diff options
author | Anton Khirnov <anton@khirnov.net> | 2020-05-25 16:04:20 +0300 |
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committer | Anton Khirnov <anton@khirnov.net> | 2020-05-27 11:22:17 +0300 |
commit | ba6cada92eb7c3446bfb1d4525031d405a052516 (patch) | |
tree | 3e1657545fa0491765daf44d09c7582e72acde0c /libavcodec/codec.h | |
parent | 383c03ee0f9a3065347c81e9f9f96d233240250b (diff) |
avcodec.h: split AVCodec API into its own header
Diffstat (limited to 'libavcodec/codec.h')
-rw-r--r-- | libavcodec/codec.h | 462 |
1 files changed, 462 insertions, 0 deletions
diff --git a/libavcodec/codec.h b/libavcodec/codec.h new file mode 100644 index 0000000000..1fda619ee7 --- /dev/null +++ b/libavcodec/codec.h @@ -0,0 +1,462 @@ +/* + * AVCodec public API + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVCODEC_CODEC_H +#define AVCODEC_CODEC_H + +#include <stdint.h> + +#include "libavutil/avutil.h" +#include "libavutil/hwcontext.h" +#include "libavutil/log.h" +#include "libavutil/pixfmt.h" +#include "libavutil/rational.h" +#include "libavutil/samplefmt.h" + +#include "libavcodec/codec_id.h" +#include "libavcodec/version.h" + +/** + * @addtogroup lavc_core + * @{ + */ + +/** + * Decoder can use draw_horiz_band callback. + */ +#define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0) +/** + * Codec uses get_buffer() for allocating buffers and supports custom allocators. + * If not set, it might not use get_buffer() at all or use operations that + * assume the buffer was allocated by avcodec_default_get_buffer. + */ +#define AV_CODEC_CAP_DR1 (1 << 1) +#define AV_CODEC_CAP_TRUNCATED (1 << 3) +/** + * Encoder or decoder requires flushing with NULL input at the end in order to + * give the complete and correct output. + * + * NOTE: If this flag is not set, the codec is guaranteed to never be fed with + * with NULL data. The user can still send NULL data to the public encode + * or decode function, but libavcodec will not pass it along to the codec + * unless this flag is set. + * + * Decoders: + * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL, + * avpkt->size=0 at the end to get the delayed data until the decoder no longer + * returns frames. + * + * Encoders: + * The encoder needs to be fed with NULL data at the end of encoding until the + * encoder no longer returns data. + * + * NOTE: For encoders implementing the AVCodec.encode2() function, setting this + * flag also means that the encoder must set the pts and duration for + * each output packet. If this flag is not set, the pts and duration will + * be determined by libavcodec from the input frame. + */ +#define AV_CODEC_CAP_DELAY (1 << 5) +/** + * Codec can be fed a final frame with a smaller size. + * This can be used to prevent truncation of the last audio samples. + */ +#define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6) + +/** + * Codec can output multiple frames per AVPacket + * Normally demuxers return one frame at a time, demuxers which do not do + * are connected to a parser to split what they return into proper frames. + * This flag is reserved to the very rare category of codecs which have a + * bitstream that cannot be split into frames without timeconsuming + * operations like full decoding. Demuxers carrying such bitstreams thus + * may return multiple frames in a packet. This has many disadvantages like + * prohibiting stream copy in many cases thus it should only be considered + * as a last resort. + */ +#define AV_CODEC_CAP_SUBFRAMES (1 << 8) +/** + * Codec is experimental and is thus avoided in favor of non experimental + * encoders + */ +#define AV_CODEC_CAP_EXPERIMENTAL (1 << 9) +/** + * Codec should fill in channel configuration and samplerate instead of container + */ +#define AV_CODEC_CAP_CHANNEL_CONF (1 << 10) +/** + * Codec supports frame-level multithreading. + */ +#define AV_CODEC_CAP_FRAME_THREADS (1 << 12) +/** + * Codec supports slice-based (or partition-based) multithreading. + */ +#define AV_CODEC_CAP_SLICE_THREADS (1 << 13) +/** + * Codec supports changed parameters at any point. + */ +#define AV_CODEC_CAP_PARAM_CHANGE (1 << 14) +/** + * Codec supports avctx->thread_count == 0 (auto). + */ +#define AV_CODEC_CAP_AUTO_THREADS (1 << 15) +/** + * Audio encoder supports receiving a different number of samples in each call. + */ +#define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16) +/** + * Decoder is not a preferred choice for probing. + * This indicates that the decoder is not a good choice for probing. + * It could for example be an expensive to spin up hardware decoder, + * or it could simply not provide a lot of useful information about + * the stream. + * A decoder marked with this flag should only be used as last resort + * choice for probing. + */ +#define AV_CODEC_CAP_AVOID_PROBING (1 << 17) + +#if FF_API_UNUSED_CODEC_CAPS +/** + * Deprecated and unused. Use AVCodecDescriptor.props instead + */ +#define AV_CODEC_CAP_INTRA_ONLY 0x40000000 +/** + * Deprecated and unused. Use AVCodecDescriptor.props instead + */ +#define AV_CODEC_CAP_LOSSLESS 0x80000000 +#endif + +/** + * Codec is backed by a hardware implementation. Typically used to + * identify a non-hwaccel hardware decoder. For information about hwaccels, use + * avcodec_get_hw_config() instead. + */ +#define AV_CODEC_CAP_HARDWARE (1 << 18) + +/** + * Codec is potentially backed by a hardware implementation, but not + * necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the + * implementation provides some sort of internal fallback. + */ +#define AV_CODEC_CAP_HYBRID (1 << 19) + +/** + * This codec takes the reordered_opaque field from input AVFrames + * and returns it in the corresponding field in AVCodecContext after + * encoding. + */ +#define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE (1 << 20) + +/** + * This encoder can be flushed using avcodec_flush_buffers(). If this flag is + * not set, the encoder must be closed and reopened to ensure that no frames + * remain pending. + */ +#define AV_CODEC_CAP_ENCODER_FLUSH (1 << 21) + +/** + * AVProfile. + */ +typedef struct AVProfile { + int profile; + const char *name; ///< short name for the profile +} AVProfile; + +typedef struct AVCodecDefault AVCodecDefault; + +struct AVCodecContext; +struct AVSubtitle; +struct AVPacket; + +/** + * AVCodec. + */ +typedef struct AVCodec { + /** + * Name of the codec implementation. + * The name is globally unique among encoders and among decoders (but an + * encoder and a decoder can share the same name). + * This is the primary way to find a codec from the user perspective. + */ + const char *name; + /** + * Descriptive name for the codec, meant to be more human readable than name. + * You should use the NULL_IF_CONFIG_SMALL() macro to define it. + */ + const char *long_name; + enum AVMediaType type; + enum AVCodecID id; + /** + * Codec capabilities. + * see AV_CODEC_CAP_* + */ + int capabilities; + const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0} + const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1 + const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0 + const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1 + const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0 + uint8_t max_lowres; ///< maximum value for lowres supported by the decoder + const AVClass *priv_class; ///< AVClass for the private context + const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN} + + /** + * Group name of the codec implementation. + * This is a short symbolic name of the wrapper backing this codec. A + * wrapper uses some kind of external implementation for the codec, such + * as an external library, or a codec implementation provided by the OS or + * the hardware. + * If this field is NULL, this is a builtin, libavcodec native codec. + * If non-NULL, this will be the suffix in AVCodec.name in most cases + * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>"). + */ + const char *wrapper_name; + + /***************************************************************** + * No fields below this line are part of the public API. They + * may not be used outside of libavcodec and can be changed and + * removed at will. + * New public fields should be added right above. + ***************************************************************** + */ + int priv_data_size; + struct AVCodec *next; + /** + * @name Frame-level threading support functions + * @{ + */ + /** + * Copy necessary context variables from a previous thread context to the current one. + * If not defined, the next thread will start automatically; otherwise, the codec + * must call ff_thread_finish_setup(). + * + * dst and src will (rarely) point to the same context, in which case memcpy should be skipped. + */ + int (*update_thread_context)(struct AVCodecContext *dst, const struct AVCodecContext *src); + /** @} */ + + /** + * Private codec-specific defaults. + */ + const AVCodecDefault *defaults; + + /** + * Initialize codec static data, called from avcodec_register(). + * + * This is not intended for time consuming operations as it is + * run for every codec regardless of that codec being used. + */ + void (*init_static_data)(struct AVCodec *codec); + + int (*init)(struct AVCodecContext *); + int (*encode_sub)(struct AVCodecContext *, uint8_t *buf, int buf_size, + const struct AVSubtitle *sub); + /** + * Encode data to an AVPacket. + * + * @param avctx codec context + * @param avpkt output AVPacket (may contain a user-provided buffer) + * @param[in] frame AVFrame containing the raw data to be encoded + * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a + * non-empty packet was returned in avpkt. + * @return 0 on success, negative error code on failure + */ + int (*encode2)(struct AVCodecContext *avctx, struct AVPacket *avpkt, + const struct AVFrame *frame, int *got_packet_ptr); + int (*decode)(struct AVCodecContext *, void *outdata, int *outdata_size, struct AVPacket *avpkt); + int (*close)(struct AVCodecContext *); + /** + * Encode API with decoupled packet/frame dataflow. The API is the + * same as the avcodec_ prefixed APIs (avcodec_send_frame() etc.), except + * that: + * - never called if the codec is closed or the wrong type, + * - if AV_CODEC_CAP_DELAY is not set, drain frames are never sent, + * - only one drain frame is ever passed down, + */ + int (*send_frame)(struct AVCodecContext *avctx, const struct AVFrame *frame); + int (*receive_packet)(struct AVCodecContext *avctx, struct AVPacket *avpkt); + + /** + * Decode API with decoupled packet/frame dataflow. This function is called + * to get one output frame. It should call ff_decode_get_packet() to obtain + * input data. + */ + int (*receive_frame)(struct AVCodecContext *avctx, struct AVFrame *frame); + /** + * Flush buffers. + * Will be called when seeking + */ + void (*flush)(struct AVCodecContext *); + /** + * Internal codec capabilities. + * See FF_CODEC_CAP_* in internal.h + */ + int caps_internal; + + /** + * Decoding only, a comma-separated list of bitstream filters to apply to + * packets before decoding. + */ + const char *bsfs; + + /** + * Array of pointers to hardware configurations supported by the codec, + * or NULL if no hardware supported. The array is terminated by a NULL + * pointer. + * + * The user can only access this field via avcodec_get_hw_config(). + */ + const struct AVCodecHWConfigInternal **hw_configs; + + /** + * List of supported codec_tags, terminated by FF_CODEC_TAGS_END. + */ + const uint32_t *codec_tags; +} AVCodec; + +/** + * Iterate over all registered codecs. + * + * @param opaque a pointer where libavcodec will store the iteration state. Must + * point to NULL to start the iteration. + * + * @return the next registered codec or NULL when the iteration is + * finished + */ +const AVCodec *av_codec_iterate(void **opaque); + +/** + * Find a registered decoder with a matching codec ID. + * + * @param id AVCodecID of the requested decoder + * @return A decoder if one was found, NULL otherwise. + */ +AVCodec *avcodec_find_decoder(enum AVCodecID id); + +/** + * Find a registered decoder with the specified name. + * + * @param name name of the requested decoder + * @return A decoder if one was found, NULL otherwise. + */ +AVCodec *avcodec_find_decoder_by_name(const char *name); + +/** + * Find a registered encoder with a matching codec ID. + * + * @param id AVCodecID of the requested encoder + * @return An encoder if one was found, NULL otherwise. + */ +AVCodec *avcodec_find_encoder(enum AVCodecID id); + +/** + * Find a registered encoder with the specified name. + * + * @param name name of the requested encoder + * @return An encoder if one was found, NULL otherwise. + */ +AVCodec *avcodec_find_encoder_by_name(const char *name); +/** + * @return a non-zero number if codec is an encoder, zero otherwise + */ +int av_codec_is_encoder(const AVCodec *codec); + +/** + * @return a non-zero number if codec is a decoder, zero otherwise + */ +int av_codec_is_decoder(const AVCodec *codec); + +enum { + /** + * The codec supports this format via the hw_device_ctx interface. + * + * When selecting this format, AVCodecContext.hw_device_ctx should + * have been set to a device of the specified type before calling + * avcodec_open2(). + */ + AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX = 0x01, + /** + * The codec supports this format via the hw_frames_ctx interface. + * + * When selecting this format for a decoder, + * AVCodecContext.hw_frames_ctx should be set to a suitable frames + * context inside the get_format() callback. The frames context + * must have been created on a device of the specified type. + * + * When selecting this format for an encoder, + * AVCodecContext.hw_frames_ctx should be set to the context which + * will be used for the input frames before calling avcodec_open2(). + */ + AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX = 0x02, + /** + * The codec supports this format by some internal method. + * + * This format can be selected without any additional configuration - + * no device or frames context is required. + */ + AV_CODEC_HW_CONFIG_METHOD_INTERNAL = 0x04, + /** + * The codec supports this format by some ad-hoc method. + * + * Additional settings and/or function calls are required. See the + * codec-specific documentation for details. (Methods requiring + * this sort of configuration are deprecated and others should be + * used in preference.) + */ + AV_CODEC_HW_CONFIG_METHOD_AD_HOC = 0x08, +}; + +typedef struct AVCodecHWConfig { + /** + * For decoders, a hardware pixel format which that decoder may be + * able to decode to if suitable hardware is available. + * + * For encoders, a pixel format which the encoder may be able to + * accept. If set to AV_PIX_FMT_NONE, this applies to all pixel + * formats supported by the codec. + */ + enum AVPixelFormat pix_fmt; + /** + * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible + * setup methods which can be used with this configuration. + */ + int methods; + /** + * The device type associated with the configuration. + * + * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and + * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused. + */ + enum AVHWDeviceType device_type; +} AVCodecHWConfig; + +/** + * Retrieve supported hardware configurations for a codec. + * + * Values of index from zero to some maximum return the indexed configuration + * descriptor; all other values return NULL. If the codec does not support + * any hardware configurations then it will always return NULL. + */ +const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index); + +/** + * @} + */ + +#endif /* AVCODEC_CODEC_H */ |