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file | vpx_encoder.h |
| Describes the encoder algorithm interface to applications.
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#define | VPX_ENCODER_H |
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#define | VPX_TS_MAX_PERIODICITY 16 |
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#define | VPX_TS_MAX_LAYERS 5 |
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#define | MAX_PERIODICITY VPX_TS_MAX_PERIODICITY |
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#define | MAX_LAYERS VPX_TS_MAX_LAYERS |
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#define | VPX_ENCODER_ABI_VERSION |
| Current ABI version number.
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#define | VPX_CODEC_CAP_PSNR 0x10000 |
| Encoder capabilities bitfield. More...
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#define | VPX_CODEC_CAP_OUTPUT_PARTITION 0x20000 |
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#define | VPX_CODEC_USE_PSNR 0x10000 |
| Initialization-time Feature Enabling. More...
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#define | VPX_CODEC_USE_OUTPUT_PARTITION 0x20000 |
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#define | VPX_FRAME_IS_KEY 0x1 |
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#define | VPX_FRAME_IS_DROPPABLE 0x2 |
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#define | VPX_FRAME_IS_INVISIBLE 0x4 |
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#define | VPX_FRAME_IS_FRAGMENT 0x8 |
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#define | VPX_ERROR_RESILIENT_DEFAULT 0x1 |
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#define | VPX_ERROR_RESILIENT_PARTITIONS 0x2 |
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#define | VPX_EFLAG_FORCE_KF (1<<0) |
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#define | vpx_codec_enc_init(ctx, iface, cfg, flags) vpx_codec_enc_init_ver(ctx, iface, cfg, flags, VPX_ENCODER_ABI_VERSION) |
| Convenience macro for vpx_codec_enc_init_ver() More...
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#define | vpx_codec_enc_init_multi(ctx, iface, cfg, num_enc, flags, dsf) |
| Convenience macro for vpx_codec_enc_init_multi_ver() More...
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#define | VPX_DL_REALTIME (1) |
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#define | VPX_DL_GOOD_QUALITY (1000000) |
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#define | VPX_DL_BEST_QUALITY (0) |
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vpx_codec_err_t | vpx_codec_enc_init_ver (vpx_codec_ctx_t *ctx, vpx_codec_iface_t *iface, vpx_codec_enc_cfg_t *cfg, vpx_codec_flags_t flags, int ver) |
| Initialize an encoder instance. More...
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vpx_codec_err_t | vpx_codec_enc_init_multi_ver (vpx_codec_ctx_t *ctx, vpx_codec_iface_t *iface, vpx_codec_enc_cfg_t *cfg, int num_enc, vpx_codec_flags_t flags, vpx_rational_t *dsf, int ver) |
| Initialize multi-encoder instance. More...
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vpx_codec_err_t | vpx_codec_enc_config_default (vpx_codec_iface_t *iface, vpx_codec_enc_cfg_t *cfg, unsigned int usage) |
| Get a default configuration. More...
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vpx_codec_err_t | vpx_codec_enc_config_set (vpx_codec_ctx_t *ctx, const vpx_codec_enc_cfg_t *cfg) |
| Set or change configuration. More...
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vpx_fixed_buf_t * | vpx_codec_get_global_headers (vpx_codec_ctx_t *ctx) |
| Get global stream headers. More...
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vpx_codec_err_t | vpx_codec_encode (vpx_codec_ctx_t *ctx, const vpx_image_t *img, vpx_codec_pts_t pts, unsigned long duration, vpx_enc_frame_flags_t flags, unsigned long deadline) |
| Encode a frame. More...
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vpx_codec_err_t | vpx_codec_set_cx_data_buf (vpx_codec_ctx_t *ctx, const vpx_fixed_buf_t *buf, unsigned int pad_before, unsigned int pad_after) |
| Set compressed data output buffer. More...
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const vpx_codec_cx_pkt_t * | vpx_codec_get_cx_data (vpx_codec_ctx_t *ctx, vpx_codec_iter_t *iter) |
| Encoded data iterator. More...
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const vpx_image_t * | vpx_codec_get_preview_frame (vpx_codec_ctx_t *ctx) |
| Get Preview Frame. More...
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This abstraction allows applications using this encoder to easily support multiple video formats with minimal code duplication. This section describes the interface common to all encoders.
#define VPX_TS_MAX_PERIODICITY 16 |
Temporal Scalability: Maximum length of the sequence defining frame layer membership
#define VPX_TS_MAX_LAYERS 5 |
Temporal Scalability: Maximum number of coding layers
#define VPX_CODEC_CAP_PSNR 0x10000 |
Encoder capabilities bitfield.
Each encoder advertises the capabilities it supports as part of its vpx_codec_iface_t interface structure. Capabilities are extra interfaces or functionality, and are not required to be supported by an encoder.
The available flags are specified by VPX_CODEC_CAP_* defines.Can issue PSNR packets
#define VPX_CODEC_CAP_OUTPUT_PARTITION 0x20000 |
Can output one partition at a time. Each partition is returned in its own VPX_CODEC_CX_FRAME_PKT, with the FRAME_IS_FRAGMENT flag set for every partition but the last. In this mode all frames are always returned partition by partition.
#define VPX_CODEC_USE_PSNR 0x10000 |
Initialization-time Feature Enabling.
Certain codec features must be known at initialization time, to allow for proper memory allocation.
The available flags are specified by VPX_CODEC_USE_* defines.Calculate PSNR on each frame
#define VPX_CODEC_USE_OUTPUT_PARTITION 0x20000 |
Make the encoder output one partition at a time.
#define VPX_FRAME_IS_KEY 0x1 |
frame is the start of a GOP
#define VPX_FRAME_IS_DROPPABLE 0x2 |
frame can be dropped without affecting the stream (no future frame depends on this one)
#define VPX_FRAME_IS_INVISIBLE 0x4 |
frame should be decoded but will not be shown
#define VPX_FRAME_IS_FRAGMENT 0x8 |
this is a fragment of the encoded frame
#define VPX_ERROR_RESILIENT_DEFAULT 0x1 |
Improve resiliency against losses of whole frames
#define VPX_ERROR_RESILIENT_PARTITIONS 0x2 |
The frame partitions are independently decodable by the bool decoder, meaning that partitions can be decoded even though earlier partitions have been lost. Note that intra predicition is still done over the partition boundary.
#define VPX_EFLAG_FORCE_KF (1<<0) |
Force this frame to be a keyframe
#define vpx_codec_enc_init_multi |
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ctx, |
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iface, |
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cfg, |
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num_enc, |
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flags, |
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dsf |
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#define VPX_DL_REALTIME (1) |
deadline parameter analogous to VPx REALTIME mode.
#define VPX_DL_GOOD_QUALITY (1000000) |
deadline parameter analogous to VPx GOOD QUALITY mode.
#define VPX_DL_BEST_QUALITY (0) |
deadline parameter analogous to VPx BEST QUALITY mode.
Generic fixed size buffer structure.
This structure is able to hold a reference to any fixed size buffer.alias for struct vpx_fixed_buf
Time Stamp Type.
An integer, which when multiplied by the stream's time base, provides the absolute time of a sample.
Compressed Frame Flags.
This type represents a bitfield containing information about a compressed frame that may be useful to an application. The most significant 16 bits can be used by an algorithm to provide additional detail, for example to support frame types that are codec specific (MPEG-1 D-frames for example)
Error Resilient flags.
These flags define which error resilient features to enable in the encoder. The flags are specified through the vpx_codec_enc_cfg::g_error_resilient variable.
Encoder output packet.
This structure contains the different kinds of output data the encoder may produce while compressing a frame.alias for struct vpx_codec_cx_pkt
Rational Number.
This structure holds a fractional value.alias for struct vpx_rational
Encoded Frame Flags.
This type indicates a bitfield to be passed to vpx_codec_encode(), defining per-frame boolean values. By convention, bits common to all codecs will be named VPX_EFLAG_*, and bits specific to an algorithm will be named /algo/_eflag_*. The lower order 16 bits are reserved for common use.
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.alias for struct vpx_codec_enc_cfg
Encoder output packet variants.
This enumeration lists the different kinds of data packets that can be returned by calls to vpx_codec_get_cx_data(). Algorithms MAY extend this list to provide additional functionality.
Enumerator |
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VPX_CODEC_CX_FRAME_PKT |
Compressed video frame
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VPX_CODEC_STATS_PKT |
Two-pass statistics for this frame
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VPX_CODEC_PSNR_PKT |
PSNR statistics for this frame
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VPX_CODEC_CUSTOM_PKT |
Algorithm extensions
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Multi-pass Encoding Pass.
Enumerator |
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VPX_RC_ONE_PASS |
Single pass mode
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VPX_RC_FIRST_PASS |
First pass of multi-pass mode
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VPX_RC_LAST_PASS |
Final pass of multi-pass mode
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Rate control mode.
Enumerator |
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VPX_VBR |
Variable Bit Rate (VBR) mode
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VPX_CBR |
Constant Bit Rate (CBR) mode
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VPX_CQ |
Constant Quality (CQ) mode
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Keyframe placement mode.
This enumeration determines whether keyframes are placed automatically by the encoder or whether this behavior is disabled. Older releases of this SDK were implemented such that VPX_KF_FIXED meant keyframes were disabled. This name is confusing for this behavior, so the new symbols to be used are VPX_KF_AUTO and VPX_KF_DISABLED.
Enumerator |
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VPX_KF_FIXED |
deprecated, implies VPX_KF_DISABLED
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VPX_KF_AUTO |
Encoder determines optimal placement automatically
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VPX_KF_DISABLED |
Encoder does not place keyframes.
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Initialize an encoder instance.
Initializes a encoder context using the given interface. Applications
should call the vpx_codec_enc_init convenience macro instead of this
function directly, to ensure that the ABI version number parameter
is properly initialized.
If the library was configured with --disable-multithread, this call
is not thread safe and should be guarded with a lock if being used
in a multithreaded context.
In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
parameter), the storage pointed to by the cfg parameter must be
kept readable and stable until all memory maps have been set.
- Parameters
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[in] | ctx | Pointer to this instance's context. |
[in] | iface | Pointer to the algorithm interface to use. |
[in] | cfg | Configuration to use, if known. May be NULL. |
[in] | flags | Bitfield of VPX_CODEC_USE_* flags |
[in] | ver | ABI version number. Must be set to VPX_ENCODER_ABI_VERSION |
- Return values
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Initialize multi-encoder instance.
Initializes multi-encoder context using the given interface.
Applications should call the vpx_codec_enc_init_multi convenience macro
instead of this function directly, to ensure that the ABI version number
parameter is properly initialized.
In XMA mode (activated by setting VPX_CODEC_USE_XMA in the flags
parameter), the storage pointed to by the cfg parameter must be
kept readable and stable until all memory maps have been set.
- Parameters
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[in] | ctx | Pointer to this instance's context. |
[in] | iface | Pointer to the algorithm interface to use. |
[in] | cfg | Configuration to use, if known. May be NULL. |
[in] | num_enc | Total number of encoders. |
[in] | flags | Bitfield of VPX_CODEC_USE_* flags |
[in] | dsf | Pointer to down-sampling factors. |
[in] | ver | ABI version number. Must be set to VPX_ENCODER_ABI_VERSION |
- Return values
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Get a default configuration.
Initializes a encoder configuration structure with default values. Supports
the notion of "usages" so that an algorithm may offer different default
settings depending on the user's intended goal. This function \ref SHOULD
be called by all applications to initialize the configuration structure
before specializing the configuration with application specific values.
- Parameters
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[in] | iface | Pointer to the algorithm interface to use. |
[out] | cfg | Configuration buffer to populate |
[in] | usage | End usage. Set to 0 or use codec specific values. |
- Return values
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Set or change configuration.
Reconfigures an encoder instance according to the given configuration.
- Parameters
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[in] | ctx | Pointer to this instance's context |
[in] | cfg | Configuration buffer to use |
- Return values
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Get global stream headers.
Retrieves a stream level global header packet, if supported by the codec.
- Parameters
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[in] | ctx | Pointer to this instance's context |
- Return values
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NULL | Encoder does not support global header |
Non-NULL | Pointer to buffer containing global header packet |
Encode a frame.
Encodes a video frame at the given "presentation time." The presentation
time stamp (PTS) \ref MUST be strictly increasing.
The encoder supports the notion of a soft real-time deadline. Given a
non-zero value to the deadline parameter, the encoder will make a "best
effort" guarantee to return before the given time slice expires. It is
implicit that limiting the available time to encode will degrade the
output quality. The encoder can be given an unlimited time to produce the
best possible frame by specifying a deadline of '0'. This deadline
supercedes the VPx notion of "best quality, good quality, realtime".
Applications that wish to map these former settings to the new deadline
based system can use the symbols #VPX_DL_REALTIME, #VPX_DL_GOOD_QUALITY,
and #VPX_DL_BEST_QUALITY.
When the last frame has been passed to the encoder, this function should
continue to be called, with the img parameter set to NULL. This will
signal the end-of-stream condition to the encoder and allow it to encode
any held buffers. Encoding is complete when vpx_codec_encode() is called
and vpx_codec_get_cx_data() returns no data.
- Parameters
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[in] | ctx | Pointer to this instance's context |
[in] | img | Image data to encode, NULL to flush. |
[in] | pts | Presentation time stamp, in timebase units. |
[in] | duration | Duration to show frame, in timebase units. |
[in] | flags | Flags to use for encoding this frame. |
[in] | deadline | Time to spend encoding, in microseconds. (0=infinite) |
- Return values
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Set compressed data output buffer.
Sets the buffer that the codec should output the compressed data
into. This call effectively sets the buffer pointer returned in the
next VPX_CODEC_CX_FRAME_PKT packet. Subsequent packets will be
appended into this buffer. The buffer is preserved across frames,
so applications must periodically call this function after flushing
the accumulated compressed data to disk or to the network to reset
the pointer to the buffer's head.
`pad_before` bytes will be skipped before writing the compressed
data, and `pad_after` bytes will be appended to the packet. The size
of the packet will be the sum of the size of the actual compressed
data, pad_before, and pad_after. The padding bytes will be preserved
(not overwritten).
Note that calling this function does not guarantee that the returned
compressed data will be placed into the specified buffer. In the
event that the encoded data will not fit into the buffer provided,
the returned packet \ref MAY point to an internal buffer, as it would
if this call were never used. In this event, the output packet will
NOT have any padding, and the application must free space and copy it
to the proper place. This is of particular note in configurations
that may output multiple packets for a single encoded frame (e.g., lagged
encoding) or if the application does not reset the buffer periodically.
Applications may restore the default behavior of the codec providing
the compressed data buffer by calling this function with a NULL
buffer.
Applications \ref MUSTNOT call this function during iteration of
vpx_codec_get_cx_data().
- Parameters
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[in] | ctx | Pointer to this instance's context |
[in] | buf | Buffer to store compressed data into |
[in] | pad_before | Bytes to skip before writing compressed data |
[in] | pad_after | Bytes to skip after writing compressed data |
- Return values
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Encoded data iterator.
Iterates over a list of data packets to be passed from the encoder to the
application. The different kinds of packets available are enumerated in
#vpx_codec_cx_pkt_kind.
#VPX_CODEC_CX_FRAME_PKT packets should be passed to the application's
muxer. Multiple compressed frames may be in the list.
#VPX_CODEC_STATS_PKT packets should be appended to a global buffer.
The application \ref MUST silently ignore any packet kinds that it does
not recognize or support.
The data buffers returned from this function are only guaranteed to be
valid until the application makes another call to any vpx_codec_* function.
- Parameters
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[in] | ctx | Pointer to this instance's context |
[in,out] | iter | Iterator storage, initialized to NULL |
- Returns
- Returns a pointer to an output data packet (compressed frame data, two-pass statistics, etc.) or NULL to signal end-of-list.
Get Preview Frame.
Returns an image that can be used as a preview. Shows the image as it would
exist at the decompressor. The application \ref MUST NOT write into this
image buffer.
- Parameters
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[in] | ctx | Pointer to this instance's context |
- Returns
- Returns a pointer to a preview image, or NULL if no image is available.