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ffmpeg / libavformat / avio_internal.h @ d6bbe761

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/*
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVFORMAT_AVIO_INTERNAL_H
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#define AVFORMAT_AVIO_INTERNAL_H
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#include "avio.h"
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int ffio_init_context(AVIOContext *s,
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                  unsigned char *buffer,
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                  int buffer_size,
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                  int write_flag,
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                  void *opaque,
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                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
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/**
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 * Read size bytes from AVIOContext into buf.
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 * This reads at most 1 packet. If that is not enough fewer bytes will be
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 * returned.
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 * @return number of bytes read or AVERROR
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 */
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int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size);
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void ffio_fill(AVIOContext *s, int b, int count);
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static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
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{
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    avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
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}
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/**
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 * Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file.
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 * Used after probing to avoid seeking.
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 * Joins buf and s->buffer, taking any overlap into consideration.
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 * @note s->buffer must overlap with buf or they can't be joined and the function fails
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 *
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 * @param s The read-only AVIOContext to rewind
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 * @param buf The probe buffer containing the first buf_size bytes of the file
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 * @param buf_size The size of buf
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 * @return 0 in case of success, a negative value corresponding to an
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 * AVERROR code in case of failure
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 */
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int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size);
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uint64_t ffio_read_varlen(AVIOContext *bc);
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/** @warning must be called before any I/O */
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int ffio_set_buf_size(AVIOContext *s, int buf_size);
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/**
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 * Pause and resume playing - only meaningful if using a network streaming
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 * protocol (e.g. MMS).
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 * @param pause 1 for pause, 0 for resume
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 */
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int     ffio_read_pause(AVIOContext *h,    int pause);
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/**
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 * Seek to a given timestamp relative to some component stream.
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 * Only meaningful if using a network streaming protocol (e.g. MMS.).
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 * @param stream_index The stream index that the timestamp is relative to.
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 *        If stream_index is (-1) the timestamp should be in AV_TIME_BASE
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 *        units from the beginning of the presentation.
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 *        If a stream_index >= 0 is used and the protocol does not support
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 *        seeking based on component streams, the call will fail with ENOTSUP.
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 * @param timestamp timestamp in AVStream.time_base units
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 *        or if there is no stream specified then in AV_TIME_BASE units.
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 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
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 *        and AVSEEK_FLAG_ANY. The protocol may silently ignore
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 *        AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
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 *        fail with ENOTSUP if used and not supported.
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 * @return >= 0 on success
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 * @see AVInputFormat::read_seek
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 */
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int64_t ffio_read_seek (AVIOContext *h,    int stream_index,
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                        int64_t timestamp, int flags);
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void ffio_init_checksum(AVIOContext *s,
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                        unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
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                        unsigned long checksum);
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unsigned long ffio_get_checksum(AVIOContext *s);
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unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
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                                    unsigned int len);
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/**
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 * Open a write only packetized memory stream with a maximum packet
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 * size of 'max_packet_size'.  The stream is stored in a memory buffer
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 * with a big endian 4 byte header giving the packet size in bytes.
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 *
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 * @param s new IO context
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 * @param max_packet_size maximum packet size (must be > 0)
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 * @return zero if no error.
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 */
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int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
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/**
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 * Create and initialize a AVIOContext for accessing the
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 * resource referenced by the URLContext h.
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 * @note When the URLContext h has been opened in read+write mode, the
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 * AVIOContext can be used only for writing.
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 *
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 * @param s Used to return the pointer to the created AVIOContext.
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 * In case of failure the pointed to value is set to NULL.
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 * @return 0 in case of success, a negative value corresponding to an
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 * AVERROR code in case of failure
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 */
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int ffio_fdopen(AVIOContext **s, URLContext *h);
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#endif // AVFORMAT_AVIO_INTERNAL_H