avio_internal.h 3.8 KB

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  1. /*
  2. *
  3. * This file is part of Libav.
  4. *
  5. * Libav is free software; you can redistribute it and/or
  6. * modify it under the terms of the GNU Lesser General Public
  7. * License as published by the Free Software Foundation; either
  8. * version 2.1 of the License, or (at your option) any later version.
  9. *
  10. * Libav is distributed in the hope that it will be useful,
  11. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13. * Lesser General Public License for more details.
  14. *
  15. * You should have received a copy of the GNU Lesser General Public
  16. * License along with Libav; if not, write to the Free Software
  17. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18. */
  19. #ifndef AVFORMAT_AVIO_INTERNAL_H
  20. #define AVFORMAT_AVIO_INTERNAL_H
  21. #include "avio.h"
  22. #include "url.h"
  23. #include "libavutil/log.h"
  24. extern const AVClass ffio_url_class;
  25. int ffio_init_context(AVIOContext *s,
  26. unsigned char *buffer,
  27. int buffer_size,
  28. int write_flag,
  29. void *opaque,
  30. int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
  31. int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
  32. int64_t (*seek)(void *opaque, int64_t offset, int whence));
  33. /**
  34. * Read size bytes from AVIOContext into buf.
  35. * This reads at most 1 packet. If that is not enough fewer bytes will be
  36. * returned.
  37. * @return number of bytes read or AVERROR
  38. */
  39. int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size);
  40. void ffio_fill(AVIOContext *s, int b, int count);
  41. static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
  42. {
  43. avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
  44. }
  45. /**
  46. * Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file.
  47. * Used after probing to avoid seeking.
  48. * Joins buf and s->buffer, taking any overlap into consideration.
  49. * @note s->buffer must overlap with buf or they can't be joined and the function fails
  50. *
  51. * @param s The read-only AVIOContext to rewind
  52. * @param buf The probe buffer containing the first buf_size bytes of the file
  53. * @param buf_size The size of buf
  54. * @return 0 in case of success, a negative value corresponding to an
  55. * AVERROR code in case of failure
  56. */
  57. int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size);
  58. uint64_t ffio_read_varlen(AVIOContext *bc);
  59. /** @warning must be called before any I/O */
  60. int ffio_set_buf_size(AVIOContext *s, int buf_size);
  61. void ffio_init_checksum(AVIOContext *s,
  62. unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
  63. unsigned long checksum);
  64. unsigned long ffio_get_checksum(AVIOContext *s);
  65. unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
  66. unsigned int len);
  67. /**
  68. * Open a write only packetized memory stream with a maximum packet
  69. * size of 'max_packet_size'. The stream is stored in a memory buffer
  70. * with a big endian 4 byte header giving the packet size in bytes.
  71. *
  72. * @param s new IO context
  73. * @param max_packet_size maximum packet size (must be > 0)
  74. * @return zero if no error.
  75. */
  76. int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
  77. /**
  78. * Create and initialize a AVIOContext for accessing the
  79. * resource referenced by the URLContext h.
  80. * @note When the URLContext h has been opened in read+write mode, the
  81. * AVIOContext can be used only for writing.
  82. *
  83. * @param s Used to return the pointer to the created AVIOContext.
  84. * In case of failure the pointed to value is set to NULL.
  85. * @return 0 in case of success, a negative value corresponding to an
  86. * AVERROR code in case of failure
  87. */
  88. int ffio_fdopen(AVIOContext **s, URLContext *h);
  89. #endif /* AVFORMAT_AVIO_INTERNAL_H */