libavcodec/codec.h

   1 /*
   2  * AVCodec public API
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef AVCODEC_CODEC_H
  22 #define AVCODEC_CODEC_H
  23
  24 #include <stdint.h>
  25
  26 #include "libavutil/avutil.h"
  27 #include "libavutil/hwcontext.h"
  28 #include "libavutil/log.h"
  29 #include "libavutil/pixfmt.h"
  30 #include "libavutil/rational.h"
  31 #include "libavutil/samplefmt.h"
  32
  33 #include "libavcodec/codec_id.h"
  34 #include "libavcodec/version_major.h"
  35
  36 /**
  37  * @addtogroup lavc_core
  38  * @{
  39  */
  40
  41 /**
  42  * Decoder can use draw_horiz_band callback.
  43  */
  44 #define AV_CODEC_CAP_DRAW_HORIZ_BAND     (1 <<  0)
  45 /**
  46  * Codec uses get_buffer() or get_encode_buffer() for allocating buffers and
  47  * supports custom allocators.
  48  * If not set, it might not use get_buffer() or get_encode_buffer() at all, or
  49  * use operations that assume the buffer was allocated by
  50  * avcodec_default_get_buffer2 or avcodec_default_get_encode_buffer.
  51  */
  52 #define AV_CODEC_CAP_DR1                 (1 <<  1)
  53 /**
  54  * Encoder or decoder requires flushing with NULL input at the end in order to
  55  * give the complete and correct output.
  56  *
  57  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
  58  *       with NULL data. The user can still send NULL data to the public encode
  59  *       or decode function, but libavcodec will not pass it along to the codec
  60  *       unless this flag is set.
  61  *
  62  * Decoders:
  63  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
  64  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
  65  * returns frames.
  66  *
  67  * Encoders:
  68  * The encoder needs to be fed with NULL data at the end of encoding until the
  69  * encoder no longer returns data.
  70  *
  71  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
  72  *       flag also means that the encoder must set the pts and duration for
  73  *       each output packet. If this flag is not set, the pts and duration will
  74  *       be determined by libavcodec from the input frame.
  75  */
  76 #define AV_CODEC_CAP_DELAY               (1 <<  5)
  77 /**
  78  * Codec can be fed a final frame with a smaller size.
  79  * This can be used to prevent truncation of the last audio samples.
  80  */
  81 #define AV_CODEC_CAP_SMALL_LAST_FRAME    (1 <<  6)
  82
  83 /**
  84  * Codec is experimental and is thus avoided in favor of non experimental
  85  * encoders
  86  */
  87 #define AV_CODEC_CAP_EXPERIMENTAL        (1 <<  9)
  88 /**
  89  * Codec should fill in channel configuration and samplerate instead of container
  90  */
  91 #define AV_CODEC_CAP_CHANNEL_CONF        (1 << 10)
  92 /**
  93  * Codec supports frame-level multithreading.
  94  */
  95 #define AV_CODEC_CAP_FRAME_THREADS       (1 << 12)
  96 /**
  97  * Codec supports slice-based (or partition-based) multithreading.
  98  */
  99 #define AV_CODEC_CAP_SLICE_THREADS       (1 << 13)
 100 /**
 101  * Codec supports changed parameters at any point.
 102  */
 103 #define AV_CODEC_CAP_PARAM_CHANGE        (1 << 14)
 104 /**
 105  * Codec supports multithreading through a method other than slice- or
 106  * frame-level multithreading. Typically this marks wrappers around
 107  * multithreading-capable external libraries.
 108  */
 109 #define AV_CODEC_CAP_OTHER_THREADS       (1 << 15)
 110 /**
 111  * Audio encoder supports receiving a different number of samples in each call.
 112  */
 113 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
 114 /**
 115  * Decoder is not a preferred choice for probing.
 116  * This indicates that the decoder is not a good choice for probing.
 117  * It could for example be an expensive to spin up hardware decoder,
 118  * or it could simply not provide a lot of useful information about
 119  * the stream.
 120  * A decoder marked with this flag should only be used as last resort
 121  * choice for probing.
 122  */
 123 #define AV_CODEC_CAP_AVOID_PROBING       (1 << 17)
 124
 125 /**
 126  * Codec is backed by a hardware implementation. Typically used to
 127  * identify a non-hwaccel hardware decoder. For information about hwaccels, use
 128  * avcodec_get_hw_config() instead.
 129  */
 130 #define AV_CODEC_CAP_HARDWARE            (1 << 18)
 131
 132 /**
 133  * Codec is potentially backed by a hardware implementation, but not
 134  * necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the
 135  * implementation provides some sort of internal fallback.
 136  */
 137 #define AV_CODEC_CAP_HYBRID              (1 << 19)
 138
 139 /**
 140  * This encoder can reorder user opaque values from input AVFrames and return
 141  * them with corresponding output packets.
 142  * @see AV_CODEC_FLAG_COPY_OPAQUE
 143  */
 144 #define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE (1 << 20)
 145
 146 /**
 147  * This encoder can be flushed using avcodec_flush_buffers(). If this flag is
 148  * not set, the encoder must be closed and reopened to ensure that no frames
 149  * remain pending.
 150  */
 151 #define AV_CODEC_CAP_ENCODER_FLUSH   (1 << 21)
 152
 153 /**
 154  * The encoder is able to output reconstructed frame data, i.e. raw frames that
 155  * would be produced by decoding the encoded bitstream.
 156  *
 157  * Reconstructed frame output is enabled by the AV_CODEC_FLAG_RECON_FRAME flag.
 158  */
 159 #define AV_CODEC_CAP_ENCODER_RECON_FRAME (1 << 22)
 160
 161 /**
 162  * AVProfile.
 163  */
 164 typedef struct AVProfile {
 165     int profile;
 166     const char *name; ///< short name for the profile
 167 } AVProfile;
 168
 169 /**
 170  * AVCodec.
 171  */
 172 typedef struct AVCodec {
 173     /**
 174      * Name of the codec implementation.
 175      * The name is globally unique among encoders and among decoders (but an
 176      * encoder and a decoder can share the same name).
 177      * This is the primary way to find a codec from the user perspective.
 178      */
 179     const char *name;
 180     /**
 181      * Descriptive name for the codec, meant to be more human readable than name.
 182      * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
 183      */
 184     const char *long_name;
 185     enum AVMediaType type;
 186     enum AVCodecID id;
 187     /**
 188      * Codec capabilities.
 189      * see AV_CODEC_CAP_*
 190      */
 191     int capabilities;
 192     uint8_t max_lowres;                     ///< maximum value for lowres supported by the decoder
 193
 194     /**
 195      * Deprecated codec capabilities.
 196      */
 197     attribute_deprecated
 198     const AVRational *supported_framerates; ///< @deprecated use avcodec_get_supported_config()
 199     attribute_deprecated
 200     const enum AVPixelFormat *pix_fmts;     ///< @deprecated use avcodec_get_supported_config()
 201     attribute_deprecated
 202     const int *supported_samplerates;       ///< @deprecated use avcodec_get_supported_config()
 203     attribute_deprecated
 204     const enum AVSampleFormat *sample_fmts; ///< @deprecated use avcodec_get_supported_config()
 205
 206     const AVClass *priv_class;              ///< AVClass for the private context
 207     const AVProfile *profiles;              ///< array of recognized profiles, or NULL if unknown, array is terminated by {AV_PROFILE_UNKNOWN}
 208
 209     /**
 210      * Group name of the codec implementation.
 211      * This is a short symbolic name of the wrapper backing this codec. A
 212      * wrapper uses some kind of external implementation for the codec, such
 213      * as an external library, or a codec implementation provided by the OS or
 214      * the hardware.
 215      * If this field is NULL, this is a builtin, libavcodec native codec.
 216      * If non-NULL, this will be the suffix in AVCodec.name in most cases
 217      * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
 218      */
 219     const char *wrapper_name;
 220
 221     /**
 222      * Array of supported channel layouts, terminated with a zeroed layout.
 223      * @deprecated use avcodec_get_supported_config()
 224      */
 225     attribute_deprecated
 226     const AVChannelLayout *ch_layouts;
 227 } AVCodec;
 228
 229 /**
 230  * Iterate over all registered codecs.
 231  *
 232  * @param opaque a pointer where libavcodec will store the iteration state. Must
 233  *               point to NULL to start the iteration.
 234  *
 235  * @return the next registered codec or NULL when the iteration is
 236  *         finished
 237  */
 238 const AVCodec *av_codec_iterate(void **opaque);
 239
 240 /**
 241  * Find a registered decoder with a matching codec ID.
 242  *
 243  * @param id AVCodecID of the requested decoder
 244  * @return A decoder if one was found, NULL otherwise.
 245  */
 246 const AVCodec *avcodec_find_decoder(enum AVCodecID id);
 247
 248 /**
 249  * Find a registered decoder with the specified name.
 250  *
 251  * @param name name of the requested decoder
 252  * @return A decoder if one was found, NULL otherwise.
 253  */
 254 const AVCodec *avcodec_find_decoder_by_name(const char *name);
 255
 256 /**
 257  * Find a registered encoder with a matching codec ID.
 258  *
 259  * @param id AVCodecID of the requested encoder
 260  * @return An encoder if one was found, NULL otherwise.
 261  */
 262 const AVCodec *avcodec_find_encoder(enum AVCodecID id);
 263
 264 /**
 265  * Find a registered encoder with the specified name.
 266  *
 267  * @param name name of the requested encoder
 268  * @return An encoder if one was found, NULL otherwise.
 269  */
 270 const AVCodec *avcodec_find_encoder_by_name(const char *name);
 271 /**
 272  * @return a non-zero number if codec is an encoder, zero otherwise
 273  */
 274 int av_codec_is_encoder(const AVCodec *codec);
 275
 276 /**
 277  * @return a non-zero number if codec is a decoder, zero otherwise
 278  */
 279 int av_codec_is_decoder(const AVCodec *codec);
 280
 281 /**
 282  * Return a name for the specified profile, if available.
 283  *
 284  * @param codec the codec that is searched for the given profile
 285  * @param profile the profile value for which a name is requested
 286  * @return A name for the profile if found, NULL otherwise.
 287  */
 288 const char *av_get_profile_name(const AVCodec *codec, int profile);
 289
 290 enum {
 291     /**
 292      * The codec supports this format via the hw_device_ctx interface.
 293      *
 294      * When selecting this format, AVCodecContext.hw_device_ctx should
 295      * have been set to a device of the specified type before calling
 296      * avcodec_open2().
 297      */
 298     AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX = 0x01,
 299     /**
 300      * The codec supports this format via the hw_frames_ctx interface.
 301      *
 302      * When selecting this format for a decoder,
 303      * AVCodecContext.hw_frames_ctx should be set to a suitable frames
 304      * context inside the get_format() callback.  The frames context
 305      * must have been created on a device of the specified type.
 306      *
 307      * When selecting this format for an encoder,
 308      * AVCodecContext.hw_frames_ctx should be set to the context which
 309      * will be used for the input frames before calling avcodec_open2().
 310      */
 311     AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX = 0x02,
 312     /**
 313      * The codec supports this format by some internal method.
 314      *
 315      * This format can be selected without any additional configuration -
 316      * no device or frames context is required.
 317      */
 318     AV_CODEC_HW_CONFIG_METHOD_INTERNAL      = 0x04,
 319     /**
 320      * The codec supports this format by some ad-hoc method.
 321      *
 322      * Additional settings and/or function calls are required.  See the
 323      * codec-specific documentation for details.  (Methods requiring
 324      * this sort of configuration are deprecated and others should be
 325      * used in preference.)
 326      */
 327     AV_CODEC_HW_CONFIG_METHOD_AD_HOC        = 0x08,
 328 };
 329
 330 typedef struct AVCodecHWConfig {
 331     /**
 332      * For decoders, a hardware pixel format which that decoder may be
 333      * able to decode to if suitable hardware is available.
 334      *
 335      * For encoders, a pixel format which the encoder may be able to
 336      * accept.  If set to AV_PIX_FMT_NONE, this applies to all pixel
 337      * formats supported by the codec.
 338      */
 339     enum AVPixelFormat pix_fmt;
 340     /**
 341      * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
 342      * setup methods which can be used with this configuration.
 343      */
 344     int methods;
 345     /**
 346      * The device type associated with the configuration.
 347      *
 348      * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
 349      * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
 350      */
 351     enum AVHWDeviceType device_type;
 352 } AVCodecHWConfig;
 353
 354 /**
 355  * Retrieve supported hardware configurations for a codec.
 356  *
 357  * Values of index from zero to some maximum return the indexed configuration
 358  * descriptor; all other values return NULL.  If the codec does not support
 359  * any hardware configurations then it will always return NULL.
 360  */
 361 const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);
 362
 363 /**
 364  * @}
 365  */
 366
 367 #endif /* AVCODEC_CODEC_H */