LibMedia: Move FFmpegIOContext into it's own file

This allows it to be reused for video.

Libraries/LibMedia/Audio/FFmpegLoader.cpp

@@ -19,73 +19,7 @@ namespace Audio {
 
 static constexpr int BUFFER_MAX_PROBE_SIZE = 64 * KiB;
 
-FFmpegIOContext::FFmpegIOContext(AVIOContext* avio_context)
+FFmpegLoaderPlugin::FFmpegLoaderPlugin(NonnullOwnPtr<SeekableStream> stream, NonnullOwnPtr<Media::FFmpeg::FFmpegIOContext> io_context)
-    : m_avio_context(avio_context)
-{
-}
-
-FFmpegIOContext::~FFmpegIOContext()
-{
-    // NOTE: free the buffer inside the AVIO context, since it might be changed since its initial allocation
-    av_free(m_avio_context->buffer);
-    avio_context_free(&m_avio_context);
-}
-
-ErrorOr<NonnullOwnPtr<FFmpegIOContext>> FFmpegIOContext::create(AK::SeekableStream& stream)
-{
-    auto* avio_buffer = av_malloc(PAGE_SIZE);
-    if (avio_buffer == nullptr)
-        return Error::from_string_literal("Failed to allocate AVIO buffer");
-
-    // This AVIOContext explains to avformat how to interact with our stream
-    auto* avio_context = avio_alloc_context(
-        static_cast<unsigned char*>(avio_buffer),
-        PAGE_SIZE,
-        0,
-        &stream,
-        [](void* opaque, u8* buffer, int size) -> int {
-            auto& stream = *static_cast<SeekableStream*>(opaque);
-            AK::Bytes buffer_bytes { buffer, AK::min<size_t>(size, PAGE_SIZE) };
-            auto read_bytes_or_error = stream.read_some(buffer_bytes);
-            if (read_bytes_or_error.is_error()) {
-                if (read_bytes_or_error.error().code() == EOF)
-                    return AVERROR_EOF;
-                return AVERROR_UNKNOWN;
-            }
-            int number_of_bytes_read = read_bytes_or_error.value().size();
-            if (number_of_bytes_read == 0)
-                return AVERROR_EOF;
-            return number_of_bytes_read;
-        },
-        nullptr,
-        [](void* opaque, int64_t offset, int whence) -> int64_t {
-            whence &= ~AVSEEK_FORCE;
-
-            auto& stream = *static_cast<SeekableStream*>(opaque);
-            if (whence == AVSEEK_SIZE)
-                return static_cast<int64_t>(stream.size().value());
-
-            auto seek_mode_from_whence = [](int origin) -> SeekMode {
-                if (origin == SEEK_CUR)
-                    return SeekMode::FromCurrentPosition;
-                if (origin == SEEK_END)
-                    return SeekMode::FromEndPosition;
-                return SeekMode::SetPosition;
-            };
-            auto offset_or_error = stream.seek(offset, seek_mode_from_whence(whence));
-            if (offset_or_error.is_error())
-                return -EIO;
-            return 0;
-        });
-    if (avio_context == nullptr) {
-        av_free(avio_buffer);
-        return Error::from_string_literal("Failed to allocate AVIO context");
-    }
-
-    return make<FFmpegIOContext>(avio_context);
-}
-
-FFmpegLoaderPlugin::FFmpegLoaderPlugin(NonnullOwnPtr<SeekableStream> stream, NonnullOwnPtr<FFmpegIOContext> io_context)
     : LoaderPlugin(move(stream))
     , m_io_context(move(io_context))
 {
@@ -105,7 +39,7 @@ FFmpegLoaderPlugin::~FFmpegLoaderPlugin()
 
 ErrorOr<NonnullOwnPtr<LoaderPlugin>> FFmpegLoaderPlugin::create(NonnullOwnPtr<SeekableStream> stream)
 {
-    auto io_context = TRY(FFmpegIOContext::create(*stream));
+    auto io_context = TRY(Media::FFmpeg::FFmpegIOContext::create(*stream));
     auto loader = make<FFmpegLoaderPlugin>(move(stream), move(io_context));
     TRY(loader->initialize());
     return loader;
@@ -180,7 +114,7 @@ double FFmpegLoaderPlugin::time_base() const
 
 bool FFmpegLoaderPlugin::sniff(SeekableStream& stream)
 {
-    auto io_context = MUST(FFmpegIOContext::create(stream));
+    auto io_context = MUST(Media::FFmpeg::FFmpegIOContext::create(stream));
 #ifdef USE_CONSTIFIED_POINTERS
     AVInputFormat const* detected_format {};
 #else

Libraries/LibMedia/Audio/FFmpegLoader.h

@@ -9,6 +9,7 @@
 #include "Loader.h"
 #include <AK/Error.h>
 #include <AK/NonnullOwnPtr.h>
+#include <LibMedia/FFmpeg/FFmpegIOContext.h>
 
 extern "C" {
 #include <libavcodec/avcodec.h>
@@ -17,22 +18,9 @@ extern "C" {
 
 namespace Audio {
 
-class FFmpegIOContext {
-public:
-    explicit FFmpegIOContext(AVIOContext*);
-    ~FFmpegIOContext();
-
-    static ErrorOr<NonnullOwnPtr<FFmpegIOContext>> create(AK::SeekableStream& stream);
-
-    AVIOContext* avio_context() const { return m_avio_context; }
-
-private:
-    AVIOContext* m_avio_context { nullptr };
-};
-
 class FFmpegLoaderPlugin : public LoaderPlugin {
 public:
-    explicit FFmpegLoaderPlugin(NonnullOwnPtr<SeekableStream>, NonnullOwnPtr<FFmpegIOContext>);
+    explicit FFmpegLoaderPlugin(NonnullOwnPtr<SeekableStream>, NonnullOwnPtr<Media::FFmpeg::FFmpegIOContext>);
     virtual ~FFmpegLoaderPlugin();
 
     static bool sniff(SeekableStream& stream);
@@ -58,7 +46,7 @@ private:
     AVCodecContext* m_codec_context { nullptr };
     AVFormatContext* m_format_context { nullptr };
     AVFrame* m_frame { nullptr };
-    NonnullOwnPtr<FFmpegIOContext> m_io_context;
+    NonnullOwnPtr<Media::FFmpeg::FFmpegIOContext> m_io_context;
     int m_loaded_samples { 0 };
     AVPacket* m_packet { nullptr };
     int m_total_samples { 0 };

Libraries/LibMedia/CMakeLists.txt

@@ -22,6 +22,7 @@ target_link_libraries(LibMedia PRIVATE LibCore LibCrypto LibRIFF LibIPC LibGfx L
 if (NOT ANDROID)
     target_sources(LibMedia PRIVATE
             Audio/FFmpegLoader.cpp
+            FFmpeg/FFmpegIOContext.cpp
             FFmpeg/FFmpegVideoDecoder.cpp
     )
     target_link_libraries(LibMedia PRIVATE PkgConfig::AVCODEC PkgConfig::AVFORMAT PkgConfig::AVUTIL)

Libraries/LibMedia/FFmpeg/FFmpegIOContext.cpp

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Stream.h>
+#include <LibMedia/FFmpeg/FFmpegIOContext.h>
+
+namespace Media::FFmpeg {
+
+FFmpegIOContext::FFmpegIOContext(AVIOContext* avio_context)
+    : m_avio_context(avio_context)
+{
+}
+
+FFmpegIOContext::~FFmpegIOContext()
+{
+    // NOTE: free the buffer inside the AVIO context, since it might be changed since its initial allocation
+    av_free(m_avio_context->buffer);
+    avio_context_free(&m_avio_context);
+}
+
+ErrorOr<NonnullOwnPtr<FFmpegIOContext>> FFmpegIOContext::create(AK::SeekableStream& stream)
+{
+    auto* avio_buffer = av_malloc(PAGE_SIZE);
+    if (avio_buffer == nullptr)
+        return Error::from_string_literal("Failed to allocate AVIO buffer");
+
+    // This AVIOContext explains to avformat how to interact with our stream
+    auto* avio_context = avio_alloc_context(
+        static_cast<unsigned char*>(avio_buffer),
+        PAGE_SIZE,
+        0,
+        &stream,
+        [](void* opaque, u8* buffer, int size) -> int {
+            auto& stream = *static_cast<SeekableStream*>(opaque);
+            AK::Bytes buffer_bytes { buffer, AK::min<size_t>(size, PAGE_SIZE) };
+            auto read_bytes_or_error = stream.read_some(buffer_bytes);
+            if (read_bytes_or_error.is_error()) {
+                if (read_bytes_or_error.error().code() == EOF)
+                    return AVERROR_EOF;
+                return AVERROR_UNKNOWN;
+            }
+            int number_of_bytes_read = read_bytes_or_error.value().size();
+            if (number_of_bytes_read == 0)
+                return AVERROR_EOF;
+            return number_of_bytes_read;
+        },
+        nullptr,
+        [](void* opaque, int64_t offset, int whence) -> int64_t {
+            whence &= ~AVSEEK_FORCE;
+
+            auto& stream = *static_cast<SeekableStream*>(opaque);
+            if (whence == AVSEEK_SIZE)
+                return static_cast<int64_t>(stream.size().value());
+
+            auto seek_mode_from_whence = [](int origin) -> SeekMode {
+                if (origin == SEEK_CUR)
+                    return SeekMode::FromCurrentPosition;
+                if (origin == SEEK_END)
+                    return SeekMode::FromEndPosition;
+                return SeekMode::SetPosition;
+            };
+            auto offset_or_error = stream.seek(offset, seek_mode_from_whence(whence));
+            if (offset_or_error.is_error())
+                return -EIO;
+            return 0;
+        });
+    if (avio_context == nullptr) {
+        av_free(avio_buffer);
+        return Error::from_string_literal("Failed to allocate AVIO context");
+    }
+
+    return make<FFmpegIOContext>(avio_context);
+}
+
+}

Libraries/LibMedia/FFmpeg/FFmpegIOContext.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Error.h>
+#include <AK/NonnullOwnPtr.h>
+
+extern "C" {
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+}
+
+namespace Media::FFmpeg {
+
+class FFmpegIOContext {
+public:
+    explicit FFmpegIOContext(AVIOContext*);
+    ~FFmpegIOContext();
+
+    static ErrorOr<NonnullOwnPtr<FFmpegIOContext>> create(AK::SeekableStream& stream);
+
+    AVIOContext* avio_context() const { return m_avio_context; }
+
+private:
+    AVIOContext* m_avio_context { nullptr };
+};
+
+}