Different download tools result in different MP3 checksums [closed]
I wrote some code for downloading podcasts and noticed that the checksums of files I downloaded with it didn't match those of files downloaded using other methods.
Initially I thought there was a bug in my code but through testing I've noticed that files downloaded using wget, curl and Invoke-WebRequest also differ from each other. I've tested on my Windows 10 PC and an Ubuntu 16.04 VPS I have and the same thing happens on both.
Does anybody have any idea what might be causing this?
http wget mp3 curl checksum
asked Dec 15 '18 at 14:23
Simon MorganSimon Morgan
1135
closed as too broad by DavidPostill♦ Dec 15 '18 at 17:54
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
add a comment |
I wrote some code for downloading podcasts and noticed that the checksums of files I downloaded with it didn't match those of files downloaded using other methods.
Initially I thought there was a bug in my code but through testing I've noticed that files downloaded using wget, curl and Invoke-WebRequest also differ from each other. I've tested on my Windows 10 PC and an Ubuntu 16.04 VPS I have and the same thing happens on both.
Does anybody have any idea what might be causing this?
http wget mp3 curl checksum
asked Dec 15 '18 at 14:23
Simon MorganSimon Morgan
1135
closed as too broad by DavidPostill♦ Dec 15 '18 at 17:54
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
add a comment |
I wrote some code for downloading podcasts and noticed that the checksums of files I downloaded with it didn't match those of files downloaded using other methods.
Initially I thought there was a bug in my code but through testing I've noticed that files downloaded using wget, curl and Invoke-WebRequest also differ from each other. I've tested on my Windows 10 PC and an Ubuntu 16.04 VPS I have and the same thing happens on both.
Does anybody have any idea what might be causing this?
http wget mp3 curl checksum
asked Dec 15 '18 at 14:23
Simon MorganSimon Morgan
1135
I wrote some code for downloading podcasts and noticed that the checksums of files I downloaded with it didn't match those of files downloaded using other methods.
Initially I thought there was a bug in my code but through testing I've noticed that files downloaded using wget, curl and Invoke-WebRequest also differ from each other. I've tested on my Windows 10 PC and an Ubuntu 16.04 VPS I have and the same thing happens on both.
Does anybody have any idea what might be causing this?
http wget mp3 curl checksum
http wget mp3 curl checksum
asked Dec 15 '18 at 14:23
Simon MorganSimon Morgan
1135
asked Dec 15 '18 at 14:23
Simon MorganSimon Morgan
1135
asked Dec 15 '18 at 14:23
Simon MorganSimon Morgan
1135
asked Dec 15 '18 at 14:23
Simon MorganSimon Morgan
1135
asked Dec 15 '18 at 14:23
Simon MorganSimon Morgan
1135
1135
closed as too broad by DavidPostill♦ Dec 15 '18 at 17:54
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
closed as too broad by DavidPostill♦ Dec 15 '18 at 17:54
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
This is most likely due to the website delivering slightly different streams to each downloader.
The difference could be due to watermarks (in case of copyrighted material often used to unique identify each download), DRM, different codecs used for encoding the audio stream, different meta-data (e.g timestamps like "downloaded on date/time") embedded in the file, etc.
answered Dec 15 '18 at 14:36
TonnyTonny
17k33353
If I download the same file multiple times using wget they all have the same checksum. If I use curl multiple times, they also have the same checksum but it's different to the wget checksum. Any ideas?
– Simon Morgan
Dec 15 '18 at 14:53
It contains the user-agent in the download? As wget isn't curl, the useragent would be different....
– djsmiley2k
Dec 15 '18 at 16:14
1
@djsmiley2k That's what I'm thinking too. The category "different meta-data" that I already mentioned.
– Tonny
Dec 15 '18 at 16:50
Using ffprobe to inspect the metadata, the only difference I can find is that the wget files are showing a different duration than the curl ones (00:29:00.72 vs 00:28:02.16). Very strange.
– Simon Morgan
Dec 15 '18 at 17:16
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
This is most likely due to the website delivering slightly different streams to each downloader.
The difference could be due to watermarks (in case of copyrighted material often used to unique identify each download), DRM, different codecs used for encoding the audio stream, different meta-data (e.g timestamps like "downloaded on date/time") embedded in the file, etc.
answered Dec 15 '18 at 14:36
TonnyTonny
17k33353
If I download the same file multiple times using wget they all have the same checksum. If I use curl multiple times, they also have the same checksum but it's different to the wget checksum. Any ideas?
– Simon Morgan
Dec 15 '18 at 14:53
It contains the user-agent in the download? As wget isn't curl, the useragent would be different....
– djsmiley2k
Dec 15 '18 at 16:14
1
@djsmiley2k That's what I'm thinking too. The category "different meta-data" that I already mentioned.
– Tonny
Dec 15 '18 at 16:50
Using ffprobe to inspect the metadata, the only difference I can find is that the wget files are showing a different duration than the curl ones (00:29:00.72 vs 00:28:02.16). Very strange.
– Simon Morgan
Dec 15 '18 at 17:16
add a comment |
This is most likely due to the website delivering slightly different streams to each downloader.
The difference could be due to watermarks (in case of copyrighted material often used to unique identify each download), DRM, different codecs used for encoding the audio stream, different meta-data (e.g timestamps like "downloaded on date/time") embedded in the file, etc.
answered Dec 15 '18 at 14:36
TonnyTonny
17k33353
If I download the same file multiple times using wget they all have the same checksum. If I use curl multiple times, they also have the same checksum but it's different to the wget checksum. Any ideas?
– Simon Morgan
Dec 15 '18 at 14:53
It contains the user-agent in the download? As wget isn't curl, the useragent would be different....
– djsmiley2k
Dec 15 '18 at 16:14
1
@djsmiley2k That's what I'm thinking too. The category "different meta-data" that I already mentioned.
– Tonny
Dec 15 '18 at 16:50
Using ffprobe to inspect the metadata, the only difference I can find is that the wget files are showing a different duration than the curl ones (00:29:00.72 vs 00:28:02.16). Very strange.
– Simon Morgan
Dec 15 '18 at 17:16
add a comment |
This is most likely due to the website delivering slightly different streams to each downloader.
The difference could be due to watermarks (in case of copyrighted material often used to unique identify each download), DRM, different codecs used for encoding the audio stream, different meta-data (e.g timestamps like "downloaded on date/time") embedded in the file, etc.
answered Dec 15 '18 at 14:36
TonnyTonny
17k33353
This is most likely due to the website delivering slightly different streams to each downloader.
The difference could be due to watermarks (in case of copyrighted material often used to unique identify each download), DRM, different codecs used for encoding the audio stream, different meta-data (e.g timestamps like "downloaded on date/time") embedded in the file, etc.
answered Dec 15 '18 at 14:36
TonnyTonny
17k33353
answered Dec 15 '18 at 14:36
TonnyTonny
17k33353
answered Dec 15 '18 at 14:36
TonnyTonny
17k33353
answered Dec 15 '18 at 14:36
TonnyTonny
17k33353
17k33353
If I download the same file multiple times using wget they all have the same checksum. If I use curl multiple times, they also have the same checksum but it's different to the wget checksum. Any ideas?
– Simon Morgan
Dec 15 '18 at 14:53
It contains the user-agent in the download? As wget isn't curl, the useragent would be different....
– djsmiley2k
Dec 15 '18 at 16:14
1
@djsmiley2k That's what I'm thinking too. The category "different meta-data" that I already mentioned.
– Tonny
Dec 15 '18 at 16:50
Using ffprobe to inspect the metadata, the only difference I can find is that the wget files are showing a different duration than the curl ones (00:29:00.72 vs 00:28:02.16). Very strange.
– Simon Morgan
Dec 15 '18 at 17:16
add a comment |
If I download the same file multiple times using wget they all have the same checksum. If I use curl multiple times, they also have the same checksum but it's different to the wget checksum. Any ideas?
– Simon Morgan
Dec 15 '18 at 14:53
It contains the user-agent in the download? As wget isn't curl, the useragent would be different....
– djsmiley2k
Dec 15 '18 at 16:14
1
@djsmiley2k That's what I'm thinking too. The category "different meta-data" that I already mentioned.
– Tonny
Dec 15 '18 at 16:50
Using ffprobe to inspect the metadata, the only difference I can find is that the wget files are showing a different duration than the curl ones (00:29:00.72 vs 00:28:02.16). Very strange.
– Simon Morgan
Dec 15 '18 at 17:16
If I download the same file multiple times using wget they all have the same checksum. If I use curl multiple times, they also have the same checksum but it's different to the wget checksum. Any ideas?
– Simon Morgan
Dec 15 '18 at 14:53
If I download the same file multiple times using wget they all have the same checksum. If I use curl multiple times, they also have the same checksum but it's different to the wget checksum. Any ideas?
– Simon Morgan
Dec 15 '18 at 14:53
It contains the user-agent in the download? As wget isn't curl, the useragent would be different....
– djsmiley2k
Dec 15 '18 at 16:14
It contains the user-agent in the download? As wget isn't curl, the useragent would be different....
– djsmiley2k
Dec 15 '18 at 16:14
1
1
@djsmiley2k That's what I'm thinking too. The category "different meta-data" that I already mentioned.
– Tonny
Dec 15 '18 at 16:50
@djsmiley2k That's what I'm thinking too. The category "different meta-data" that I already mentioned.
– Tonny
Dec 15 '18 at 16:50
Using ffprobe to inspect the metadata, the only difference I can find is that the wget files are showing a different duration than the curl ones (00:29:00.72 vs 00:28:02.16). Very strange.
– Simon Morgan
Dec 15 '18 at 17:16
Using ffprobe to inspect the metadata, the only difference I can find is that the wget files are showing a different duration than the curl ones (00:29:00.72 vs 00:28:02.16). Very strange.
– Simon Morgan
Dec 15 '18 at 17:16
add a comment |
