adding ffmpeg specific version

1 files changed, 123 insertions, 0 deletions

diff --git a/ffmpeg1/libavformat/seek.h b/ffmpeg1/libavformat/seek.h
new file mode 100644
index 0000000..b27cb42
--- /dev/null
+++ b/ffmpeg1/libavformat/seek.h
@@ -0,0 +1,123 @@
+/*
+ * seek utility functions for use within format handlers
+ *
+ * Copyright (c) 2009 Ivan Schreter
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVFORMAT_SEEK_H
+#define AVFORMAT_SEEK_H
+
+#include "avformat.h"
+
+/**
+ * structure to store parser state of one AVStream
+ */
+typedef struct AVParserStreamState {
+    // saved members of AVStream
+    AVCodecParserContext   *parser;
+    int64_t                 last_IP_pts;
+    int64_t                 cur_dts;
+    int64_t                 reference_dts;
+    int                     probe_packets;
+} AVParserStreamState;
+
+/**
+ * structure to store parser state of AVFormat
+ */
+typedef struct AVParserState {
+    int64_t         fpos;                   ///< file position at the time of call
+
+    // saved members of AVFormatContext
+    AVPacketList   *packet_buffer;          ///< packet buffer of original state
+    AVPacketList   *parse_queue;            ///< parse queue of original state
+    AVPacketList   *raw_packet_buffer;      ///< raw packet buffer of original state
+    int raw_packet_buffer_remaining_size;   ///< remaining space in raw_packet_buffer
+
+    // saved info for streams
+    int                  nb_streams;        ///< number of streams with stored state
+    AVParserStreamState *stream_states;     ///< states of individual streams (array)
+} AVParserState;
+
+/**
+ * Search for the sync point of all active streams.
+ *
+ * This routine is not supposed to be called directly by a user application,
+ * but by demuxers.
+ *
+ * A sync point is defined as a point in stream, such that, when decoding start
+ * from this point, the decoded output of all streams synchronizes closest
+ * to the given timestamp ts. This routine also takes timestamp limits into account.
+ * Thus, the output will synchronize no sooner than ts_min and no later than ts_max.
+ *
+ * @param stream_index stream index for time base reference of timestamps
+ * @param pos          approximate position where to start searching for key frames
+ * @param min_ts       minimum allowed timestamp (position, if AVSEEK_FLAG_BYTE set)
+ * @param ts           target timestamp (or position, if AVSEEK_FLAG_BYTE set in flags)
+ * @param max_ts       maximum allowed timestamp (position, if AVSEEK_FLAG_BYTE set)
+ * @param flags        if AVSEEK_FLAG_ANY is set, seek to any frame, otherwise only
+ *                     to a keyframe. If AVSEEK_FLAG_BYTE is set, search by
+ *                     position, not by timestamp.
+ * @return -1 if no such sync point could be found, otherwise stream position
+ *                     (stream is repositioned to this position)
+ */
+int64_t ff_gen_syncpoint_search(AVFormatContext *s,
+                                int stream_index,
+                                int64_t pos,
+                                int64_t min_ts,
+                                int64_t ts,
+                                int64_t max_ts,
+                                int flags);
+
+/**
+ * Store current parser state and file position.
+ *
+ * This function can be used by demuxers before a destructive seeking algorithm
+ * to store the parser state. Depending on the outcome of the seek, either the original
+ * state can be restored or the new state kept and the original state freed.
+ *
+ * @note As a side effect, the original parser state is reset, since structures
+ *       are relinked to the stored state instead of being deeply-copied (for
+ *       performance reasons and to keep the code simple).
+ *
+ * @param s context from which to save state
+ * @return parser state object or NULL if memory could not be allocated
+ */
+AVParserState *ff_store_parser_state(AVFormatContext *s);
+
+/**
+ * Restore previously saved parser state and file position.
+ *
+ * Saved state will be invalidated and freed by this call, since internal
+ * structures will be relinked back to the stored state instead of being
+ * deeply-copied.
+ *
+ * @param s     context to which to restore state (same as used for storing state)
+ * @param state state to restore
+ */
+void ff_restore_parser_state(AVFormatContext *s, AVParserState *state);
+
+/**
+ * Free previously saved parser state.
+ *
+ * @param s     context to which the state belongs (same as used for storing state)
+ * @param state state to free
+ */
+void ff_free_parser_state(AVFormatContext *s, AVParserState *state);
+
+#endif /* AVFORMAT_SEEK_H */