Improved AV Reading/Writing

FFMediaToolkit/Common/ContainerMetadata.cs

@@ -1,7 +1,7 @@
 namespace FFMediaToolkit.Common
 {
-    using FFmpeg.AutoGen;
     using System.Collections.Generic;
+    using FFmpeg.AutoGen;
 
     /// <summary>
     /// Represents multimedia file metadata info.

FFMediaToolkit/Common/Internal/AudioFrame.cs

@@ -1,4 +1,5 @@
-namespace FFMediaToolkit.Common.Internal {
+namespace FFMediaToolkit.Common.Internal
+{
     using System;
     using FFMediaToolkit.Helpers;
     using FFmpeg.AutoGen;
@@ -40,7 +41,7 @@ public AudioFrame(AVFrame* frame)
         /// <summary>
         /// Gets the audio sample format.
         /// </summary>
-        public AVSampleFormat SampleFormat => Pointer != null ? (AVSampleFormat) Pointer->format : AVSampleFormat.AV_SAMPLE_FMT_NONE;
+        public AVSampleFormat SampleFormat => Pointer != null ? (AVSampleFormat)Pointer->format : AVSampleFormat.AV_SAMPLE_FMT_NONE;
 
         /// <summary>
         /// Creates an audio frame with given dimensions and allocates a buffer for it.

FFMediaToolkit/Common/Internal/MediaPacket.cs

@@ -48,12 +48,11 @@ public int StreamIndex
         /// <summary>
         /// Allocates a new empty packet.
         /// </summary>
-        /// <param name="streamIndex">The packet stream index.</param>
         /// <returns>The new <see cref="MediaPacket"/>.</returns>
-        public static MediaPacket AllocateEmpty(int streamIndex)
+        public static MediaPacket AllocateEmpty()
         {
             var packet = ffmpeg.av_packet_alloc();
-            packet->stream_index = streamIndex;
+            packet->stream_index = -1;
             return new MediaPacket(packet);
         }
 

FFMediaToolkit/Common/Internal/VideoFrame.cs

@@ -91,7 +91,6 @@ public ImageData ToBitmap(ImageConverter converter, ImagePixelFormat targetForma
             return bitmap;
         }
 
-
         /// <inheritdoc/>
         internal override unsafe void Update(AVFrame* newFrame)
         {

FFMediaToolkit/Common/Internal/MediaType.cs → FFMediaToolkit/Common/MediaType.cs

@@ -1,9 +1,9 @@
-namespace FFMediaToolkit.Common.Internal
+namespace FFMediaToolkit.Common
 {
     /// <summary>
     /// Represents the multimedia stream types.
     /// </summary>
-    internal enum MediaType
+    public enum MediaType
     {
         /// <summary>
         /// Other media type not supported by the FFMediaToolkit.

FFMediaToolkit/Decoding/AudioStream.cs

@@ -1,126 +1,93 @@
 namespace FFMediaToolkit.Decoding
 {
     using System;
+    using System.IO;
     using FFMediaToolkit.Audio;
     using FFMediaToolkit.Common.Internal;
     using FFMediaToolkit.Decoding.Internal;
-    using FFMediaToolkit.Helpers;
-    using FFmpeg.AutoGen;
 
     /// <summary>
     /// Represents an audio stream in the <see cref="MediaFile"/>.
     /// </summary>
-    public class AudioStream : IDisposable
+    public class AudioStream : MediaStream
     {
-        private readonly Decoder<AudioFrame> stream;
-        private readonly AudioFrame frame;
-        private readonly MediaOptions mediaOptions;
-
-        private readonly object syncLock = new object();
-
         /// <summary>
         /// Initializes a new instance of the <see cref="AudioStream"/> class.
         /// </summary>
-        /// <param name="audio">The Audio stream.</param>
+        /// <param name="stream">The audio stream.</param>
         /// <param name="options">The decoder settings.</param>
-        internal AudioStream(Decoder<AudioFrame> audio, MediaOptions options)
+        internal AudioStream(Decoder stream, MediaOptions options)
+            : base(stream, options)
         {
-            stream = audio;
-            mediaOptions = options;
-            frame = AudioFrame.CreateEmpty();
         }
 
         /// <summary>
         /// Gets informations about this stream.
         /// </summary>
-        public AudioStreamInfo Info => (AudioStreamInfo)stream.Info;
+        public new AudioStreamInfo Info => base.Info as AudioStreamInfo;
 
         /// <summary>
-        /// Gets the index of the next frame in the Audio stream.
+        /// Reads the next frame from the audio stream.
         /// </summary>
-        public int FramePosition { get; private set; }
-
-        /// <summary>
-        /// Gets the timestamp of the next frame in the Audio stream.
-        /// </summary>
-        public TimeSpan Position => FramePosition.ToTimeSpan(Info.AvgFrameRate);
-
-        /// <summary>
-        /// Reads the specified audio frame (chunk of audio samples sized by ffmedia settings).
-        /// </summary>
-        /// <param name="frameNumber">The frame index (zero-based number).</param>
-        /// <returns>The decoded audio frame.</returns>
-        public AudioData ReadFrame(int frameNumber)
+        /// <returns>The decoded audio data.</returns>
+        public new AudioData GetNextFrame()
         {
-            lock (syncLock)
-            {
-                frameNumber = frameNumber.Clamp(0, Info.FrameCount != 0 ? Info.FrameCount - 1 : int.MaxValue);
-
-                if (frameNumber == FramePosition)
-                {
-                    return GetNextFrameData();
-                }
-                else if (frameNumber == FramePosition - 1)
-                {
-                    return new AudioData(stream.RecentlyDecodedFrame);
-                }
-                else
-                {
-                    var frame = SeekToFrame(frameNumber);
-                    FramePosition = frameNumber + 1;
-
-                    return new AudioData(frame);
-                }
-            }
+            var frame = base.GetNextFrame() as AudioFrame;
+            return new AudioData(frame);
         }
 
         /// <summary>
-        /// Reads the audio frame found at the specified timestamp.
-        /// </summary>
-        /// <param name="targetTime">The frame timestamp.</param>
-        /// <returns>The decoded audio frame.</returns>
-        public AudioData ReadFrame(TimeSpan targetTime) => ReadFrame((int)(targetTime.TotalSeconds * Info.AvgFrameRate));
-
-        /// <summary>
-        /// Reads the next frame from this stream.
+        /// Reads the next frame from the audio stream.
+        /// A <see langword="false"/> return value indicates that reached end of stream.
+        /// The method throws exception if another error has occurred.
         /// </summary>
-        /// <returns>The decoded audio frame.</returns>
-        public AudioData ReadNextFrame()
+        /// <param name="data">The decoded audio data.</param>
+        /// <returns><see langword="false"/> if reached end of the stream.</returns>
+        public bool TryGetNextFrame(out AudioData data)
         {
-            lock (syncLock)
+            try
             {
-              return GetNextFrameData();
+                data = GetNextFrame();
+                return true;
             }
-        }
-
-        /// <inheritdoc/>
-        void IDisposable.Dispose()
-        {
-            lock (syncLock)
+            catch (EndOfStreamException)
             {
-                stream.Dispose();
-                frame.Dispose();
+                data = default;
+                return false;
             }
         }
 
-        private AudioData GetNextFrameData()
+        /// <summary>
+        /// Reads the video frame found at the specified timestamp.
+        /// </summary>
+        /// <param name="time">The frame timestamp.</param>
+        /// <returns>The decoded video frame.</returns>
+        public new AudioData GetFrame(TimeSpan time)
         {
-            var bmp = new AudioData(stream.GetNextFrame());
-            FramePosition++;
-            return bmp;
+            var frame = base.GetFrame(time) as AudioFrame;
+            return new AudioData(frame);
         }
 
-        private AudioFrame SeekToFrame(int frameNumber)
+        /// <summary>
+        /// Reads the audio data found at the specified timestamp.
+        /// A <see langword="false"/> return value indicates that reached end of stream.
+        /// The method throws exception if another error has occurred.
+        /// </summary>
+        /// <param name="time">The frame timestamp.</param>
+        /// <param name="data">The decoded audio data.</param>
+        /// <returns><see langword="false"/> if reached end of the stream.</returns>
+        public bool TryGetFrame(TimeSpan time, out AudioData data)
         {
-            var ts = frameNumber * Info.AvgNumSamplesPerFrame;
-
-            if (frameNumber < FramePosition || frameNumber > FramePosition + mediaOptions.AudioSeekThreshold)
+            try
             {
-                stream.OwnerFile.SeekFile(ts, Info.Index);
+                data = GetFrame(time);
+                return true;
+            }
+            catch (EndOfStreamException)
+            {
+                data = default;
+                return false;
             }
-
-            stream.SkipFrames(ts);
-            return stream.RecentlyDecodedFrame;
         }
     }
 }

FFMediaToolkit/Decoding/AudioStreamInfo.cs

@@ -0,0 +1,57 @@
+namespace FFMediaToolkit.Decoding
+{
+    using System;
+    using FFMediaToolkit.Common;
+    using FFMediaToolkit.Decoding.Internal;
+    using FFMediaToolkit.Helpers;
+    using FFmpeg.AutoGen;
+
+    /// <summary>
+    /// Represents informations about the audio stream.
+    /// </summary>
+    public class AudioStreamInfo : StreamInfo
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AudioStreamInfo"/> class.
+        /// </summary>
+        /// <param name="stream">A generic stream.</param>
+        /// <param name="container">The input container.</param>
+        internal unsafe AudioStreamInfo(AVStream* stream, InputContainer container)
+             : base(stream, MediaType.Audio, container)
+        {
+            var codec = stream->codec;
+            NumChannels = codec->channels;
+            SampleRate = codec->sample_rate;
+            long num_samples = stream->duration >= 0 ? stream->duration : container.Pointer->duration;
+            AvgNumSamplesPerFrame = (int)Math.Round((double)num_samples / NumberOfFrames.Value);
+            SampleFormat = codec->sample_fmt.FormatEnum(14);
+            AvSampleFormat = codec->sample_fmt;
+        }
+
+        /// <summary>
+        /// Gets the number of audio channels stored in the stream.
+        /// </summary>
+        public int NumChannels { get; }
+
+        /// <summary>
+        /// Gets the number of samples per second of the audio stream.
+        /// </summary>
+        public int SampleRate { get; }
+
+        /// <summary>
+        /// Gets the average number of samples per frame (chunk of samples) calculated from metadata.
+        /// It is used to calculate timestamps in the internal decoder methods.
+        /// </summary>
+        public int AvgNumSamplesPerFrame { get; }
+
+        /// <summary>
+        /// Gets a lowercase string representing the audio sample format.
+        /// </summary>
+        public string SampleFormat { get; }
+
+        /// <summary>
+        /// Gets the audio sample format.
+        /// </summary>
+        internal AVSampleFormat AvSampleFormat { get; }
+    }
+}