Replay file format - Revision history

Duplode: 1990 Mindscape also uses the old format

2023-03-22T00:28:38Z

1990 Mindscape also uses the old format

← Older revision		Revision as of 02:28, 22 March 2023
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	Because the whole track and terrain are saved within a replay file, it is possible to reproduce it without having the [[track file]]. It's also straightforward to extract the track from the replay file.		Because the whole track and terrain are saved within a replay file, it is possible to reproduce it without having the [[track file]]. It's also straightforward to extract the track from the replay file.

	Two replay formats exists. The "old format", used by [[Stunts 1.0\|Stunts v1.0]] ~~(Broderbund~~) and the "new format", used by all others. They only differ in two additional bytes added to the latter, but because the physics engine does change from a version to another, the same moves will not yield the same results. Therefore, replay formats across Stunts versions are considered ''incompatible''.		Two replay formats exists. The "old format", used by the 1990 [[game versions]] (Broderbund [[Stunts 1.0\|Stunts v1.0]] and Mindscape 4D Sports Driving 1990-12-13), and the "new format", used by all others. They only differ in two additional bytes added to the latter, but because the physics engine does change from a version to another, the same moves will not yield the same results. Therefore, replay formats across Stunts versions are considered ''incompatible''.

	==Header==		==Header==

Duplode: /* Body */ Mention where the replay block begins in the new format

2023-02-16T18:37:47Z

Body: Mention where the replay block begins in the new format

← Older revision		Revision as of 20:37, 16 February 2023
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	==Body==		==Body==
	Following the header, is an exact copy of the raw original [[track file]], which takes up 1802 bytes. Right after that, the replay proper begins. One byte is dedicated to each tic. On each tic, the relevant actions (typically, key presses) are recorded:		Following the header, is an exact copy of the raw original [[track file]], which takes up 1802 bytes. Right after that, at offset 0x724 in the new format, the replay proper begins. One byte is dedicated to each tic. On each tic, the relevant actions (typically, key presses) are recorded:

	* bit 0 : Accelerate		* bit 0 : Accelerate

Duplode: moved Replay File Format to Replay file format: Capitalisation

2022-02-11T21:25:12Z

moved Replay File Format to Replay file format: Capitalisation

← Older revision	Revision as of 23:25, 11 February 2022
(No difference)

Duplode: Adjusting header byte counts.

2021-02-05T00:01:19Z

Adjusting header byte counts.

Cas: /* Header */

2019-03-26T06:59:27Z

Header

← Older revision		Revision as of 08:59, 26 March 2019
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	Using any larger number causes Stunts to try to locate a file that's not found, suggesting it is possible to create new opponents.		Using any larger number causes Stunts to try to locate a file that's not found, suggesting it is possible to create new opponents.

	'''Play frequency''' is normally 20 tics per second, but Stunts will drop this to 10 if the CPU is to slow and can't keep up. Although Stunts doesn't seem to use any other frequency, modifying this value to anything else does work. A normal replay at 20 tics per second that gets this byte modified will appear to run at a different pace. Crazy speeds are possible this way. For v1.0, only 20 tics per second can be handled. When recording a replay at 10 frames per second, it should theoretically be possible to exceed the 10 minutes maximum length, given that it takes up half as much space. In practice, what happens is that Stunts will not warn past this threshold and it will still be possible to return to the replay menu, save, load, etc. Yet, it appears that some memory overrun ''does'' occur so the game becomes unstable. In a test, Stunts ended up abnormally after a replay somewhat longer than 10 minutes ~~displaying~~ an error.		'''Play frequency''' is normally 20 tics per second, but Stunts will drop this to 10 if the CPU is to slow and can't keep up. Although Stunts doesn't seem to use any other frequency, modifying this value to anything else does work. A normal replay at 20 tics per second that gets this byte modified will appear to run at a different pace. Crazy speeds are possible this way. For v1.0, only 20 tics per second can be handled. When recording a replay at 10 frames per second, it should theoretically be possible to exceed the 10 minutes maximum length, given that it takes up half as much space. In practice, what happens is that Stunts will not warn past this threshold and it will still be possible to return to the replay menu, save, load, etc. Yet, it appears that some memory overrun ''does'' occur so the game becomes unstable. In a test, Stunts ended up abnormally after a replay somewhat longer than 10 minutes with an error: ''locateshape - car0 SHAPE NOT FOUND // locatesound - n-Ti SOUND NOT FOUND // reservememory - OUT OF MEMORY RESERVING t P=2e75 HW=cbe0''.

	==Body==		==Body==

Cas: /* Header */

2019-03-26T06:54:08Z

Header

← Older revision		Revision as of 08:54, 26 March 2019
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	Using any larger number causes Stunts to try to locate a file that's not found, suggesting it is possible to create new opponents.		Using any larger number causes Stunts to try to locate a file that's not found, suggesting it is possible to create new opponents.

	'''Play frequency''' is normally 20 tics per second, but Stunts will drop this to 10 if the CPU is to slow and can't keep up. Although Stunts doesn't seem to use any other frequency, modifying this value to anything else does work. A normal replay at 20 tics per second that gets this byte modified will appear to run at a different pace. Crazy speeds are possible this way. For v1.0, only 20 tics per second can be handled.		'''Play frequency''' is normally 20 tics per second, but Stunts will drop this to 10 if the CPU is to slow and can't keep up. Although Stunts doesn't seem to use any other frequency, modifying this value to anything else does work. A normal replay at 20 tics per second that gets this byte modified will appear to run at a different pace. Crazy speeds are possible this way. For v1.0, only 20 tics per second can be handled. When recording a replay at 10 frames per second, it should theoretically be possible to exceed the 10 minutes maximum length, given that it takes up half as much space. In practice, what happens is that Stunts will not warn past this threshold and it will still be possible to return to the replay menu, save, load, etc. Yet, it appears that some memory overrun ''does'' occur so the game becomes unstable. In a test, Stunts ended up abnormally after a replay somewhat longer than 10 minutes displaying an error.

	==Body==		==Body==

Cas: /* Overview */

2019-03-26T06:48:35Z

Overview

← Older revision		Revision as of 08:48, 26 March 2019
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	==Overview==		==Overview==
	Replays are saved by Stunts as binary files of extension ''.rpl''. They contain the necessary information to recreate the actions by the player on one track, with one car and to identify the opponent. Replays are always saved from the start of the race. It's not possible to have a replay starting any later. All moves made by the player are saved up to a maximum of ten minutes at maximum quality (20 frames per second). It is not yet tested whether it's possible to save a longer time while using a lower quality (say, 20 minutes at 10 frames per second). Evidence so far suggests that is cannot be done and that the maximum time is fixed at ten minutes.		Replays are saved by Stunts as binary files of extension ''.rpl''. They contain the necessary information to recreate the actions by the player on one track, with one car and to identify the opponent. Replays are always saved from the start of the race. It's not possible to have a replay starting any later. All moves made by the player are saved up to a maximum of ten minutes at maximum quality (20 frames per second).

	Actions by the opponent (if any) are not saved. Stunts will reproduce the opponent's AI during the execution of the replay instead. This means that, if a custom AI were created, the AI file should be passed along with the replay if there are opponent moves expected to be shown with accuracy.		Actions by the opponent (if any) are not saved. Stunts will reproduce the opponent's AI during the execution of the replay instead. This means that, if a custom AI were created, the AI file should be passed along with the replay if there are opponent moves expected to be shown with accuracy.

Cas: /* Overview */

2019-03-26T04:02:28Z

Overview

← Older revision		Revision as of 06:02, 26 March 2019
Line 2:		Line 2:

	==Overview==		==Overview==
	Replays are saved by Stunts as binary files of extension ''.rpl''. They contain the necessary information to recreate the actions by the player on one track, with one car and to identify the opponent. Replays are always saved from the start of the race. It's not possible to have a replay starting any later. All moves made by the player are saved up to a maximum of ten minutes at maximum quality (20 frames per second). It is not yet tested whether it's possible to save a longer time while using a lower quality (say, 20 minutes at 10 frames per second).		Replays are saved by Stunts as binary files of extension ''.rpl''. They contain the necessary information to recreate the actions by the player on one track, with one car and to identify the opponent. Replays are always saved from the start of the race. It's not possible to have a replay starting any later. All moves made by the player are saved up to a maximum of ten minutes at maximum quality (20 frames per second). It is not yet tested whether it's possible to save a longer time while using a lower quality (say, 20 minutes at 10 frames per second). Evidence so far suggests that is cannot be done and that the maximum time is fixed at ten minutes.

	Actions by the opponent (if any) are not saved. Stunts will reproduce the opponent's AI during the execution of the replay instead. This means that, if a custom AI were created, the AI file should be passed along with the replay if there are opponent moves expected to be shown with accuracy.		Actions by the opponent (if any) are not saved. Stunts will reproduce the opponent's AI during the execution of the replay instead. This means that, if a custom AI were created, the AI file should be passed along with the replay if there are opponent moves expected to be shown with accuracy.

Cas: /* Calculating the replay length in time */

2019-03-26T03:59:45Z

Calculating the replay length in time

← Older revision		Revision as of 05:59, 26 March 2019
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	Dividing the number of ticks in the replay by the frequency (which is always 20 for the old format and is specified in the new format), we get the number of seconds (with decimals) that correspond to the total length of the replay. This is not necessarily the same as the racing time. Normally, if the race is completed and the game is allowed to record till the end, the replay will be exactly one second more than the racing time. However, if the player crashed or interrupted the replay, this difference will not hold.		Dividing the number of ticks in the replay by the frequency (which is always 20 for the old format and is specified in the new format), we get the number of seconds (with decimals) that correspond to the total length of the replay. This is not necessarily the same as the racing time. Normally, if the race is completed and the game is allowed to record till the end, the replay will be exactly one second more than the racing time. However, if the player crashed or interrupted the replay, this difference will not hold.

	A hint to whether the replay ended in the player completing the race can be ~~gather~~ by examining the bytes that compose the last second (last 20 bytes for a frequency of 20). If the replay ended normally (getting to the start/finish line and allowing the recording to complete), then all these bytes should be zero. Yet, there is a chance that the player simply didn't press any key in the last second of his recording. For this reason, the only way to be certain is to actually have a human watch the replay.		A hint to whether the replay ended with the player completing the race can be gathered by examining the bytes that compose the last second (last 20 bytes for a frequency of 20). If the replay ended normally (getting to the start/finish line and allowing the recording to complete), then all these bytes should be zero, as Stunts ignores and does not record any key presses after having crossed the finish line. Yet, there is a chance that the player simply didn't press any key in the last second of his recording. For this reason, the only way to be certain is to actually have a human watch the replay.

	[[Category:Modding]]		[[Category:Modding]]
	[[Category:Internals]]		[[Category:Internals]]

Cas: /* Overview */

2019-03-26T03:51:50Z

Overview

← Older revision		Revision as of 05:51, 26 March 2019
Line 4:		Line 4:
	Replays are saved by Stunts as binary files of extension ''.rpl''. They contain the necessary information to recreate the actions by the player on one track, with one car and to identify the opponent. Replays are always saved from the start of the race. It's not possible to have a replay starting any later. All moves made by the player are saved up to a maximum of ten minutes at maximum quality (20 frames per second). It is not yet tested whether it's possible to save a longer time while using a lower quality (say, 20 minutes at 10 frames per second).		Replays are saved by Stunts as binary files of extension ''.rpl''. They contain the necessary information to recreate the actions by the player on one track, with one car and to identify the opponent. Replays are always saved from the start of the race. It's not possible to have a replay starting any later. All moves made by the player are saved up to a maximum of ten minutes at maximum quality (20 frames per second). It is not yet tested whether it's possible to save a longer time while using a lower quality (say, 20 minutes at 10 frames per second).

	Actions by the opponent (if any) are not saved. Stunts will reproduce the opponent's AI during the execution of the replay instead.		Actions by the opponent (if any) are not saved. Stunts will reproduce the opponent's AI during the execution of the replay instead. This means that, if a custom AI were created, the AI file should be passed along with the replay if there are opponent moves expected to be shown with accuracy.

	Because the whole track and terrain are saved within a replay file, it is possible to reproduce it without having the [[track file]]. It's also straightforward to extract the track from the replay file.		Because the whole track and terrain are saved within a replay file, it is possible to reproduce it without having the [[track file]]. It's also straightforward to extract the track from the replay file.

	Two replay formats exists. The "old format", used by [[Stunts 1.0\|Stunts v1.0]] (Broderbund) and the "new format", used by all others. They only differ in two additional bytes added to the latter.		Two replay formats exists. The "old format", used by [[Stunts 1.0\|Stunts v1.0]] (Broderbund) and the "new format", used by all others. They only differ in two additional bytes added to the latter, but because the physics engine does change from a version to another, the same moves will not yield the same results. Therefore, replay formats across Stunts versions are considered ''incompatible''.

	==Header==		==Header==

← Older revision		Revision as of 02:01, 5 February 2021
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	* (1 byte) Tranmission of opponent's car (0 = manual, 1 = automatic)		* (1 byte) Tranmission of opponent's car (0 = manual, 1 = automatic)
	* (9 bytes) Name of the track file used to record, right padded with null bytes		* (9 bytes) Name of the track file used to record, right padded with null bytes
	* (1 ~~byte~~) Play frequency (tics per second) ~~<<-- Not present in v1.0~~		* (1 word) Play frequency (tics per second) <<-- Not present in v1.0
	* (1 byte) Ignored, always zero <<-- Not present in v1.0
	* (1 word) Number of ticks in replay		* (1 word) Number of ticks in replay

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	One could use a simple method to very accurately assert on which format the replay is:		One could use a simple method to very accurately assert on which format the replay is:
	* Assume new format and read the word that should contain the number of ticks		* Assume new format and read the word that should contain the number of ticks
	* Add to this number 25, for the header length and 1802, for the track length		* Add to this number 26, for the header length and 1802, for the track length
	* Compare with the replay file length. If equal, it's a new format replay file		* Compare with the replay file length. If equal, it's a new format replay file
	* Otherwise, now assume old format and read the word again at position two bytes before		* Otherwise, now assume old format and read the word again at position two bytes before
	* Add 23, for the header length and 1802, for the track length		* Add 24, for the header length and 1802, for the track length
	* Again, compare with the replay file lenght. If equal, it's an old format replay file		* Again, compare with the replay file lenght. If equal, it's an old format replay file
	* Otherwise, there's something wrong with this file		* Otherwise, there's something wrong with this file