annotate VisualC/README.txt @ 474:c66080364dff

Most decoders now report total sample play time, now. Technically, this breaks binary compatibility with the 1.0 branch, since it extends the Sound_Sample struct, but most (all?) programs are just passing pointers allocated by SDL_sound around, and might be okay. Source-level compatibility is not broken...yet! :) --ryan. -------- Original Message -------- Subject: SDL_sound patch: Finding total length of time of sound file. Date: Sun, 26 Jan 2003 09:31:17 -0800 (PST) Hi Ryan, I am working with Eric Wing and helping him modify SDL_sound. AS part of our efforts in improving and enhancing SDL_sound, we like to submit this patch. We modified the codecs to find the total time of a sound file. Below is the explanation of the patch. The patch is appended as an attachment to this email. * MOTIVATION: We needed the ability to get the total play time of a sample (And we noticed that we're not the only ones). Since SDL_sound blocks direct access to the specific decoders, there is no way for a user to know this information short of decoding the whole thing. Because of this, we believe this will be a useful addition, even though the accuracy may not be perfect (subject to each decoder) or the information may not always be available. * CONTRIBUTORS: Wesley Leong (modified the majority of the codecs and verified the results) Eric Wing (showed everyone how to do modify codec, modified mikmod) Wang Lam (modified a handful of codecs, researched into specs and int overflow) Ahilan Anantha (modified a few codecs and helped with integer math) * GENERAL ISSUES: We chose the value to be milliseconds as an Sint32. Milliseconds because that's what Sound_Seek takes as a parameter and -1 to allow for instances/codecs where the value could not be determined. We are not sure if this is the final convention you want, so we are willing to work with you on this. We also expect the total_time field to be set on open and never again modified by SDL_sound. Users may access it directly much like the sample buffer and buffer_size. We thought about recomputing the time on DecodeAll, but since users may seek or decode small chunks first, not all the data may be there. So this is better done by the user. This may be good information to document. Currently, all the main codecs are implemented except for QuickTime.
author Ryan C. Gordon <icculus@icculus.org>
date Sat, 08 May 2004 08:19:50 +0000
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1 README
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2 2002/12/23
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4 This directory contains a Project Workspace for Visual Studio 6.
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5 It is based off the code in the CVS after the 1.0.0 release (1.0.1?).
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8 This project has options to build a DLL or static library and
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9 build playsound (dynamic or static). This project mimics the
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10 original pre-1.0.0 version which no longer works with the current
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11 code.
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13 Unlike the former package, this one contains no binaries. This
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14 will allow this project to be included in the main SDL_sound
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15 source code. You will be responsible for finding the binaries
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16 you need for each decoder. We have attempted to provide a
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17 Support pack which contains the binaries built and tested with.
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18 However, many of the binaries become quickly outdated so
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19 you may not want to depend too heavily on the Support pack.
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21 If you need the binaries, you should either copy the files to your
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22 default VisualC++ directories (both headers and libraries), or add
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23 them to your search paths, either through the Project Settings for
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24 Include and Link paths or through the global settings
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25 (Tools->Options->Directories in VC6). You need to do it both for the
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26 header files (includes) and library files. To run your final
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27 executables, you will need the DLL files in the local path
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28 or one of your Windows main DLL search paths.
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31 Issues:
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32
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33 The static playsound really isn't static. You still need the
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34 dlls for each of the codecs. You will have to tweak the project to
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35 build a true static binary and will probably require you to have
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36 static versions of all the decoder libraries.
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41 Eric Wing <ewing2121@yahoo.com>
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42 Joshua Quick <jquick@golighthouse.com>