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PODecode file to stream, from base64 encoded string. How to do that?
 

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  1. PODecode file to stream, from base64 encoded string. How to do that?
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    <p>I have a string, recived by my app from web-browser. String contains PNG image, and encoded to base64. </p> <p>It isn't my stupid idea, convert image to base64 string )) That doing web-broser. HTML5 canvas object doing that, when need to send image to somewhere. </p> <p>So, how to decode this string to image? </p> <p>In Delphi I written my web-server, that recives data. </p> <p>In PHP this can be solved like <a href="https://stackoverflow.com/questions/15153776/convert-base64-string-to-an-image-file">that</a>:</p> <pre><code>function base64_to_jpeg( $base64_string, $output_file ) { $ifp = fopen( $output_file, "wb" ); fwrite( $ifp, base64_decode( $base64_string) ); fclose( $ifp ); return( $output_file ); } $image = base64_to_jpeg( $my_base64_string, 'tmp.jpg' ); </code></pre> <p>but in delphi, after decoding:</p> <pre><code> if (sImg &lt;&gt; EmptyStr) then begin Coder := TIdDecoderMIME.Create(nil); MS := TMemoryStream.Create; try Coder.DecodeStream(sImg, MS); MS.SaveToFile(myDir + '1.png'); finally FreeAndNil(MS); FreeAndNil(Coder); end; end; </code></pre> <p>I have a black square of Malevich.</p> <p>Also I tried functions from EncdDesd module of RTL,</p> <pre><code> if (sImg &lt;&gt; EmptyStr) then begin MS := TMemoryStream.Create; SS := TStringStream.Create(sImg); try DecodeStream(SS, MS); MS.SaveToFile(myDir + '1.png'); finally FreeAndNil(MS); FreeAndNil(SS); end; end; </code></pre> <p>I got the same result. </p> <p>I wrote web-extension for get some info from user web-browser, and web-server using TidHTTPServer. From JS I capture the web-screenshot, and remove some data from exe, after that, I send this string to the server:</p> <pre><code>var Img = capture().toDataURL(); var Img = Img.replace('data:image/png;base64,',''); if (FLA.AddNewURL(sN,sD,sU,sI,Img)) { window.close(); } else { alert('can not establish connection!'); }; </code></pre> <p>...</p> <pre><code>AddNewURL: function (aName, aDesc,sURL, aOwnerId,aImg) { var http = new XMLHttpRequest(); var params = 'Owner=' + aOwnerId + '&amp;Name=' + aName + '&amp;Desc=' + aDesc+ '&amp;URL=' + sURL; if (aImg) { params = params +'&amp;Img='+aImg; }; http.open("POST", "http://" + this.host + ":" + this.port + "/addurl", false); http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8'); http.send(params); return (http.status === 200); }, </code></pre> <p>My web-server recives this data like that:</p> <pre><code> if (ARequestInfo.Document = '/addurl') then begin Id := ARequestInfo.Params.Values['Owner']; sName := ARequestInfo.Params.Values['Name']; sDesc := ARequestInfo.Params.Values['Desc']; sURL := ARequestInfo.Params.Values['URL']; sImg := ARequestInfo.Params.Values['Img']; RootLI := nil; LinksManager.FindByID(Id, RootLI); if Assigned(RootLI) then begin LI := TLinkItem.Create(nil); LI.name := sName; LI.Description := sDesc; LI.URL := sURL; if (sImg &lt;&gt; EmptyStr) then begin MS := TMemoryStream.Create; SS := TStringStream.Create(sImg); try DecodeStream(SS, MS); MS.SaveToFile(myDir + '1.png'); finally FreeAndNil(MS); FreeAndNil(SS); end; end; RootLI.Add(LI, True); AResponseInfo.ResponseText := 'OK'; end else AResponseInfo.ResponseText := 'FAIL'; end; </code></pre> <p>After all of that I have image, that contains only black color.</p>
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    1. USAlexandr
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      1. PODecode file to stream, from base64 encoded string. How to do that?
      1. This table or related slice is empty.
      1. VTUpMod
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      1. PODecode file to stream, from base64 encoded string. How to do that?
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    1. COWhat have you tried and what didn't work? There's plenty of resources out there explaining how to do so, and some here on Stack Overflow too. You should do your research and only ask question here when you get stumped.
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      1. PODecode file to stream, from base64 encoded string. How to do that?
      1. USJerry Dodge
    2. COI've edited my question, now.
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      1. PODecode file to stream, from base64 encoded string. How to do that?
      1. USAlexandr
    3. COMuch better, now it's an adequate question.
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      1. PODecode file to stream, from base64 encoded string. How to do that?
      1. USJerry Dodge
 

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