Type Alias libaom_sys::aom_codec_enc_cfg_t
source · pub type aom_codec_enc_cfg_t = aom_codec_enc_cfg;
Expand description
Encoder configuration structure
This structure contains the encoder settings that have common representations across all codecs. This doesn’t imply that all codecs support all features, however.
Aliased Type§
struct aom_codec_enc_cfg_t {Show 54 fields
pub g_usage: u32,
pub g_threads: u32,
pub g_profile: u32,
pub g_w: u32,
pub g_h: u32,
pub g_limit: u32,
pub g_forced_max_frame_width: u32,
pub g_forced_max_frame_height: u32,
pub g_bit_depth: u32,
pub g_input_bit_depth: u32,
pub g_timebase: aom_rational,
pub g_error_resilient: u32,
pub g_pass: u32,
pub g_lag_in_frames: u32,
pub rc_dropframe_thresh: u32,
pub rc_resize_mode: u32,
pub rc_resize_denominator: u32,
pub rc_resize_kf_denominator: u32,
pub rc_superres_mode: u32,
pub rc_superres_denominator: u32,
pub rc_superres_kf_denominator: u32,
pub rc_superres_qthresh: u32,
pub rc_superres_kf_qthresh: u32,
pub rc_end_usage: u32,
pub rc_twopass_stats_in: aom_fixed_buf,
pub rc_firstpass_mb_stats_in: aom_fixed_buf,
pub rc_target_bitrate: u32,
pub rc_min_quantizer: u32,
pub rc_max_quantizer: u32,
pub rc_undershoot_pct: u32,
pub rc_overshoot_pct: u32,
pub rc_buf_sz: u32,
pub rc_buf_initial_sz: u32,
pub rc_buf_optimal_sz: u32,
pub rc_2pass_vbr_bias_pct: u32,
pub rc_2pass_vbr_minsection_pct: u32,
pub rc_2pass_vbr_maxsection_pct: u32,
pub fwd_kf_enabled: i32,
pub kf_mode: u32,
pub kf_min_dist: u32,
pub kf_max_dist: u32,
pub sframe_dist: u32,
pub sframe_mode: u32,
pub large_scale_tile: u32,
pub monochrome: u32,
pub full_still_picture_hdr: u32,
pub save_as_annexb: u32,
pub tile_width_count: i32,
pub tile_height_count: i32,
pub tile_widths: [i32; 64],
pub tile_heights: [i32; 64],
pub use_fixed_qp_offsets: u32,
pub fixed_qp_offsets: [i32; 5],
pub encoder_cfg: cfg_options,
}
Fields§
§g_usage: u32
Algorithm specific “usage” value
Algorithms may define multiple values for usage, which may convey the intent of how the application intends to use the stream. If this value is non-zero, consult the documentation for the codec to determine its meaning.
g_threads: u32
Maximum number of threads to use
For multi-threaded implementations, use no more than this number of threads. The codec may use fewer threads than allowed. The value 0 is equivalent to the value 1.
g_profile: u32
profile of bitstream to use
g_w: u32
Width of the frame
This value identifies the presentation resolution of the frame, in pixels. Note that the frames passed as input to the encoder must have this resolution. Frames will be presented by the decoder in this resolution, independent of any spatial resampling the encoder may do.
g_h: u32
Height of the frame
This value identifies the presentation resolution of the frame, in pixels. Note that the frames passed as input to the encoder must have this resolution. Frames will be presented by the decoder in this resolution, independent of any spatial resampling the encoder may do.
g_limit: u32
Max number of frames to encode
If force video mode is off (the default) and g_limit is 1, the encoder will encode a still picture (still_picture is set to 1 in the sequence header OBU). If in addition full_still_picture_hdr is 0 (the default), the encoder will use a reduced header (reduced_still_picture_header is set to 1 in the sequence header OBU) for the still picture.
g_forced_max_frame_width: u32
Forced maximum width of the frame
If this value is non-zero then it is used to force the maximum frame width written in write_sequence_header().
g_forced_max_frame_height: u32
Forced maximum height of the frame
If this value is non-zero then it is used to force the maximum frame height written in write_sequence_header().
g_bit_depth: u32
Bit-depth of the codec
This value identifies the bit_depth of the codec, Only certain bit-depths are supported as identified in the aom_bit_depth_t enum.
g_input_bit_depth: u32
Bit-depth of the input frames
This value identifies the bit_depth of the input frames in bits. Note that the frames passed as input to the encoder must have this bit-depth.
g_timebase: aom_rational
Stream timebase units
Indicates the smallest interval of time, in seconds, used by the stream. For fixed frame rate material, or variable frame rate material where frames are timed at a multiple of a given clock (ex: video capture), the \ref RECOMMENDED method is to set the timebase to the reciprocal of the frame rate (ex: 1001/30000 for 29.970 Hz NTSC). This allows the pts to correspond to the frame number, which can be handy. For re-encoding video from containers with absolute time timestamps, the \ref RECOMMENDED method is to set the timebase to that of the parent container or multimedia framework (ex: 1/1000 for ms, as in FLV).
g_error_resilient: u32
Enable error resilient modes.
The error resilient bitfield indicates to the encoder which features it should enable to take measures for streaming over lossy or noisy links.
g_pass: u32
Multi-pass Encoding Mode
This value should be set to the current phase for multi-pass encoding. For single pass, set to #AOM_RC_ONE_PASS.
g_lag_in_frames: u32
Allow lagged encoding
If set, this value allows the encoder to consume a number of input frames before producing output frames. This allows the encoder to base decisions for the current frame on future frames. This does increase the latency of the encoding pipeline, so it is not appropriate in all situations (ex: realtime encoding).
Note that this is a maximum value – the encoder may produce frames sooner than the given limit. Set this value to 0 to disable this feature.
rc_dropframe_thresh: u32
Temporal resampling configuration, if supported by the codec.
Temporal resampling allows the codec to “drop” frames as a strategy to meet its target data rate. This can cause temporal discontinuities in the encoded video, which may appear as stuttering during playback. This trade-off is often acceptable, but for many applications is not. It can be disabled in these cases.
Note that not all codecs support this feature. All aom AVx codecs do. For other codecs, consult the documentation for that algorithm.
This threshold is described as a percentage of the target data buffer. When the data buffer falls below this percentage of fullness, a dropped frame is indicated. Set the threshold to zero (0) to disable this feature.
rc_resize_mode: u32
Mode for spatial resampling, if supported by the codec.
Spatial resampling allows the codec to compress a lower resolution version of the frame, which is then upscaled by the decoder to the correct presentation resolution. This increases visual quality at low data rates, at the expense of CPU time on the encoder/decoder.
rc_resize_denominator: u32
Frame resize denominator.
The denominator for resize to use, assuming 8 as the numerator.
Valid denominators are 8 - 16 for now.
rc_resize_kf_denominator: u32
Keyframe resize denominator.
The denominator for resize to use, assuming 8 as the numerator.
Valid denominators are 8 - 16 for now.
rc_superres_mode: u32
Frame super-resolution scaling mode.
Similar to spatial resampling, frame super-resolution integrates upscaling after the encode/decode process. Taking control of upscaling and using restoration filters should allow it to outperform normal resizing.
rc_superres_denominator: u32
Frame super-resolution denominator.
The denominator for superres to use. If fixed it will only change if the cumulative scale change over resizing and superres is greater than 1/2; this forces superres to reduce scaling.
Valid denominators are 8 to 16.
Used only by AOM_SUPERRES_FIXED.
rc_superres_kf_denominator: u32
Keyframe super-resolution denominator.
The denominator for superres to use. If fixed it will only change if the cumulative scale change over resizing and superres is greater than 1/2; this forces superres to reduce scaling.
Valid denominators are 8 - 16 for now.
rc_superres_qthresh: u32
Frame super-resolution q threshold.
The q level threshold after which superres is used. Valid values are 1 to 63.
Used only by AOM_SUPERRES_QTHRESH
rc_superres_kf_qthresh: u32
Keyframe super-resolution q threshold.
The q level threshold after which superres is used for key frames. Valid values are 1 to 63.
Used only by AOM_SUPERRES_QTHRESH
rc_end_usage: u32
Rate control algorithm to use.
Indicates whether the end usage of this stream is to be streamed over a bandwidth constrained link, indicating that Constant Bit Rate (CBR) mode should be used, or whether it will be played back on a high bandwidth link, as from a local disk, where higher variations in bitrate are acceptable.
rc_twopass_stats_in: aom_fixed_buf
Two-pass stats buffer.
A buffer containing all of the stats packets produced in the first pass, concatenated.
rc_firstpass_mb_stats_in: aom_fixed_buf
first pass mb stats buffer.
A buffer containing all of the first pass mb stats packets produced in the first pass, concatenated.
rc_target_bitrate: u32
Target data rate
Target bitrate to use for this stream, in kilobits per second.
rc_min_quantizer: u32
Minimum (Best Quality) Quantizer
The quantizer is the most direct control over the quality of the encoded image. The range of valid values for the quantizer is codec specific. Consult the documentation for the codec to determine the values to use. To determine the range programmatically, call aom_codec_enc_config_default() with a usage value of 0.
rc_max_quantizer: u32
Maximum (Worst Quality) Quantizer
The quantizer is the most direct control over the quality of the encoded image. The range of valid values for the quantizer is codec specific. Consult the documentation for the codec to determine the values to use. To determine the range programmatically, call aom_codec_enc_config_default() with a usage value of 0.
rc_undershoot_pct: u32
Rate control adaptation undershoot control
This value, controls the tolerance of the VBR algorithm to undershoot and is used as a trigger threshold for more aggressive adaptation of Q.
Valid values in the range 0-100.
rc_overshoot_pct: u32
Rate control adaptation overshoot control
This value, controls the tolerance of the VBR algorithm to overshoot and is used as a trigger threshold for more aggressive adaptation of Q.
Valid values in the range 0-100.
rc_buf_sz: u32
Decoder Buffer Size
This value indicates the amount of data that may be buffered by the decoding application. Note that this value is expressed in units of time (milliseconds). For example, a value of 5000 indicates that the client will buffer (at least) 5000ms worth of encoded data. Use the target bitrate (#rc_target_bitrate) to convert to bits/bytes, if necessary.
rc_buf_initial_sz: u32
Decoder Buffer Initial Size
This value indicates the amount of data that will be buffered by the decoding application prior to beginning playback. This value is expressed in units of time (milliseconds). Use the target bitrate (#rc_target_bitrate) to convert to bits/bytes, if necessary.
rc_buf_optimal_sz: u32
Decoder Buffer Optimal Size
This value indicates the amount of data that the encoder should try to maintain in the decoder’s buffer. This value is expressed in units of time (milliseconds). Use the target bitrate (#rc_target_bitrate) to convert to bits/bytes, if necessary.
rc_2pass_vbr_bias_pct: u32
Two-pass mode CBR/VBR bias
Bias, expressed on a scale of 0 to 100, for determining target size for the current frame. The value 0 indicates the optimal CBR mode value should be used. The value 100 indicates the optimal VBR mode value should be used. Values in between indicate which way the encoder should “lean.”
rc_2pass_vbr_minsection_pct: u32
Two-pass mode per-GOP minimum bitrate
This value, expressed as a percentage of the target bitrate, indicates the minimum bitrate to be used for a single GOP (aka “section”)
rc_2pass_vbr_maxsection_pct: u32
Two-pass mode per-GOP maximum bitrate
This value, expressed as a percentage of the target bitrate, indicates the maximum bitrate to be used for a single GOP (aka “section”)
fwd_kf_enabled: i32
Option to enable forward reference key frame
kf_mode: u32
Keyframe placement mode
This value indicates whether the encoder should place keyframes at a fixed interval, or determine the optimal placement automatically (as governed by the #kf_min_dist and #kf_max_dist parameters)
kf_min_dist: u32
Keyframe minimum interval
This value, expressed as a number of frames, prevents the encoder from placing a keyframe nearer than kf_min_dist to the previous keyframe. At least kf_min_dist frames non-keyframes will be coded before the next keyframe. Set kf_min_dist equal to kf_max_dist for a fixed interval.
kf_max_dist: u32
Keyframe maximum interval
This value, expressed as a number of frames, forces the encoder to code a keyframe if one has not been coded in the last kf_max_dist frames. A value of 0 implies all frames will be keyframes. Set kf_min_dist equal to kf_max_dist for a fixed interval.
sframe_dist: u32
sframe interval
This value, expressed as a number of frames, forces the encoder to code an S-Frame every sframe_dist frames.
sframe_mode: u32
sframe insertion mode
This value must be set to 1 or 2, and tells the encoder how to insert S-Frames. It will only have an effect if sframe_dist != 0.
If altref is enabled:
- if sframe_mode == 1, the considered frame will be made into an S-Frame only if it is an altref frame
- if sframe_mode == 2, the next altref frame will be made into an S-Frame.
Otherwise: the considered frame will be made into an S-Frame.
large_scale_tile: u32
Tile coding mode
This value indicates the tile coding mode. A value of 0 implies a normal non-large-scale tile coding. A value of 1 implies a large-scale tile coding.
monochrome: u32
Monochrome mode
If this is nonzero, the encoder will generate a monochrome stream with no chroma planes.
full_still_picture_hdr: u32
full_still_picture_hdr
If this is nonzero, the encoder will generate a full header (reduced_still_picture_header is set to 0 in the sequence header OBU) even for still picture encoding. If this is zero (the default), a reduced header (reduced_still_picture_header is set to 1 in the sequence header OBU) is used for still picture encoding. This flag has no effect when a regular video with more than a single frame is encoded.
save_as_annexb: u32
Bitstream syntax mode
This value indicates the bitstream syntax mode. A value of 0 indicates bitstream is saved as Section 5 bitstream. A value of 1 indicates the bitstream is saved in Annex-B format
tile_width_count: i32
Number of explicit tile widths specified
This value indicates the number of tile widths specified A value of 0 implies no tile widths are specified. Tile widths are given in the array tile_widths[]
tile_height_count: i32
Number of explicit tile heights specified
This value indicates the number of tile heights specified A value of 0 implies no tile heights are specified. Tile heights are given in the array tile_heights[]
tile_widths: [i32; 64]
Array of specified tile widths
This array specifies tile widths (and may be empty) The number of widths specified is given by tile_width_count
tile_heights: [i32; 64]
Array of specified tile heights
This array specifies tile heights (and may be empty) The number of heights specified is given by tile_height_count
use_fixed_qp_offsets: u32
Whether encoder should use fixed QP offsets.
If a value of 1 is provided, encoder will use fixed QP offsets for frames at different levels of the pyramid. If a value of 0 is provided, encoder will NOT use fixed QP offsets. Note: This option is only relevant for –end-usage=q.
fixed_qp_offsets: [i32; 5]
Deprecated and ignored. DO NOT USE.
TODO(aomedia:3269): Remove fixed_qp_offsets in libaom v4.0.0.
encoder_cfg: cfg_options
Options defined per config file