong

5. metro

6. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

7. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

9. What changes
are we making?

12. High speed
Medium speed
Low speed

13. Standard
Encoding
H.264 MP4

14. Transcoding
Example

15. Step 1: Prepare watermark

16. Step 1: Prepare watermark

17. Step 1: Prepare watermark

18. Step 2: Input video (GXF)

19. Step 3: Asymmetrical cropping

20. Step 4: Scale and set aspect ratio

21. Step 5: Apply watermark

22. Step 6: Ready to stream
1500k

23. other rendition sizes
1000k
650k
500k
220k
audio only

24. Original file audio track

25. Previous transcoder audio track

26. After audio normalisation

27. That’s a lot of
changes...

28. Transcoding
Profiles

29. GXF, ABC1
Profile:
- Renditions (6)
- Crop
- Normalise audio
- Adjust ratio
- Add watermark
- GXF to MP4

30. GXF, ABC1

31. GXF, ABC1
MOV, Arts
Profile:
- Renditions (6)
- Adjust ratio
- ProRes MOV to MP4

32. GXF, ABC1
MOV, Arts

33. What is this
“Magic Video Software”
you speak of?

35. ./ffmpeg -i utopia.gxf utopia.mp4

36. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

37. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

38. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

39. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

40. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

41. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

42. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

43. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

44. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

45. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

46. ./ffmpeg -i INPUT -c:v libx264 -filter_complex
"[0:v]crop=720:576:0:32,yadif,scale=1024x576,setdar=16/9[ma
in], [1:v]scale=54:-1[ovrl],
[main][ovrl]overlay=main_w-overlay_w-47:main_h-overlay_h-44
" -crf 22 -maxrate 1404k -bufsize 1500k -pix_fmt yuv420p
-profile:v high -level 4.0 -refs 3 -r 25 -g 50 -c:a
libfdk_aac -b:a 96k -filter_complex "[0:a:0][0:a:1]
amerge=inputs=2,
dynaudnorm=f=500:g=31:p=0.82:m=30.0:r=0.0:s=0.0 [aout]" -ar
44100 -ac 2 -map 0:0 -map "[aout]" -movflags +faststart
-threads 0 -y OUTPUT
In reality, it looks like this

48. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

49. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

50. Cost
Scale
Flexibility

51. Cost
Scale
Flexibility

54. thesupercarkids.com

55. mini-me.com

56. Cost
Scale
Flexibility

58. “The Cloud”

59. Cost
Scale
Flexibility

61. Cost
Scale
Flexibility

62. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

63. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

64. Source
Queue
Process
Transfer
Notify

80. 8 minutes 27 seconds

81. Original
length
Time to produce rendition
60 min
7 min
42 min
Lowest
(audio)
Highest
(1500k)

83. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

84. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

85. Languages:
Node.js
Go

88. Node.js
Existing team experience
Rapid development for APIs
Untyped. Sadface.

90. Go
Typed and compiled
Cross-platform
Easy deployment
Learning curve

91. Infrastructure:
EC2, SQS, S3, SNS,
Dynamo / RDS,
Cloudformation

92. AWS - EC2
Autoscaling

95. AWS - SQS
Simple Queuing
System

97. SQS
First in first out (FIFO)
Single consumer per message
Message has “visibility timeout”
Adjustable visibility timeout

98. AWS - S3
File Storage

100. AWS - DynamoDB

101. AWS - DynamoDB

102. AWS - DynamoDB
AWS - MySQL on RDS

104. DynamoDB
NoSQL
Key-value pair storage
Pay for number of records/sec read

105. DynamoDB
Our use case was not optimal
Manual aggregations
Higher cost than expected
Doesn’t scale automatically

106. MySQL
Switched to MySQL on RDS
Managed hosting
Aggregations!
Data structure ported as-is

107. AWS Cloudformation

109. "ExampleLoadBalancer" : {
"Type" : "AWS::ElasticLoadBalancing::LoadBalancer",
"Properties" : {
"AvailabilityZones" : [ "us-east-1a", "us-east-1b" ],
"Listeners" : [ {
"LoadBalancerPort" : "80",
"InstancePort" : "8081",
"Protocol" : "HTTP"
} ]
}
}

111. Node.js + Go
AWS Infrastructure

112. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

113. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

115. When should
you scale?

116. Scaling Considerations
Hourly billing
Instance size: Cost vs Speed
Content priority
Ad-hoc requests
Varied content length

117. Scaling Considerations:
AWS limitations
AWS scaling metrics can be slow
No automatic off switch
Can’t choose instances to scale down
(Instance protection now available)

119. MVP:
Don’t make things wait
too long

120. MVP:
Supply enough
capacity at all times

121. MVP:
Driven by drop folders

122. GXF, ABC1
Profile:
- Renditions (2)
- Crop
- Normalise audio
- Adjust ratio
- Add watermark
- GXF to MP4

128. var autoscaling = new AWS.AutoScaling(...);
var params = {
AutoScalingGroupName: groupName,
DesiredCapacity: capacity
Some white text
};
autoscaling.setDesiredCapacity(params, ...);

129. var autoscaling = new AWS.AutoScaling(...);
var params = {
AutoScalingGroupName: groupName,
DesiredCapacity: capacity
Some white text
};
autoscaling.setDesiredCapacity(params, ...);

130. Amazon Machine
Images (AMIs)

131. Which instance size?

132. Time vs Cost
for 1 hour of content
Time Cost
?

133. Winner:
c4.xlarge

134. Up: step scaling
Down: stop everything

140. An interesting puzzle :)

141. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

142. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

143. 24 hours in
Transcoding

144. (10am - 10am)

145. $57.22

146. $42.86
US Dollars

147. EC2 Instances: $34.31
EC2 (other): $ 4.24
RDS: $ 2.66
S3: $ 1.65
SQS: $ 0.00
Total (USD): $42.86
Transcoding costs: 24 hrs

148. Next 24 hours
Approx 70% of the volume

149. $34.63
Australian Dollars

150. One year’s costs?

151. $16.5k
Australian Dollars

152. $12.5k
US Dollars

153. This is a BIG deal!

154. thesupercarkids.com

155. bikesandbeyond.ca

156. 8 minutes 27 seconds

158. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

159. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

160. AWS & throughput
optimisations

163. Transcoding in
chunks/segments

165. Introspection &
Validation

166. GXF, ABC1
Profile:
- Crop
- Normalise audio
- Adjust ratio
- Add watermark
- GXF to MP4

167. ffprobe

171. 1. What is Transcoding?
2. Why build our own system?
3. Architecture
4. Technology choices
5. Autoscaling transcoders
6. Costs
7. Future roadmap

172. Summary

177. 8 minutes 27 seconds

179. @daphnechong
Thanks!

180. Q&A