| /* |
| * 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; |
| 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 */ |