Fixed ffmpeg cover art not showing on android as discussed.

AaxDecrypter/AaxcDownloadConverter.cs

@@ -132,8 +132,7 @@ namespace AaxDecrypter
 
         public bool Step2_DownloadAndCombine()
         {
-
+            var aaxcProcesser = new FFMpegAaxcProcesser(downloadLicense);
-            var aaxcProcesser = new FFMpegAaxcProcesser(DecryptSupportLibraries.ffmpegPath);
             aaxcProcesser.ProgressUpdate += AaxcProcesser_ProgressUpdate;
 
             string metadataPath = null;
@@ -147,10 +146,6 @@ namespace AaxDecrypter
             }
 
             aaxcProcesser.ProcessBook(
-                downloadLicense.DownloadUrl,
-                downloadLicense.UserAgent,
-                downloadLicense.AudibleKey,
-                downloadLicense.AudibleIV,
                 outputFileName,
                 metadataPath)
                 .GetAwaiter()
@@ -172,9 +167,8 @@ namespace AaxDecrypter
         }
 
         /// <summary>
-        /// Copy all aacx metadata to m4b file.
+        /// Copy all aacx metadata to m4b file, including cover art.
         /// </summary>
-        /// <returns></returns>
         public bool Step3_RestoreMetadata()
         {
             var outFile = new TagLib.Mpeg4.File(outputFileName, TagLib.ReadStyle.Average);
@@ -186,6 +180,8 @@ namespace AaxDecrypter
 
             //copy all metadata fields in the source file, even those that TagLib doesn't
             //recognize, to the output file.
+            //NOTE: Chapters aren't stored in MPEG-4 metadata. They are encoded as a Timed
+            //Text Stream (MPEG-4 Part 17), so taglib doesn't read or write them.
             foreach (var stag in sourceTag)
             {
                 destTags.SetData(stag.BoxType, stag.Children.Cast<TagLib.Mpeg4.AppleDataBox>().ToArray());

AaxDecrypter/FFMpegAaxcProcesser.cs

@@ -7,96 +7,96 @@ using System.Threading.Tasks;
 
 namespace AaxDecrypter
 {
+
     /// <summary>
-    /// Download audible aaxc, decrypt, remux,and add metadata.
+    /// Download audible aaxc, decrypt, and remux with chapters.
     /// </summary>
     class FFMpegAaxcProcesser
     {
         public event EventHandler<TimeSpan> ProgressUpdate;
         public string FFMpegPath { get; }
+        public DownloadLicense DownloadLicense { get; }
         public bool IsRunning { get; private set; }
         public bool Succeeded { get; private set; }
-        public string FFMpegStandardError => ffmpegError.ToString();
+        public string FFMpegRemuxerStandardError => remuxerError.ToString();
+        public string FFMpegDownloaderStandardError => downloaderError.ToString();
 
 
-        private StringBuilder ffmpegError = new StringBuilder();
+        private StringBuilder remuxerError = new StringBuilder();
+        private StringBuilder downloaderError = new StringBuilder();
         private static Regex processedTimeRegex = new Regex("time=(\\d{2}):(\\d{2}):(\\d{2}).\\d{2}", RegexOptions.IgnoreCase | RegexOptions.Compiled);
 
-        public FFMpegAaxcProcesser(string ffmpegPath)
+        public FFMpegAaxcProcesser( DownloadLicense downloadLicense)
         {
-            FFMpegPath = ffmpegPath;
+            FFMpegPath = DecryptSupportLibraries.ffmpegPath;
+            DownloadLicense = downloadLicense;
         }
-        public async Task ProcessBook(string aaxcUrl, string userAgent, string audibleKey, string audibleIV, string outputFile, string metadataPath = null)
+
+        public async Task ProcessBook(string outputFile, string ffmetaChaptersPath = null)
         {
             //This process gets the aaxc from the url and streams the decrypted
-            //m4b to the output file.
+            //aac stream to standard output
-            var StartInfo = new ProcessStartInfo
-            {
-                FileName = FFMpegPath,
-                RedirectStandardError = true,
-                CreateNoWindow = true,
-                WindowStyle = ProcessWindowStyle.Hidden,
-                UseShellExecute = false,
-                WorkingDirectory = Path.GetDirectoryName(FFMpegPath),
-               
-            };
-
-            if (metadataPath != null)
-            {
-                StartInfo.ArgumentList.Add("-ignore_chapters"); //prevents ffmpeg from copying chapter info from aaxc to output file
-                StartInfo.ArgumentList.Add("true");
-            }
-
-            StartInfo.ArgumentList.Add("-audible_key");
-            StartInfo.ArgumentList.Add(audibleKey);
-            StartInfo.ArgumentList.Add("-audible_iv");
-            StartInfo.ArgumentList.Add(audibleIV);
-            StartInfo.ArgumentList.Add("-user_agent");
-            StartInfo.ArgumentList.Add(userAgent);
-            StartInfo.ArgumentList.Add("-i");
-            StartInfo.ArgumentList.Add(aaxcUrl);
-
-            if (metadataPath != null)
-            {
-                StartInfo.ArgumentList.Add("-f");
-                StartInfo.ArgumentList.Add("ffmetadata");
-                StartInfo.ArgumentList.Add("-i");
-                StartInfo.ArgumentList.Add(metadataPath);
-                StartInfo.ArgumentList.Add("-map_metadata");
-                StartInfo.ArgumentList.Add("1");
-            }
-
-            StartInfo.ArgumentList.Add("-c"); //copy all codecs to output
-            StartInfo.ArgumentList.Add("copy");
-            StartInfo.ArgumentList.Add("-f"); //force output format: mp4
-            StartInfo.ArgumentList.Add("mp4");
-            StartInfo.ArgumentList.Add("-movflags"); //don't add nero format chapter flags
-            StartInfo.ArgumentList.Add("disable_chpl+faststart");
-            StartInfo.ArgumentList.Add(outputFile);
-            StartInfo.ArgumentList.Add("-y"); //overwrite existing file
-
-            await ProcessBook(StartInfo);
-        }
-
-        private async Task ProcessBook(ProcessStartInfo startInfo)
-        {
             var downloader = new Process
             {
-                StartInfo = startInfo
+                StartInfo = getDownloaderStartInfo()
+            };
+
+            //This process retreves an aac stream from standard input and muxes
+            // it into an m4b along with the cover art and metadata.
+            var remuxer = new Process
+            {
+                StartInfo = getRemuxerStartInfo(outputFile, ffmetaChaptersPath)
             };
 
             IsRunning = true;
 
-            downloader.ErrorDataReceived += Remuxer_ErrorDataReceived;
+            downloader.ErrorDataReceived += Downloader_ErrorDataReceived;
             downloader.Start();
             downloader.BeginErrorReadLine();
 
+            remuxer.ErrorDataReceived += Remuxer_ErrorDataReceived;
+            remuxer.Start();
+            remuxer.BeginErrorReadLine();
+
+            var pipedOutput = downloader.StandardOutput.BaseStream;
+            var pipedInput = remuxer.StandardInput.BaseStream;
+
+
             //All the work done here. Copy download standard output into
             //remuxer standard input
-            await downloader.WaitForExitAsync();
+            await Task.Run(() =>
+            {
+                int lastRead = 0;
+                byte[] buffer = new byte[32 * 1024];
+
+                do
+                {
+                    lastRead = pipedOutput.Read(buffer, 0, buffer.Length);
+                    pipedInput.Write(buffer, 0, lastRead);
+                } while (lastRead > 0 && !remuxer.HasExited);
+            });
+
+            //Closing input stream terminates remuxer
+            pipedInput.Close();
+
+            //If the remuxer exited due to failure, downloader will still have
+            //data in the pipe. Force kill downloader to continue.
+            if (remuxer.HasExited && !downloader.HasExited)
+                downloader.Kill();
+
+            remuxer.WaitForExit();
+            downloader.WaitForExit();
 
             IsRunning = false;
-            Succeeded = downloader.ExitCode == 0;
+            Succeeded = downloader.ExitCode == 0 && remuxer.ExitCode == 0;
+        }
+
+        private void Downloader_ErrorDataReceived(object sender, DataReceivedEventArgs e)
+        {
+            if (string.IsNullOrEmpty(e.Data))
+                return;
+
+            downloaderError.AppendLine(e.Data);            
         }
 
         private void Remuxer_ErrorDataReceived(object sender, DataReceivedEventArgs e)
@@ -104,7 +104,7 @@ namespace AaxDecrypter
             if (string.IsNullOrEmpty(e.Data))
                 return;
 
-            ffmpegError.AppendLine(e.Data);
+            remuxerError.AppendLine(e.Data);
 
             if (processedTimeRegex.IsMatch(e.Data))
             {
@@ -122,9 +122,92 @@ namespace AaxDecrypter
 
             if (e.Data.Contains("aac bitstream error"))
             {
+                //This happens if input is corrupt (should never happen) or if caller
+                //supplied wrong key/iv
                 var process = sender as Process;
                 process.Kill();
             }
         }
+
+        private ProcessStartInfo getDownloaderStartInfo() =>
+         new ProcessStartInfo
+         {
+             FileName = FFMpegPath,
+             RedirectStandardError = true,
+             RedirectStandardOutput = true,
+             CreateNoWindow = true,
+             WindowStyle = ProcessWindowStyle.Hidden,
+             UseShellExecute = false,
+             WorkingDirectory = Path.GetDirectoryName(FFMpegPath),
+             ArgumentList ={
+                    "-nostdin",
+                    "-audible_key",
+                    DownloadLicense.AudibleKey,
+                    "-audible_iv",
+                    DownloadLicense.AudibleIV,
+                    "-user_agent",
+                    DownloadLicense.UserAgent, //user-agent is requied for CDN to serve the file
+                    "-i",
+                    DownloadLicense.DownloadUrl, 
+                    "-c:a", //audio codec
+                    "copy", //copy stream
+                    "-f", //force output format: adts
+                    "adts",
+                    "pipe:" //pipe output to stdout
+                }
+         };
+
+        private ProcessStartInfo getRemuxerStartInfo(string outputFile, string ffmetaChaptersPath = null)
+        {
+           var startInfo = new ProcessStartInfo
+            {
+                FileName = FFMpegPath,
+                RedirectStandardError = true,
+                RedirectStandardInput = true,
+                CreateNoWindow = true,
+                WindowStyle = ProcessWindowStyle.Hidden,
+                UseShellExecute = false,
+                WorkingDirectory = Path.GetDirectoryName(FFMpegPath),
+            };
+
+            startInfo.ArgumentList.Add("-thread_queue_size");
+            startInfo.ArgumentList.Add("1024");
+            startInfo.ArgumentList.Add("-f"); //force input format: aac
+            startInfo.ArgumentList.Add("aac");
+            startInfo.ArgumentList.Add("-i"); //read input from stdin
+            startInfo.ArgumentList.Add("pipe:");
+
+            if (ffmetaChaptersPath is null)
+            {
+                //copy metadata from aaxc file.
+                startInfo.ArgumentList.Add("-user_agent");
+                startInfo.ArgumentList.Add(DownloadLicense.UserAgent);
+                startInfo.ArgumentList.Add("-i");
+                startInfo.ArgumentList.Add(DownloadLicense.DownloadUrl);
+            }
+            else
+            {
+                //copy metadata from supplied metadata file
+                startInfo.ArgumentList.Add("-f");
+                startInfo.ArgumentList.Add("ffmetadata");
+                startInfo.ArgumentList.Add("-i");
+                startInfo.ArgumentList.Add(ffmetaChaptersPath);
+            }
+
+            startInfo.ArgumentList.Add("-map"); //map file 0 (aac audio stream)
+            startInfo.ArgumentList.Add("0");
+            startInfo.ArgumentList.Add("-map_chapters"); //copy chapter data from file 1 (either metadata file or aaxc file)
+            startInfo.ArgumentList.Add("1");
+            startInfo.ArgumentList.Add("-c"); //copy all mapped streams
+            startInfo.ArgumentList.Add("copy");
+            startInfo.ArgumentList.Add("-f"); //force output format: mp4
+            startInfo.ArgumentList.Add("mp4");
+            startInfo.ArgumentList.Add("-movflags"); 
+            startInfo.ArgumentList.Add("disable_chpl"); //Disable Nero chapters format
+            startInfo.ArgumentList.Add(outputFile);
+            startInfo.ArgumentList.Add("-y"); //overwrite existing
+
+            return startInfo;
+        }
     }
 }