codec.h 17 KB

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  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. #ifndef AVCODEC_CODEC_H
  21. #define AVCODEC_CODEC_H
  22. #include <stdint.h>
  23. #include "libavutil/avutil.h"
  24. #include "libavutil/hwcontext.h"
  25. #include "libavutil/log.h"
  26. #include "libavutil/pixfmt.h"
  27. #include "libavutil/rational.h"
  28. #include "libavutil/samplefmt.h"
  29. #include "libavcodec/codec_id.h"
  30. #include "libavcodec/version.h"
  31. /**
  32. * @addtogroup lavc_core
  33. * @{
  34. */
  35. /**
  36. * Decoder can use draw_horiz_band callback.
  37. */
  38. #define AV_CODEC_CAP_DRAW_HORIZ_BAND (1 << 0)
  39. /**
  40. * Codec uses get_buffer() or get_encode_buffer() for allocating buffers and
  41. * supports custom allocators.
  42. * If not set, it might not use get_buffer() or get_encode_buffer() at all, or
  43. * use operations that assume the buffer was allocated by
  44. * avcodec_default_get_buffer2 or avcodec_default_get_encode_buffer.
  45. */
  46. #define AV_CODEC_CAP_DR1 (1 << 1)
  47. #if FF_API_FLAG_TRUNCATED
  48. /**
  49. * @deprecated Use parsers to always send proper frames.
  50. */
  51. #define AV_CODEC_CAP_TRUNCATED (1 << 3)
  52. #endif
  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. * Codec can output multiple frames per AVPacket
  84. * Normally demuxers return one frame at a time, demuxers which do not do
  85. * are connected to a parser to split what they return into proper frames.
  86. * This flag is reserved to the very rare category of codecs which have a
  87. * bitstream that cannot be split into frames without timeconsuming
  88. * operations like full decoding. Demuxers carrying such bitstreams thus
  89. * may return multiple frames in a packet. This has many disadvantages like
  90. * prohibiting stream copy in many cases thus it should only be considered
  91. * as a last resort.
  92. */
  93. #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
  94. /**
  95. * Codec is experimental and is thus avoided in favor of non experimental
  96. * encoders
  97. */
  98. #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
  99. /**
  100. * Codec should fill in channel configuration and samplerate instead of container
  101. */
  102. #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
  103. /**
  104. * Codec supports frame-level multithreading.
  105. */
  106. #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
  107. /**
  108. * Codec supports slice-based (or partition-based) multithreading.
  109. */
  110. #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
  111. /**
  112. * Codec supports changed parameters at any point.
  113. */
  114. #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
  115. /**
  116. * Codec supports multithreading through a method other than slice- or
  117. * frame-level multithreading. Typically this marks wrappers around
  118. * multithreading-capable external libraries.
  119. */
  120. #define AV_CODEC_CAP_OTHER_THREADS (1 << 15)
  121. #if FF_API_AUTO_THREADS
  122. #define AV_CODEC_CAP_AUTO_THREADS AV_CODEC_CAP_OTHER_THREADS
  123. #endif
  124. /**
  125. * Audio encoder supports receiving a different number of samples in each call.
  126. */
  127. #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
  128. /**
  129. * Decoder is not a preferred choice for probing.
  130. * This indicates that the decoder is not a good choice for probing.
  131. * It could for example be an expensive to spin up hardware decoder,
  132. * or it could simply not provide a lot of useful information about
  133. * the stream.
  134. * A decoder marked with this flag should only be used as last resort
  135. * choice for probing.
  136. */
  137. #define AV_CODEC_CAP_AVOID_PROBING (1 << 17)
  138. #if FF_API_UNUSED_CODEC_CAPS
  139. /**
  140. * Deprecated and unused. Use AVCodecDescriptor.props instead
  141. */
  142. #define AV_CODEC_CAP_INTRA_ONLY 0x40000000
  143. /**
  144. * Deprecated and unused. Use AVCodecDescriptor.props instead
  145. */
  146. #define AV_CODEC_CAP_LOSSLESS 0x80000000
  147. #endif
  148. /**
  149. * Codec is backed by a hardware implementation. Typically used to
  150. * identify a non-hwaccel hardware decoder. For information about hwaccels, use
  151. * avcodec_get_hw_config() instead.
  152. */
  153. #define AV_CODEC_CAP_HARDWARE (1 << 18)
  154. /**
  155. * Codec is potentially backed by a hardware implementation, but not
  156. * necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the
  157. * implementation provides some sort of internal fallback.
  158. */
  159. #define AV_CODEC_CAP_HYBRID (1 << 19)
  160. /**
  161. * This codec takes the reordered_opaque field from input AVFrames
  162. * and returns it in the corresponding field in AVCodecContext after
  163. * encoding.
  164. */
  165. #define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE (1 << 20)
  166. /**
  167. * This encoder can be flushed using avcodec_flush_buffers(). If this flag is
  168. * not set, the encoder must be closed and reopened to ensure that no frames
  169. * remain pending.
  170. */
  171. #define AV_CODEC_CAP_ENCODER_FLUSH (1 << 21)
  172. /**
  173. * AVProfile.
  174. */
  175. typedef struct AVProfile {
  176. int profile;
  177. const char *name; ///< short name for the profile
  178. } AVProfile;
  179. typedef struct AVCodecDefault AVCodecDefault;
  180. struct AVCodecContext;
  181. struct AVSubtitle;
  182. struct AVPacket;
  183. /**
  184. * AVCodec.
  185. */
  186. typedef struct AVCodec {
  187. /**
  188. * Name of the codec implementation.
  189. * The name is globally unique among encoders and among decoders (but an
  190. * encoder and a decoder can share the same name).
  191. * This is the primary way to find a codec from the user perspective.
  192. */
  193. const char *name;
  194. /**
  195. * Descriptive name for the codec, meant to be more human readable than name.
  196. * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
  197. */
  198. const char *long_name;
  199. enum AVMediaType type;
  200. enum AVCodecID id;
  201. /**
  202. * Codec capabilities.
  203. * see AV_CODEC_CAP_*
  204. */
  205. int capabilities;
  206. uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
  207. const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
  208. const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
  209. const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
  210. const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
  211. const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
  212. const AVClass *priv_class; ///< AVClass for the private context
  213. const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
  214. /**
  215. * Group name of the codec implementation.
  216. * This is a short symbolic name of the wrapper backing this codec. A
  217. * wrapper uses some kind of external implementation for the codec, such
  218. * as an external library, or a codec implementation provided by the OS or
  219. * the hardware.
  220. * If this field is NULL, this is a builtin, libavcodec native codec.
  221. * If non-NULL, this will be the suffix in AVCodec.name in most cases
  222. * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
  223. */
  224. const char *wrapper_name;
  225. /*****************************************************************
  226. * No fields below this line are part of the public API. They
  227. * may not be used outside of libavcodec and can be changed and
  228. * removed at will.
  229. * New public fields should be added right above.
  230. *****************************************************************
  231. */
  232. /**
  233. * Internal codec capabilities.
  234. * See FF_CODEC_CAP_* in internal.h
  235. */
  236. int caps_internal;
  237. int priv_data_size;
  238. /**
  239. * @name Frame-level threading support functions
  240. * @{
  241. */
  242. /**
  243. * Copy necessary context variables from a previous thread context to the current one.
  244. * If not defined, the next thread will start automatically; otherwise, the codec
  245. * must call ff_thread_finish_setup().
  246. *
  247. * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
  248. */
  249. int (*update_thread_context)(struct AVCodecContext *dst, const struct AVCodecContext *src);
  250. /**
  251. * Copy variables back to the user-facing context
  252. */
  253. int (*update_thread_context_for_user)(struct AVCodecContext *dst, const struct AVCodecContext *src);
  254. /** @} */
  255. /**
  256. * Private codec-specific defaults.
  257. */
  258. const AVCodecDefault *defaults;
  259. /**
  260. * Initialize codec static data, called from av_codec_iterate().
  261. *
  262. * This is not intended for time consuming operations as it is
  263. * run for every codec regardless of that codec being used.
  264. */
  265. void (*init_static_data)(struct AVCodec *codec);
  266. int (*init)(struct AVCodecContext *);
  267. int (*encode_sub)(struct AVCodecContext *, uint8_t *buf, int buf_size,
  268. const struct AVSubtitle *sub);
  269. /**
  270. * Encode data to an AVPacket.
  271. *
  272. * @param avctx codec context
  273. * @param avpkt output AVPacket
  274. * @param[in] frame AVFrame containing the raw data to be encoded
  275. * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
  276. * non-empty packet was returned in avpkt.
  277. * @return 0 on success, negative error code on failure
  278. */
  279. int (*encode2)(struct AVCodecContext *avctx, struct AVPacket *avpkt,
  280. const struct AVFrame *frame, int *got_packet_ptr);
  281. /**
  282. * Decode picture or subtitle data.
  283. *
  284. * @param avctx codec context
  285. * @param outdata codec type dependent output struct
  286. * @param[out] got_frame_ptr decoder sets to 0 or 1 to indicate that a
  287. * non-empty frame or subtitle was returned in
  288. * outdata.
  289. * @param[in] avpkt AVPacket containing the data to be decoded
  290. * @return amount of bytes read from the packet on success, negative error
  291. * code on failure
  292. */
  293. int (*decode)(struct AVCodecContext *avctx, void *outdata,
  294. int *got_frame_ptr, struct AVPacket *avpkt);
  295. int (*close)(struct AVCodecContext *);
  296. /**
  297. * Encode API with decoupled frame/packet dataflow. This function is called
  298. * to get one output packet. It should call ff_encode_get_frame() to obtain
  299. * input data.
  300. */
  301. int (*receive_packet)(struct AVCodecContext *avctx, struct AVPacket *avpkt);
  302. /**
  303. * Decode API with decoupled packet/frame dataflow. This function is called
  304. * to get one output frame. It should call ff_decode_get_packet() to obtain
  305. * input data.
  306. */
  307. int (*receive_frame)(struct AVCodecContext *avctx, struct AVFrame *frame);
  308. /**
  309. * Flush buffers.
  310. * Will be called when seeking
  311. */
  312. void (*flush)(struct AVCodecContext *);
  313. /**
  314. * Decoding only, a comma-separated list of bitstream filters to apply to
  315. * packets before decoding.
  316. */
  317. const char *bsfs;
  318. /**
  319. * Array of pointers to hardware configurations supported by the codec,
  320. * or NULL if no hardware supported. The array is terminated by a NULL
  321. * pointer.
  322. *
  323. * The user can only access this field via avcodec_get_hw_config().
  324. */
  325. const struct AVCodecHWConfigInternal *const *hw_configs;
  326. /**
  327. * List of supported codec_tags, terminated by FF_CODEC_TAGS_END.
  328. */
  329. const uint32_t *codec_tags;
  330. } AVCodec;
  331. /**
  332. * Iterate over all registered codecs.
  333. *
  334. * @param opaque a pointer where libavcodec will store the iteration state. Must
  335. * point to NULL to start the iteration.
  336. *
  337. * @return the next registered codec or NULL when the iteration is
  338. * finished
  339. */
  340. const AVCodec *av_codec_iterate(void **opaque);
  341. /**
  342. * Find a registered decoder with a matching codec ID.
  343. *
  344. * @param id AVCodecID of the requested decoder
  345. * @return A decoder if one was found, NULL otherwise.
  346. */
  347. const AVCodec *avcodec_find_decoder(enum AVCodecID id);
  348. /**
  349. * Find a registered decoder with the specified name.
  350. *
  351. * @param name name of the requested decoder
  352. * @return A decoder if one was found, NULL otherwise.
  353. */
  354. const AVCodec *avcodec_find_decoder_by_name(const char *name);
  355. /**
  356. * Find a registered encoder with a matching codec ID.
  357. *
  358. * @param id AVCodecID of the requested encoder
  359. * @return An encoder if one was found, NULL otherwise.
  360. */
  361. const AVCodec *avcodec_find_encoder(enum AVCodecID id);
  362. /**
  363. * Find a registered encoder with the specified name.
  364. *
  365. * @param name name of the requested encoder
  366. * @return An encoder if one was found, NULL otherwise.
  367. */
  368. const AVCodec *avcodec_find_encoder_by_name(const char *name);
  369. /**
  370. * @return a non-zero number if codec is an encoder, zero otherwise
  371. */
  372. int av_codec_is_encoder(const AVCodec *codec);
  373. /**
  374. * @return a non-zero number if codec is a decoder, zero otherwise
  375. */
  376. int av_codec_is_decoder(const AVCodec *codec);
  377. /**
  378. * Return a name for the specified profile, if available.
  379. *
  380. * @param codec the codec that is searched for the given profile
  381. * @param profile the profile value for which a name is requested
  382. * @return A name for the profile if found, NULL otherwise.
  383. */
  384. const char *av_get_profile_name(const AVCodec *codec, int profile);
  385. enum {
  386. /**
  387. * The codec supports this format via the hw_device_ctx interface.
  388. *
  389. * When selecting this format, AVCodecContext.hw_device_ctx should
  390. * have been set to a device of the specified type before calling
  391. * avcodec_open2().
  392. */
  393. AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX = 0x01,
  394. /**
  395. * The codec supports this format via the hw_frames_ctx interface.
  396. *
  397. * When selecting this format for a decoder,
  398. * AVCodecContext.hw_frames_ctx should be set to a suitable frames
  399. * context inside the get_format() callback. The frames context
  400. * must have been created on a device of the specified type.
  401. *
  402. * When selecting this format for an encoder,
  403. * AVCodecContext.hw_frames_ctx should be set to the context which
  404. * will be used for the input frames before calling avcodec_open2().
  405. */
  406. AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX = 0x02,
  407. /**
  408. * The codec supports this format by some internal method.
  409. *
  410. * This format can be selected without any additional configuration -
  411. * no device or frames context is required.
  412. */
  413. AV_CODEC_HW_CONFIG_METHOD_INTERNAL = 0x04,
  414. /**
  415. * The codec supports this format by some ad-hoc method.
  416. *
  417. * Additional settings and/or function calls are required. See the
  418. * codec-specific documentation for details. (Methods requiring
  419. * this sort of configuration are deprecated and others should be
  420. * used in preference.)
  421. */
  422. AV_CODEC_HW_CONFIG_METHOD_AD_HOC = 0x08,
  423. };
  424. typedef struct AVCodecHWConfig {
  425. /**
  426. * For decoders, a hardware pixel format which that decoder may be
  427. * able to decode to if suitable hardware is available.
  428. *
  429. * For encoders, a pixel format which the encoder may be able to
  430. * accept. If set to AV_PIX_FMT_NONE, this applies to all pixel
  431. * formats supported by the codec.
  432. */
  433. enum AVPixelFormat pix_fmt;
  434. /**
  435. * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
  436. * setup methods which can be used with this configuration.
  437. */
  438. int methods;
  439. /**
  440. * The device type associated with the configuration.
  441. *
  442. * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
  443. * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
  444. */
  445. enum AVHWDeviceType device_type;
  446. } AVCodecHWConfig;
  447. /**
  448. * Retrieve supported hardware configurations for a codec.
  449. *
  450. * Values of index from zero to some maximum return the indexed configuration
  451. * descriptor; all other values return NULL. If the codec does not support
  452. * any hardware configurations then it will always return NULL.
  453. */
  454. const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);
  455. /**
  456. * @}
  457. */
  458. #endif /* AVCODEC_CODEC_H */