Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 508 insertions, 0 deletions

diff --git a/media/libnestegg/include/nestegg/nestegg.h b/media/libnestegg/include/nestegg/nestegg.h
new file mode 100644
index 0000000000..dc035e9d4a
--- /dev/null
+++ b/media/libnestegg/include/nestegg/nestegg.h
@@ -0,0 +1,508 @@
+/*
+ * Copyright © 2010 Mozilla Foundation
+ *
+ * This program is made available under an ISC-style license.  See the
+ * accompanying file LICENSE for details.
+ */
+#if !defined(NESTEGG_671cac2a_365d_ed69_d7a3_4491d3538d79)
+#define NESTEGG_671cac2a_365d_ed69_d7a3_4491d3538d79
+
+#include <limits.h>
+#include <stdint.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+/** @mainpage
+
+    @section intro Introduction
+
+    This is the documentation for the <tt>libnestegg</tt> C API.
+    <tt>libnestegg</tt> is a demultiplexing library for <a
+    href="http://www.webmproject.org/code/specs/container/">WebM</a>
+    media files.
+
+    @section example Example code
+
+    @code
+    nestegg * demux_ctx;
+    nestegg_init(&demux_ctx, io, NULL, -1);
+
+    nestegg_packet * pkt;
+    while ((r = nestegg_read_packet(demux_ctx, &pkt)) > 0) {
+      unsigned int track;
+
+      nestegg_packet_track(pkt, &track);
+
+      // This example decodes the first track only.
+      if (track == 0) {
+        unsigned int chunk, chunks;
+
+        nestegg_packet_count(pkt, &chunks);
+
+        // Decode each chunk of data.
+        for (chunk = 0; chunk < chunks; ++chunk) {
+          unsigned char * data;
+          size_t data_size;
+
+          nestegg_packet_data(pkt, chunk, &data, &data_size);
+
+          example_codec_decode(codec_ctx, data, data_size);
+        }
+      }
+
+      nestegg_free_packet(pkt);
+    }
+
+    nestegg_destroy(demux_ctx);
+    @endcode
+*/
+
+
+/** @file
+    The <tt>libnestegg</tt> C API. */
+
+#define NESTEGG_TRACK_VIDEO   0       /**< Track is of type video. */
+#define NESTEGG_TRACK_AUDIO   1       /**< Track is of type audio. */
+#define NESTEGG_TRACK_UNKNOWN INT_MAX /**< Track is of type unknown. */
+
+#define NESTEGG_CODEC_VP8     0       /**< Track uses Google On2 VP8 codec. */
+#define NESTEGG_CODEC_VORBIS  1       /**< Track uses Xiph Vorbis codec. */
+#define NESTEGG_CODEC_VP9     2       /**< Track uses Google On2 VP9 codec. */
+#define NESTEGG_CODEC_OPUS    3       /**< Track uses Xiph Opus codec. */
+#define NESTEGG_CODEC_AV1     4       /**< Track uses AOMedia AV1 codec. */
+#define NESTEGG_CODEC_UNKNOWN INT_MAX /**< Track uses unknown codec. */
+
+#define NESTEGG_VIDEO_MONO              0 /**< Track is mono video. */
+#define NESTEGG_VIDEO_STEREO_LEFT_RIGHT 1 /**< Track is side-by-side stereo video.  Left first. */
+#define NESTEGG_VIDEO_STEREO_BOTTOM_TOP 2 /**< Track is top-bottom stereo video.  Right first. */
+#define NESTEGG_VIDEO_STEREO_TOP_BOTTOM 3 /**< Track is top-bottom stereo video.  Left first. */
+#define NESTEGG_VIDEO_STEREO_RIGHT_LEFT 11 /**< Track is side-by-side stereo video.  Right first. */
+
+#define NESTEGG_SEEK_SET 0 /**< Seek offset relative to beginning of stream. */
+#define NESTEGG_SEEK_CUR 1 /**< Seek offset relative to current position in stream. */
+#define NESTEGG_SEEK_END 2 /**< Seek offset relative to end of stream. */
+
+#define NESTEGG_LOG_DEBUG    1     /**< Debug level log message. */
+#define NESTEGG_LOG_INFO     10    /**< Informational level log message. */
+#define NESTEGG_LOG_WARNING  100   /**< Warning level log message. */
+#define NESTEGG_LOG_ERROR    1000  /**< Error level log message. */
+#define NESTEGG_LOG_CRITICAL 10000 /**< Critical level log message. */
+
+#define NESTEGG_ENCODING_COMPRESSION 0 /**< Content encoding type is compression. */
+#define NESTEGG_ENCODING_ENCRYPTION  1 /**< Content encoding type is encryption. */
+
+#define NESTEGG_PACKET_HAS_SIGNAL_BYTE_FALSE         0 /**< Packet does not have signal byte */
+#define NESTEGG_PACKET_HAS_SIGNAL_BYTE_UNENCRYPTED   1 /**< Packet has signal byte and is unencrypted */
+#define NESTEGG_PACKET_HAS_SIGNAL_BYTE_ENCRYPTED     2 /**< Packet has signal byte and is encrypted */
+#define NESTEGG_PACKET_HAS_SIGNAL_BYTE_PARTITIONED   4 /**< Packet has signal byte and is partitioned */
+
+#define NESTEGG_PACKET_HAS_KEYFRAME_FALSE   0 /**< Packet contains only keyframes. */
+#define NESTEGG_PACKET_HAS_KEYFRAME_TRUE    1 /**< Packet does not contain any keyframes */
+#define NESTEGG_PACKET_HAS_KEYFRAME_UNKNOWN 2 /**< Packet may or may not contain keyframes */
+
+typedef struct nestegg nestegg;               /**< Opaque handle referencing the stream state. */
+typedef struct nestegg_packet nestegg_packet; /**< Opaque handle referencing a packet of data. */
+
+/** User supplied IO context. */
+typedef struct {
+  /** User supplied read callback.
+      @param buffer   Buffer to read data into.
+      @param length   Length of supplied buffer in bytes.
+      @param userdata The #userdata supplied by the user.
+      @retval  1 Read succeeded.
+      @retval  0 End of stream.
+      @retval -1 Error. */
+  int (* read)(void * buffer, size_t length, void * userdata);
+
+  /** User supplied seek callback.
+      @param offset   Offset within the stream to seek to.
+      @param whence   Seek direction.  One of #NESTEGG_SEEK_SET,
+                      #NESTEGG_SEEK_CUR, or #NESTEGG_SEEK_END.
+      @param userdata The #userdata supplied by the user.
+      @retval  0 Seek succeeded.
+      @retval -1 Error. */
+  int (* seek)(int64_t offset, int whence, void * userdata);
+
+  /** User supplied tell callback.
+      @param userdata The #userdata supplied by the user.
+      @returns Current position within the stream.
+      @retval -1 Error. */
+  int64_t (* tell)(void * userdata);
+
+  /** User supplied pointer to be passed to the IO callbacks. */
+  void * userdata;
+} nestegg_io;
+
+/** Parameters specific to a video track. */
+typedef struct {
+  unsigned int stereo_mode;    /**< Video mode.  One of #NESTEGG_VIDEO_MONO,
+                                    #NESTEGG_VIDEO_STEREO_LEFT_RIGHT,
+                                    #NESTEGG_VIDEO_STEREO_BOTTOM_TOP, or
+                                    #NESTEGG_VIDEO_STEREO_TOP_BOTTOM. */
+  unsigned int width;          /**< Width of the video frame in pixels. */
+  unsigned int height;         /**< Height of the video frame in pixels. */
+  unsigned int display_width;  /**< Display width of the video frame in pixels. */
+  unsigned int display_height; /**< Display height of the video frame in pixels. */
+  unsigned int crop_bottom;    /**< Pixels to crop from the bottom of the frame. */
+  unsigned int crop_top;       /**< Pixels to crop from the top of the frame. */
+  unsigned int crop_left;      /**< Pixels to crop from the left of the frame. */
+  unsigned int crop_right;     /**< Pixels to crop from the right of the frame. */
+  unsigned int alpha_mode;     /**< 1 if an additional opacity stream is available, otherwise 0. */
+  unsigned int matrix_coefficients;      /**< See Table 4 of ISO/IEC 23001-8:2016. */
+  unsigned int range;                    /**< Clipping of color ranges. */
+  unsigned int transfer_characteristics; /**< See Table 3 of ISO/IEC 23091-4. */
+  unsigned int primaries;                /**< See Table 2 of ISO/IEC 23091-4. */
+  double primary_r_chromacity_x;         /**< Red X chromaticity coordinate per CIE 1931.
+                                              NaN means element not present. */
+  double primary_r_chromacity_y;         /**< Red Y chromaticity coordinate per CIE 1931.
+                                              NaN means element not present. */
+  double primary_g_chromacity_x;         /**< Green X chromaticity coordinate per CIE 1931.
+                                              NaN means element not present. */
+  double primary_g_chromacity_y;         /**< Green Y chromaticity coordinate per CIE 1931.
+                                              NaN means element not present. */
+  double primary_b_chromacity_x;         /**< Blue X chromaticity coordinate per CIE 1931.
+                                              NaN means element not present. */
+  double primary_b_chromacity_y;         /**< Blue Y chromaticity coordinate per CIE 1931.
+                                              NaN means element not present. */
+  double white_point_chromaticity_x;     /**< White X chromaticity coordinate per CIE 1931.
+                                              NaN means element not present. */
+  double white_point_chromaticity_y;     /**< White Y chromaticity coordinate per CIE 1931.
+                                              NaN means element not present. */
+  double luminance_max;                  /**< Maximum luminance in cd/m2.
+                                              NaN means element not present. */
+  double luminance_min;                  /**< Minimum luminance in cd/m2.
+                                              NaN means element not present. */
+} nestegg_video_params;
+
+/** Parameters specific to an audio track. */
+typedef struct {
+  double rate;           /**< Sampling rate in Hz. */
+  unsigned int channels; /**< Number of audio channels. */
+  unsigned int depth;    /**< Bits per sample. */
+  uint64_t  codec_delay; /**< Nanoseconds that must be discarded from the start. */
+  uint64_t  seek_preroll;/**< Nanoseconds that must be discarded after a seek. */
+} nestegg_audio_params;
+
+/** Logging callback function pointer. */
+typedef void (* nestegg_log)(nestegg * context, unsigned int severity, char const * format, ...);
+
+/** Initialize a nestegg context.  During initialization the parser will
+    read forward in the stream processing all elements until the first
+    block of media is reached.  All track metadata has been processed at this point.
+    @param context  Storage for the new nestegg context.  @see nestegg_destroy
+    @param io       User supplied IO context.
+    @param callback Optional logging callback function pointer.  May be NULL.
+    @param max_offset Optional maximum offset to be read. Set -1 to ignore.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_init(nestegg ** context, nestegg_io io, nestegg_log callback, int64_t max_offset);
+
+/** Destroy a nestegg context and free associated memory.
+    @param context #nestegg context to be freed.  @see nestegg_init */
+void nestegg_destroy(nestegg * context);
+
+/** Query the duration of the media stream in nanoseconds.
+    @param context  Stream context initialized by #nestegg_init.
+    @param duration Storage for the queried duration.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_duration(nestegg * context, uint64_t * duration);
+
+/** Query the tstamp scale of the media stream in nanoseconds.
+    @note Timestamps presented by nestegg have been scaled by this value
+          before presentation to the caller.
+    @param context Stream context initialized by #nestegg_init.
+    @param scale   Storage for the queried scale factor.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_tstamp_scale(nestegg * context, uint64_t * scale);
+
+/** Query the number of tracks in the media stream.
+    @param context Stream context initialized by #nestegg_init.
+    @param tracks  Storage for the queried track count.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_track_count(nestegg * context, unsigned int * tracks);
+
+/** Query the start and end offset for a particular cluster.
+    @param context     Stream context initialized by #nestegg_init.
+    @param cluster_num Zero-based cluster number; order they appear in cues.
+    @param max_offset  Optional maximum offset to be read. Set -1 to ignore.
+    @param start_pos   Starting offset of the cluster. -1 means non-existant.
+    @param end_pos     Starting offset of the cluster. -1 means non-existant or
+                       final cluster.
+    @param tstamp      Starting timestamp of the cluster.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_get_cue_point(nestegg * context, unsigned int cluster_num,
+                          int64_t max_offset, int64_t * start_pos,
+                          int64_t * end_pos, uint64_t * tstamp);
+
+/** Seek to @a offset.  Stream will seek directly to offset.
+    Must be used to seek to the start of a cluster; the parser will not be
+    able to understand other offsets.
+    @param context Stream context initialized by #nestegg_init.
+    @param offset  Absolute offset in bytes.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_offset_seek(nestegg * context, uint64_t offset);
+
+/** Seek @a track to @a tstamp.  Stream seek will terminate at the earliest
+    key point in the stream at or before @a tstamp.  Other tracks in the
+    stream will output packets with unspecified but nearby timestamps.
+    @param context Stream context initialized by #nestegg_init.
+    @param track   Zero based track number.
+    @param tstamp  Absolute timestamp in nanoseconds.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_track_seek(nestegg * context, unsigned int track, uint64_t tstamp);
+
+/** Query the type specified by @a track.
+    @param context Stream context initialized by #nestegg_init.
+    @param track   Zero based track number.
+    @retval #NESTEGG_TRACK_VIDEO   Track type is video.
+    @retval #NESTEGG_TRACK_AUDIO   Track type is audio.
+    @retval #NESTEGG_TRACK_UNKNOWN Track type is unknown.
+    @retval -1 Error. */
+int nestegg_track_type(nestegg * context, unsigned int track);
+
+/** Query the codec ID specified by @a track.
+    @param context Stream context initialized by #nestegg_init.
+    @param track   Zero based track number.
+    @retval #NESTEGG_CODEC_VP8     Track codec is VP8.
+    @retval #NESTEGG_CODEC_VP9     Track codec is VP9.
+    @retval #NESTEGG_CODEC_AV1     Track codec is AV1.
+    @retval #NESTEGG_CODEC_VORBIS  Track codec is Vorbis.
+    @retval #NESTEGG_CODEC_OPUS    Track codec is Opus.
+    @retval #NESTEGG_CODEC_UNKNOWN Track codec is unknown.
+    @retval -1 Error. */
+int nestegg_track_codec_id(nestegg * context, unsigned int track);
+
+/** Query the number of codec initialization chunks for @a track.  Each
+    chunk of data should be passed to the codec initialization functions in
+    the order returned.
+    @param context Stream context initialized by #nestegg_init.
+    @param track   Zero based track number.
+    @param count   Storage for the queried chunk count.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_track_codec_data_count(nestegg * context, unsigned int track,
+                                   unsigned int * count);
+
+/** Get a pointer to chunk number @a item of codec initialization data for
+    @a track.
+    @param context Stream context initialized by #nestegg_init.
+    @param track   Zero based track number.
+    @param item    Zero based chunk item number.
+    @param data    Storage for the queried data pointer.
+                   The data is owned by the #nestegg context.
+    @param length  Storage for the queried data size.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_track_codec_data(nestegg * context, unsigned int track, unsigned int item,
+                             unsigned char ** data, size_t * length);
+
+/** Query the video parameters specified by @a track.
+    @param context Stream context initialized by #nestegg_init.
+    @param track   Zero based track number.
+    @param params  Storage for the queried video parameters.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_track_video_params(nestegg * context, unsigned int track,
+                               nestegg_video_params * params);
+
+/** Query the audio parameters specified by @a track.
+    @param context Stream context initialized by #nestegg_init.
+    @param track   Zero based track number.
+    @param params  Storage for the queried audio parameters.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_track_audio_params(nestegg * context, unsigned int track,
+                               nestegg_audio_params * params);
+
+/** Query the encoding status for @a track. If a track has multiple encodings
+    the first will be returned.
+    @param context Stream context initialized by #nestegg_init.
+    @param track   Zero based track number.
+    @retval #NESTEGG_ENCODING_COMPRESSION The track is compressed, but not encrypted.
+    @retval #NESTEGG_ENCODING_ENCRYPTION The track is encrypted and compressed.
+    @retval -1 Error. */
+int nestegg_track_encoding(nestegg * context, unsigned int track);
+
+/** Query the ContentEncKeyId for @a track. Will return an error if the track
+    in not encrypted, or is not recognized.
+    @param context                   Stream context initialized by #nestegg_init.
+    @param track                     Zero based track number.
+    @param content_enc_key_id        Storage for queried id. The content encryption key used.
+                                     Owned by nestegg and will be freed separately.
+    @param content_enc_key_id_length Length of the queried ContentEncKeyId in bytes.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_track_content_enc_key_id(nestegg * context, unsigned int track,
+                                     unsigned char const ** content_enc_key_id,
+                                     size_t * content_enc_key_id_length);
+
+/** Query the default frame duration for @a track.  For a video track, this
+    is typically the inverse of the video frame rate.
+    @param context  Stream context initialized by #nestegg_init.
+    @param track    Zero based track number.
+    @param duration Storage for the default duration in nanoseconds.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_track_default_duration(nestegg * context, unsigned int track,
+                                   uint64_t * duration);
+
+/** Reset parser state to the last valid state before nestegg_read_packet failed.
+    @param context Stream context initialized by #nestegg_init.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_read_reset(nestegg * context);
+
+/** Read a packet of media data.  A packet consists of one or more chunks of
+    data associated with a single track.  nestegg_read_packet should be
+    called in a loop while the return value is 1 to drive the stream parser
+    forward.  @see nestegg_free_packet
+    @param context Context returned by #nestegg_init.
+    @param packet  Storage for the returned nestegg_packet.
+    @retval  1 Additional packets may be read in subsequent calls.
+    @retval  0 End of stream.
+    @retval -1 Error. */
+int nestegg_read_packet(nestegg * context, nestegg_packet ** packet);
+
+/** Destroy a nestegg_packet and free associated memory.
+    @param packet #nestegg_packet to be freed. @see nestegg_read_packet */
+void nestegg_free_packet(nestegg_packet * packet);
+
+/** Query the keyframe status for a given packet.
+    @param packet Packet initialized by #nestegg_read_packet.
+    @retval #NESTEGG_PACKET_HAS_KEYFRAME_FALSE   Packet contains no keyframes.
+    @retval #NESTEGG_PACKET_HAS_KEYFRAME_TRUE    Packet contains keyframes.
+    @retval #NESTEGG_PACKET_HAS_KEYFRAME_UNKNOWN Unknown packet keyframe content.
+    @retval -1 Error. */
+int nestegg_packet_has_keyframe(nestegg_packet * packet);
+
+/** Query the track number of @a packet.
+    @param packet Packet initialized by #nestegg_read_packet.
+    @param track  Storage for the queried zero based track index.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_packet_track(nestegg_packet * packet, unsigned int * track);
+
+/** Query the timestamp in nanoseconds of @a packet.
+    @param packet Packet initialized by #nestegg_read_packet.
+    @param tstamp Storage for the queried timestamp in nanoseconds.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_packet_tstamp(nestegg_packet * packet, uint64_t * tstamp);
+
+/** Query the duration in nanoseconds of @a packet.
+    @param packet Packet initialized by #nestegg_read_packet.
+    @param duration Storage for the queried duration in nanoseconds.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_packet_duration(nestegg_packet * packet, uint64_t * duration);
+
+/** Query the number of data chunks contained in @a packet.
+    @param packet Packet initialized by #nestegg_read_packet.
+    @param count  Storage for the queried chunk count.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_packet_count(nestegg_packet * packet, unsigned int * count);
+
+/** Get a pointer to chunk number @a item of packet data.
+    @param packet  Packet initialized by #nestegg_read_packet.
+    @param item    Zero based chunk item number.
+    @param data    Storage for the queried data pointer.
+                   The data is owned by the #nestegg_packet packet.
+    @param length  Storage for the queried data size.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_packet_data(nestegg_packet * packet, unsigned int item,
+                        unsigned char ** data, size_t * length);
+
+/** Get a pointer to additional data with identifier @a id of additional packet
+    data. If @a id isn't present in the packet, returns -1.
+    @param packet  Packet initialized by #nestegg_read_packet.
+    @param id      Codec specific identifer. For VP8, use 1 to get a VP8 encoded
+                   frame containing an alpha channel in its Y plane.
+    @param data    Storage for the queried data pointer.
+                   The data is owned by the #nestegg_packet packet.
+    @param length  Storage for the queried data size.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_packet_additional_data(nestegg_packet * packet, unsigned int id,
+                                   unsigned char ** data, size_t * length);
+
+/** Returns discard_padding for given packet
+    @param packet  Packet initialized by #nestegg_read_packet.
+    @param discard_padding pointer to store discard padding in.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_packet_discard_padding(nestegg_packet * packet,
+                                   int64_t * discard_padding);
+
+/** Query if a packet is encrypted.
+    @param packet Packet initialized by #nestegg_read_packet.
+    @retval  #NESTEGG_PACKET_HAS_SIGNAL_BYTE_FALSE No signal byte, encryption
+             information not read from packet.
+    @retval  #NESTEGG_PACKET_HAS_SIGNAL_BYTE_UNENCRYPTED Encrypted bit not
+             set, encryption information not read from packet.
+    @retval  #NESTEGG_PACKET_HAS_SIGNAL_BYTE_ENCRYPTED Encrypted bit set,
+             encryption infomation read from packet.
+    @retval  #NESTEGG_PACKET_HAS_SIGNAL_BYTE_PARTITIONED Partitioned bit set,
+             encryption and parition information read from packet.
+    @retval -1 Error.*/
+int nestegg_packet_encryption(nestegg_packet * packet);
+
+/** Query the IV for an encrypted packet. Expects a packet from an encrypted
+    track, and will return error if given a packet that has no signal btye.
+    @param packet Packet initialized by #nestegg_read_packet.
+    @param iv     Storage for queried iv.
+    @param length Length of returned iv, may be 0.
+                  The data is owned by the #nestegg_packet packet.
+    @retval  0 Success.
+    @retval -1 Error.
+  */
+int nestegg_packet_iv(nestegg_packet * packet, unsigned char const ** iv,
+                      size_t * length);
+
+/** Query the packet for offsets.
+@param packet            Packet initialized by #nestegg_read_packet.
+@param partition_offsets Storage for queried offsets.
+@param num_offsets       Length of returned offsets, may be 0.
+The data is owned by the #nestegg_packet packet.
+@retval  0 Success.
+@retval -1 Error.
+*/
+int nestegg_packet_offsets(nestegg_packet * packet,
+                           uint32_t const ** partition_offsets,
+                           uint8_t * num_offsets);
+
+/** Returns reference_block given packet
+    @param packet          Packet initialized by #nestegg_read_packet.
+    @param reference_block pointer to store reference block in.
+    @retval  0 Success.
+    @retval -1 Error. */
+int nestegg_packet_reference_block(nestegg_packet * packet,
+                                   int64_t * reference_block);
+
+/** Query the presence of cues.
+    @param context  Stream context initialized by #nestegg_init.
+    @retval 0 The media has no cues.
+    @retval 1 The media has cues. */
+int nestegg_has_cues(nestegg * context);
+
+/** Try to determine if the buffer looks like the beginning of a WebM file.
+    @param buffer A buffer containing the beginning of a media file.
+    @param length The size of the buffer.
+    @retval 0 The file is not a WebM file.
+    @retval 1 The file is a WebM file. */
+int nestegg_sniff(unsigned char const * buffer, size_t length);
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* NESTEGG_671cac2a_365d_ed69_d7a3_4491d3538d79 */