Automatically resize the FIFO on writes, so that the data fits.

This automatic resizing happens up to a limit that can be modified with av_fifo_auto_grow_limit().

Definition at line 63 of file fifo.h.

Callback for writing or reading from a FIFO, passed to (and invoked from) the av_fifo_*_cb() functions.

It may be invoked multiple times from a single av_fifo_*_cb() call and may process less data than the maximum size indicated by nb_elems.

Parameters

opaque the opaque pointer provided to the av_fifo_*_cb() function

buf the buffer for reading or writing the data, depending on which av_fifo_*_cb function is called

nb_elems On entry contains the maximum number of elements that can be read from / written into buf. On success, the callback should update it to contain the number of elements actually written.

Returns

0 on success, a negative error code on failure (will be returned from the invoking av_fifo_*_cb() function)

Definition at line 56 of file fifo.h.

Allocate and initialize an AVFifo with a given element size.

Parameters

elems initial number of elements that can be stored in the FIFO

elem_size Size in bytes of a single element. Further operations on the returned FIFO will implicitly use this element size.

flags a combination of AV_FIFO_FLAG_*

Returns

newly-allocated AVFifo on success, a negative error code on failure

Definition at line 47 of file fifo.c.

Referenced by av1_decode_init(), av_audio_fifo_alloc(), av_container_fifo_alloc(), av_thread_message_queue_alloc(), config_input(), cuvid_decode_init(), d3d12va_encode_create_command_objects(), deshake_opencl_init(), dnn_detect_init(), dts2pts_init(), dv_init_mux(), ff_amf_encode_init(), ff_ccfifo_init(), ff_d3d12va_decode_init(), ff_d3d12va_encode_init(), ff_qsv_enc_init(), ff_qsvvpp_init(), ff_vaapi_encode_init(), ff_vulkan_encode_init(), fg_thread_init(), ifilter_alloc(), init(), input_init(), libvorbis_encode_init(), main(), mediacodec_init_async_state(), mpeg_mux_init(), nvenc_setup_surfaces(), oh_decode_init(), oh_encode_init(), packet_queue_init(), qsv_decode_init(), qsv_decode_preinit(), ring_init(), sch_add_mux_stream(), start_jack(), swf_write_header(), tq_alloc(), udp_open(), and vpx_init().

Returns

Element size for FIFO operations. This element size is set at FIFO allocation and remains constant during its lifetime

Definition at line 82 of file fifo.c.

Referenced by main().

Set the maximum size (in elements) to which the FIFO can be resized automatically.

Has no effect unless AV_FIFO_FLAG_AUTO_GROW is used.

Definition at line 77 of file fifo.c.

Returns

number of elements available for reading from the given FIFO.

Definition at line 87 of file fifo.c.

Referenced by activate(), amf_copy_buffer(), av_audio_fifo_realloc(), av_container_fifo_can_read(), av_container_fifo_drain(), av_fifo_can_write(), av_fifo_drain2(), av_thread_message_flush(), av_thread_message_queue_nb_elems(), cuvid_decode_packet(), cuvid_is_buffer_full(), dnn_detect_fill_side_data(), dnn_detect_uninit(), dts2pts_filter(), dv_assemble_frame(), ff_amf_encode_close(), ff_ccfifo_injectbytes(), ff_hw_base_encode_receive_packet(), ff_qsv_encode(), ff_qsvvpp_filter_frame(), fifo_peek_common(), flush_packet(), main(), mediacodec_get_input_index(), mpeg_mux_end(), mpeg_mux_write_packet(), mux_queue_packet(), output_packet(), output_ready(), process_callback(), qsv_decode(), qsv_decode_frame(), ring_size(), swf_write_video(), udp_read(), and uninit().

Returns

Number of elements that can be written into the given FIFO without growing it.

In other words, this number of elements or less is guaranteed to fit into the FIFO. More data may be written when the AV_FIFO_FLAG_AUTO_GROW flag was specified at FIFO creation, but this may involve memory allocation, which can fail.

Definition at line 94 of file fifo.c.

Referenced by activate(), av_audio_fifo_realloc(), dts2pts_filter(), dv_assemble_frame(), ff_hw_base_encode_receive_packet(), fifo_check_space(), libvorbis_encode_frame(), main(), mpeg_mux_write_packet(), mux_queue_packet(), process_callback(), ring_space(), ringbuf_float_at(), supply_new_packets(), swf_write_audio(), tq_send(), and udp_write().

Enlarge an AVFifo.

On success, the FIFO will be large enough to hold exactly inc + av_fifo_can_read() + av_fifo_can_write() elements. In case of failure, the old FIFO is kept unchanged.

Parameters

f AVFifo to resize

inc number of elements to allocate for, in addition to the current allocated size

Returns

a non-negative number on success, a negative error code on failure

Definition at line 99 of file fifo.c.

Referenced by av_audio_fifo_realloc(), fifo_check_space(), main(), mpeg_mux_write_packet(), and mux_queue_packet().

Write data into a FIFO.

In case nb_elems > av_fifo_can_write(f) and the AV_FIFO_FLAG_AUTO_GROW flag was not specified at FIFO creation, nothing is written and an error is returned.

Calling function is guaranteed to succeed if nb_elems <= av_fifo_can_write(f).

Parameters

f the FIFO buffer

buf Data to be written. nb_elems * av_fifo_elem_size(f) bytes will be read from buf on success.

nb_elems number of elements to write into FIFO

Returns

a non-negative number on success, a negative error code on failure

Definition at line 188 of file fifo.c.

Referenced by activate(), amf_submit_frame(), av1_receive_frame_internal(), av_audio_fifo_write(), av_container_fifo_write(), cuvid_handle_picture_display(), d3d12va_discard_command_allocator(), d3d12va_discard_helper_objects(), dnn_detect_parse_yolo_output(), dv_assemble_frame(), encode_frame(), ff_amf_receive_packet(), ff_ccfifo_extractbytes(), ff_hw_base_encode_receive_packet(), ff_nvenc_receive_packet(), ff_qsvvpp_filter_frame(), filter_frame(), frame_data_submit(), h264_queue_frame(), handle_input(), libvorbis_encode_frame(), main(), mpeg_mux_write_packet(), mux_queue_packet(), nvenc_alloc_surface(), nvenc_send_frame(), oh_decode_on_need_input(), oh_decode_on_output(), oh_encode_on_need_input(), oh_encode_on_output(), on_input_available(), on_output_available(), packet_queue_put_private(), process_callback(), qsv_decode(), qsv_decode_frame(), send_frame(), sub2video_frame(), supply_new_packets(), swf_write_audio(), timestamp_queue_enqueue(), tq_send(), and udp_write().

Write data from a user-provided callback into a FIFO.

Parameters

f the FIFO buffer

read_cb Callback supplying the data to the FIFO. May be called multiple times.

opaque opaque user data to be provided to read_cb

nb_elems Should point to the maximum number of elements that can be written. Will be updated to contain the number of elements actually written.

Returns

non-negative number on success, a negative error code on failure

Definition at line 193 of file fifo.c.

Referenced by main(), and ring_write().

Read data from a FIFO.

In case nb_elems > av_fifo_can_read(f), nothing is read and an error is returned.

Parameters

f the FIFO buffer

buf Buffer to store the data. nb_elems * av_fifo_elem_size(f) bytes will be written into buf on success.

nb_elems number of elements to read from FIFO

Returns

a non-negative number on success, a negative error code on failure

Definition at line 240 of file fifo.c.

Referenced by activate(), amf_copy_buffer(), audio_read_packet(), av1_decode_flush(), av1_decode_free(), av_audio_fifo_read(), av_container_fifo_drain(), av_container_fifo_free(), av_container_fifo_read(), configure_filtergraph(), cuvid_output_frame(), d3d12va_get_valid_command_allocator(), d3d12va_get_valid_helper_objects(), dnn_detect_fill_side_data(), dnn_detect_uninit(), dts2pts_filter(), dts2pts_flush(), export_metadata(), ff_amf_encode_close(), ff_amf_receive_packet(), ff_ccfifo_injectbytes(), ff_d3d12va_decode_uninit(), ff_d3d12va_encode_close(), ff_hw_base_encode_receive_packet(), ff_nvenc_receive_packet(), ff_qsv_enc_close(), ff_qsv_encode(), ff_qsvvpp_filter_frame(), fg_free(), fg_thread_uninit(), fifo_free(), filter_frame(), free_debug_matches(), free_pkt_fifo(), get_free_frame(), libvorbis_encode_frame(), main(), mediacodec_get_input_index(), mediacodec_get_output_index(), mux_task_start(), nvenc_send_frame(), oh_decode_receive_frame(), oh_encode_receive(), packet_queue_flush(), packet_queue_get(), process_callback(), qsv_clear_buffers(), qsv_decode(), qsv_decode_close_qsvcontext(), qsv_decode_frame(), receive_locked(), sch_free(), timestamp_queue_dequeue(), udp_read(), and uninit().

Feed data from a FIFO into a user-provided callback.

Parameters

f the FIFO buffer

write_cb Callback the data will be supplied to. May be called multiple times.

opaque opaque user data to be provided to write_cb

nb_elems Should point to the maximum number of elements that can be read. Will be updated to contain the total number of elements actually sent to the callback.

Returns

non-negative number on success, a negative error code on failure

Definition at line 247 of file fifo.c.

Referenced by av_thread_message_flush(), flush_packet(), main(), and swf_write_video().

Read data from a FIFO without modifying FIFO state.

Returns an error if an attempt is made to peek to nonexistent elements (i.e. if offset + nb_elems is larger than av_fifo_can_read(f)).

Parameters

f the FIFO buffer

buf Buffer to store the data. nb_elems * av_fifo_elem_size(f) bytes will be written into buf.

nb_elems number of elements to read from FIFO

offset number of initial elements to skip.

Returns

a non-negative number on success, a negative error code on failure

Definition at line 255 of file fifo.c.

Referenced by amf_copy_buffer(), av_audio_fifo_peek_at(), av_container_fifo_peek(), d3d12va_get_valid_command_allocator(), d3d12va_get_valid_helper_objects(), dnn_detect_fill_side_data(), drain_input_pts(), dv_inject_audio(), filter_frame(), frame_data_apply(), libplacebo_activate(), main(), mux_task_start(), ring_read(), ringbuf_float_at(), and timestamp_queue_peek().

Feed data from a FIFO into a user-provided callback.

Parameters

f the FIFO buffer

write_cb Callback the data will be supplied to. May be called multiple times.

opaque opaque user data to be provided to write_cb

nb_elems Should point to the maximum number of elements that can be read. Will be updated to contain the total number of elements actually sent to the callback.

offset number of initial elements to skip; offset + *nb_elems must not be larger than av_fifo_can_read(f).

Returns

a non-negative number on success, a negative error code on failure

Definition at line 260 of file fifo.c.

Referenced by main().

Discard the specified amount of data from an AVFifo.

Parameters

size number of elements to discard, MUST NOT be larger than av_fifo_can_read(f)

Definition at line 266 of file fifo.c.

Referenced by activate(), av_audio_fifo_drain(), av_fifo_read(), av_fifo_read_to_cb(), drain_input_pts(), dv_assemble_frame(), frame_data_apply(), ring_read(), and udp_read().

Definition at line 280 of file fifo.c.

Referenced by av_audio_fifo_reset(), ff_nvenc_encode_flush(), oh_decode_flush(), oh_encode_flush(), and ring_reset().

Free an AVFifo and reset pointer to NULL.

Parameters

f Pointer to an AVFifo to free. *f == NULL is allowed.

Definition at line 286 of file fifo.c.

Referenced by av1_decode_free(), av_audio_fifo_free(), av_container_fifo_free(), av_thread_message_queue_free(), cuvid_decode_end(), deshake_opencl_uninit(), dnn_detect_uninit(), dts2pts_close(), dv_deinit(), ff_amf_encode_close(), ff_ccfifo_uninit(), ff_d3d12va_decode_uninit(), ff_d3d12va_encode_close(), ff_hw_base_encode_close(), ff_nvenc_encode_close(), ff_qsv_enc_close(), ff_qsvvpp_close(), fg_free(), fg_thread_uninit(), fifo_free(), free_debug_matches(), free_pkt_fifo(), input_uninit(), libvorbis_encode_close(), main(), mediacodec_uninit_async_state(), mpeg_mux_deinit(), oh_decode_close(), oh_encode_close(), packet_queue_destroy(), qsv_decode_close(), qsv_decode_close_qsvcontext(), ring_destroy(), sch_free(), swf_deinit(), tq_free(), udp_close(), udp_open(), and uninit().