#define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
#define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
#define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
#define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
#define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
#define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */