avformat/avio: Move internal AVIOContext fields to avio_internal.h

Currently AVIOContext's private fields are all over AVIOContext.
This commit moves them into a new structure in avio_internal.h instead.
Said structure contains the public AVIOContext as its first element
in order to avoid having to allocate a separate AVIOContextInternal
which is costly for those use cases where one just wants to access
an already existing buffer via the AVIOContext-API.
For these cases ffio_init_context() can't fail and always returned zero,
which was typically not checked. Therefore it has been made to not
return anything.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 48 insertions, 1 deletions

diff --git a/libavformat/avio_internal.h b/libavformat/avio_internal.h
index de95b43bdb..8b9e048f73 100644
--- a/libavformat/avio_internal.h
+++ b/libavformat/avio_internal.h
@@ -26,7 +26,54 @@
 
 extern const AVClass ff_avio_class;
 
-int ffio_init_context(AVIOContext *s,
+typedef struct FFIOContext {
+    AVIOContext pub;
+    /**
+     * A callback that is used instead of short_seek_threshold.
+     */
+    int (*short_seek_get)(void *opaque);
+
+    /**
+     * Threshold to favor readahead over seek.
+     */
+    int short_seek_threshold;
+
+    enum AVIODataMarkerType current_type;
+    int64_t last_time;
+
+    /**
+     * max filesize, used to limit allocations
+     */
+    int64_t maxsize;
+
+    /**
+     * Bytes read statistic
+     */
+    int64_t bytes_read;
+
+    /**
+     * seek statistic
+     */
+    int seek_count;
+
+    /**
+     * writeout statistic
+     */
+    int writeout_count;
+
+    /**
+     * Original buffer size
+     * used after probing to ensure seekback and to reset the buffer size
+     */
+    int orig_buffer_size;
+} FFIOContext;
+
+static av_always_inline FFIOContext *ffiocontext(AVIOContext *ctx)
+{
+    return (FFIOContext*)ctx;
+}
+
+void ffio_init_context(FFIOContext *s,
                   unsigned char *buffer,
                   int buffer_size,
                   int write_flag,