From 42cacd841452f7496756fe23ff219b540926172e Mon Sep 17 00:00:00 2001 From: Weaver Date: Wed, 19 Sep 2018 13:43:50 -0700 Subject: [PATCH 1/2] change to reflect aac transcode --- index.html | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/index.html b/index.html index ad8ca40..ecc75ee 100644 --- a/index.html +++ b/index.html @@ -293,7 +293,7 @@

Transcode to H.264

ffmpeg -i input_file -c:v libx264 -pix_fmt yuv420p -c:a aac output_file

-

This command takes an input file and transcodes it to H.264 with an .mp4 wrapper, keeping the audio the same codec as the original. The libx264 codec defaults to a “medium” preset for compression quality and a CRF of 23. CRF stands for constant rate factor and determines the quality and file size of the resulting H.264 video. A low CRF means high quality and large file size; a high CRF means the opposite.

+

This command takes an input file and transcodes it to H.264 with an .mp4 wrapper, audio is transcoded to AAC. The libx264 codec defaults to a “medium” preset for compression quality and a CRF of 23. CRF stands for constant rate factor and determines the quality and file size of the resulting H.264 video. A low CRF means high quality and large file size; a high CRF means the opposite.

ffmpeg
starts the command
-i input_file
path, name and extension of the input file
From e08ec96fd9b1df4b3c82a74785d24193eb3ed09e Mon Sep 17 00:00:00 2001 From: Weaver Date: Wed, 19 Sep 2018 13:57:48 -0700 Subject: [PATCH 2/2] add note for +faststart --- index.html | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/index.html b/index.html index ecc75ee..362f6c9 100644 --- a/index.html +++ b/index.html @@ -303,6 +303,11 @@ AAC is the codec most often used for audio streams within an .mp4 container.
output_file
path, name and extension of the output file
+

In order to optimize the file for streaming, you can add this preset:

+

ffmpeg -i input_file -c:v libx264 -pix_fmt yuv420p -c:a aac -movflags +faststart output_file

+
+
-movflags +faststart
This tells FFmpeg to move some of the essential metadata to the start of the file, which permits starting viewing before the file finishes downloading (an ideal characteristic for streaming).
+

In order to use the same basic command to make a higher quality file, you can add some of these presets:

ffmpeg -i input_file -c:v libx264 -pix_fmt yuv420p -preset veryslow -crf 18 -c:a aac output_file