FFmpeg
codec.h
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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 
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"
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 #if FF_API_FLAG_TRUNCATED
54 /**
55  * @deprecated Use parsers to always send proper frames.
56  */
57 #define AV_CODEC_CAP_TRUNCATED (1 << 3)
58 #endif
59 /**
60  * Encoder or decoder requires flushing with NULL input at the end in order to
61  * give the complete and correct output.
62  *
63  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
64  * with NULL data. The user can still send NULL data to the public encode
65  * or decode function, but libavcodec will not pass it along to the codec
66  * unless this flag is set.
67  *
68  * Decoders:
69  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
70  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
71  * returns frames.
72  *
73  * Encoders:
74  * The encoder needs to be fed with NULL data at the end of encoding until the
75  * encoder no longer returns data.
76  *
77  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
78  * flag also means that the encoder must set the pts and duration for
79  * each output packet. If this flag is not set, the pts and duration will
80  * be determined by libavcodec from the input frame.
81  */
82 #define AV_CODEC_CAP_DELAY (1 << 5)
83 /**
84  * Codec can be fed a final frame with a smaller size.
85  * This can be used to prevent truncation of the last audio samples.
86  */
87 #define AV_CODEC_CAP_SMALL_LAST_FRAME (1 << 6)
88 
89 /**
90  * Codec can output multiple frames per AVPacket
91  * Normally demuxers return one frame at a time, demuxers which do not do
92  * are connected to a parser to split what they return into proper frames.
93  * This flag is reserved to the very rare category of codecs which have a
94  * bitstream that cannot be split into frames without timeconsuming
95  * operations like full decoding. Demuxers carrying such bitstreams thus
96  * may return multiple frames in a packet. This has many disadvantages like
97  * prohibiting stream copy in many cases thus it should only be considered
98  * as a last resort.
99  */
100 #define AV_CODEC_CAP_SUBFRAMES (1 << 8)
101 /**
102  * Codec is experimental and is thus avoided in favor of non experimental
103  * encoders
104  */
105 #define AV_CODEC_CAP_EXPERIMENTAL (1 << 9)
106 /**
107  * Codec should fill in channel configuration and samplerate instead of container
108  */
109 #define AV_CODEC_CAP_CHANNEL_CONF (1 << 10)
110 /**
111  * Codec supports frame-level multithreading.
112  */
113 #define AV_CODEC_CAP_FRAME_THREADS (1 << 12)
114 /**
115  * Codec supports slice-based (or partition-based) multithreading.
116  */
117 #define AV_CODEC_CAP_SLICE_THREADS (1 << 13)
118 /**
119  * Codec supports changed parameters at any point.
120  */
121 #define AV_CODEC_CAP_PARAM_CHANGE (1 << 14)
122 /**
123  * Codec supports multithreading through a method other than slice- or
124  * frame-level multithreading. Typically this marks wrappers around
125  * multithreading-capable external libraries.
126  */
127 #define AV_CODEC_CAP_OTHER_THREADS (1 << 15)
128 #if FF_API_AUTO_THREADS
129 #define AV_CODEC_CAP_AUTO_THREADS AV_CODEC_CAP_OTHER_THREADS
130 #endif
131 /**
132  * Audio encoder supports receiving a different number of samples in each call.
133  */
134 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
135 /**
136  * Decoder is not a preferred choice for probing.
137  * This indicates that the decoder is not a good choice for probing.
138  * It could for example be an expensive to spin up hardware decoder,
139  * or it could simply not provide a lot of useful information about
140  * the stream.
141  * A decoder marked with this flag should only be used as last resort
142  * choice for probing.
143  */
144 #define AV_CODEC_CAP_AVOID_PROBING (1 << 17)
145 
146 #if FF_API_UNUSED_CODEC_CAPS
147 /**
148  * Deprecated and unused. Use AVCodecDescriptor.props instead
149  */
150 #define AV_CODEC_CAP_INTRA_ONLY 0x40000000
151 /**
152  * Deprecated and unused. Use AVCodecDescriptor.props instead
153  */
154 #define AV_CODEC_CAP_LOSSLESS 0x80000000
155 #endif
156 
157 /**
158  * Codec is backed by a hardware implementation. Typically used to
159  * identify a non-hwaccel hardware decoder. For information about hwaccels, use
160  * avcodec_get_hw_config() instead.
161  */
162 #define AV_CODEC_CAP_HARDWARE (1 << 18)
163 
164 /**
165  * Codec is potentially backed by a hardware implementation, but not
166  * necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the
167  * implementation provides some sort of internal fallback.
168  */
169 #define AV_CODEC_CAP_HYBRID (1 << 19)
170 
171 /**
172  * This codec takes the reordered_opaque field from input AVFrames
173  * and returns it in the corresponding field in AVCodecContext after
174  * encoding.
175  */
176 #define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE (1 << 20)
177 
178 /**
179  * This encoder can be flushed using avcodec_flush_buffers(). If this flag is
180  * not set, the encoder must be closed and reopened to ensure that no frames
181  * remain pending.
182  */
183 #define AV_CODEC_CAP_ENCODER_FLUSH (1 << 21)
184 
185 /**
186  * The encoder is able to output reconstructed frame data, i.e. raw frames that
187  * would be produced by decoding the encoded bitstream.
188  *
189  * Reconstructed frame output is enabled by the AV_CODEC_FLAG_RECON_FRAME flag.
190  */
191 #define AV_CODEC_CAP_ENCODER_RECON_FRAME (1 << 22)
192 
193 /**
194  * AVProfile.
195  */
196 typedef struct AVProfile {
197  int profile;
198  const char *name; ///< short name for the profile
199 } AVProfile;
200 
201 /**
202  * AVCodec.
203  */
204 typedef struct AVCodec {
205  /**
206  * Name of the codec implementation.
207  * The name is globally unique among encoders and among decoders (but an
208  * encoder and a decoder can share the same name).
209  * This is the primary way to find a codec from the user perspective.
210  */
211  const char *name;
212  /**
213  * Descriptive name for the codec, meant to be more human readable than name.
214  * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
215  */
216  const char *long_name;
218  enum AVCodecID id;
219  /**
220  * Codec capabilities.
221  * see AV_CODEC_CAP_*
222  */
224  uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
225  const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
226  const enum AVPixelFormat *pix_fmts; ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
227  const int *supported_samplerates; ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
228  const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
229 #if FF_API_OLD_CHANNEL_LAYOUT
230  /**
231  * @deprecated use ch_layouts instead
232  */
234  const uint64_t *channel_layouts; ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
235 #endif
236  const AVClass *priv_class; ///< AVClass for the private context
237  const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
238 
239  /**
240  * Group name of the codec implementation.
241  * This is a short symbolic name of the wrapper backing this codec. A
242  * wrapper uses some kind of external implementation for the codec, such
243  * as an external library, or a codec implementation provided by the OS or
244  * the hardware.
245  * If this field is NULL, this is a builtin, libavcodec native codec.
246  * If non-NULL, this will be the suffix in AVCodec.name in most cases
247  * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
248  */
249  const char *wrapper_name;
250 
251  /**
252  * Array of supported channel layouts, terminated with a zeroed layout.
253  */
255 } AVCodec;
256 
257 /**
258  * Iterate over all registered codecs.
259  *
260  * @param opaque a pointer where libavcodec will store the iteration state. Must
261  * point to NULL to start the iteration.
262  *
263  * @return the next registered codec or NULL when the iteration is
264  * finished
265  */
266 const AVCodec *av_codec_iterate(void **opaque);
267 
268 /**
269  * Find a registered decoder with a matching codec ID.
270  *
271  * @param id AVCodecID of the requested decoder
272  * @return A decoder if one was found, NULL otherwise.
273  */
274 const AVCodec *avcodec_find_decoder(enum AVCodecID id);
275 
276 /**
277  * Find a registered decoder with the specified name.
278  *
279  * @param name name of the requested decoder
280  * @return A decoder if one was found, NULL otherwise.
281  */
282 const AVCodec *avcodec_find_decoder_by_name(const char *name);
283 
284 /**
285  * Find a registered encoder with a matching codec ID.
286  *
287  * @param id AVCodecID of the requested encoder
288  * @return An encoder if one was found, NULL otherwise.
289  */
290 const AVCodec *avcodec_find_encoder(enum AVCodecID id);
291 
292 /**
293  * Find a registered encoder with the specified name.
294  *
295  * @param name name of the requested encoder
296  * @return An encoder if one was found, NULL otherwise.
297  */
298 const AVCodec *avcodec_find_encoder_by_name(const char *name);
299 /**
300  * @return a non-zero number if codec is an encoder, zero otherwise
301  */
302 int av_codec_is_encoder(const AVCodec *codec);
303 
304 /**
305  * @return a non-zero number if codec is a decoder, zero otherwise
306  */
307 int av_codec_is_decoder(const AVCodec *codec);
308 
309 /**
310  * Return a name for the specified profile, if available.
311  *
312  * @param codec the codec that is searched for the given profile
313  * @param profile the profile value for which a name is requested
314  * @return A name for the profile if found, NULL otherwise.
315  */
316 const char *av_get_profile_name(const AVCodec *codec, int profile);
317 
318 enum {
319  /**
320  * The codec supports this format via the hw_device_ctx interface.
321  *
322  * When selecting this format, AVCodecContext.hw_device_ctx should
323  * have been set to a device of the specified type before calling
324  * avcodec_open2().
325  */
327  /**
328  * The codec supports this format via the hw_frames_ctx interface.
329  *
330  * When selecting this format for a decoder,
331  * AVCodecContext.hw_frames_ctx should be set to a suitable frames
332  * context inside the get_format() callback. The frames context
333  * must have been created on a device of the specified type.
334  *
335  * When selecting this format for an encoder,
336  * AVCodecContext.hw_frames_ctx should be set to the context which
337  * will be used for the input frames before calling avcodec_open2().
338  */
340  /**
341  * The codec supports this format by some internal method.
342  *
343  * This format can be selected without any additional configuration -
344  * no device or frames context is required.
345  */
347  /**
348  * The codec supports this format by some ad-hoc method.
349  *
350  * Additional settings and/or function calls are required. See the
351  * codec-specific documentation for details. (Methods requiring
352  * this sort of configuration are deprecated and others should be
353  * used in preference.)
354  */
356 };
357 
358 typedef struct AVCodecHWConfig {
359  /**
360  * For decoders, a hardware pixel format which that decoder may be
361  * able to decode to if suitable hardware is available.
362  *
363  * For encoders, a pixel format which the encoder may be able to
364  * accept. If set to AV_PIX_FMT_NONE, this applies to all pixel
365  * formats supported by the codec.
366  */
368  /**
369  * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
370  * setup methods which can be used with this configuration.
371  */
372  int methods;
373  /**
374  * The device type associated with the configuration.
375  *
376  * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
377  * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
378  */
381 
382 /**
383  * Retrieve supported hardware configurations for a codec.
384  *
385  * Values of index from zero to some maximum return the indexed configuration
386  * descriptor; all other values return NULL. If the codec does not support
387  * any hardware configurations then it will always return NULL.
388  */
389 const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);
390 
391 /**
392  * @}
393  */
394 
395 #endif /* AVCODEC_CODEC_H */
AVCodec::ch_layouts
const AVChannelLayout * ch_layouts
Array of supported channel layouts, terminated with a zeroed layout.
Definition: codec.h:254
AVCodec
AVCodec.
Definition: codec.h:204
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
name
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option name
Definition: writing_filters.txt:88
AVCodec::long_name
const char * long_name
Descriptive name for the codec, meant to be more human readable than name.
Definition: codec.h:216
AVCodecHWConfig::methods
int methods
Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible setup methods which can be used...
Definition: codec.h:372
AVCodec::priv_class
const AVClass * priv_class
AVClass for the private context.
Definition: codec.h:236
AVProfile::name
const char * name
short name for the profile
Definition: codec.h:198
AV_CODEC_HW_CONFIG_METHOD_INTERNAL
@ AV_CODEC_HW_CONFIG_METHOD_INTERNAL
The codec supports this format by some internal method.
Definition: codec.h:346
rational.h
AVCodec::pix_fmts
enum AVPixelFormat * pix_fmts
array of supported pixel formats, or NULL if unknown, array is terminated by -1
Definition: codec.h:226
AVCodec::wrapper_name
const char * wrapper_name
Group name of the codec implementation.
Definition: codec.h:249
avcodec_find_encoder
const AVCodec * avcodec_find_encoder(enum AVCodecID id)
Find a registered encoder with a matching codec ID.
Definition: allcodecs.c:934
AVCodec::capabilities
int capabilities
Codec capabilities.
Definition: codec.h:223
version_major.h
AVProfile
AVProfile.
Definition: codec.h:196
AVCodec::max_lowres
uint8_t max_lowres
maximum value for lowres supported by the decoder
Definition: codec.h:224
AVCodec::sample_fmts
enum AVSampleFormat * sample_fmts
array of supported sample formats, or NULL if unknown, array is terminated by -1
Definition: codec.h:228
samplefmt.h
AVCodec::supported_samplerates
const int * supported_samplerates
array of supported audio samplerates, or NULL if unknown, array is terminated by 0
Definition: codec.h:227
codec_id.h
AVCodec::supported_framerates
const AVRational * supported_framerates
array of supported framerates, or NULL if any, array is terminated by {0,0}
Definition: codec.h:225
AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX
@ AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX
The codec supports this format via the hw_frames_ctx interface.
Definition: codec.h:339
AVHWDeviceType
AVHWDeviceType
Definition: hwcontext.h:27
AVCodecHWConfig::pix_fmt
enum AVPixelFormat pix_fmt
For decoders, a hardware pixel format which that decoder may be able to decode to if suitable hardwar...
Definition: codec.h:367
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
avcodec_find_decoder_by_name
const AVCodec * avcodec_find_decoder_by_name(const char *name)
Find a registered decoder with the specified name.
Definition: allcodecs.c:967
AVCodec::type
enum AVMediaType type
Definition: codec.h:217
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVCodec::profiles
const AVProfile * profiles
array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
Definition: codec.h:237
AVProfile::profile
int profile
Definition: codec.h:197
index
int index
Definition: gxfenc.c:89
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:47
avcodec_find_decoder
const AVCodec * avcodec_find_decoder(enum AVCodecID id)
Find a registered decoder with a matching codec ID.
Definition: allcodecs.c:939
av_codec_is_decoder
int av_codec_is_decoder(const AVCodec *codec)
Definition: utils.c:82
AVMediaType
AVMediaType
Definition: avutil.h:199
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:290
attribute_deprecated
#define attribute_deprecated
Definition: attributes.h:104
AVCodec::id
enum AVCodecID id
Definition: codec.h:218
av_codec_is_encoder
int av_codec_is_encoder(const AVCodec *codec)
Definition: utils.c:74
log.h
av_get_profile_name
const char * av_get_profile_name(const AVCodec *codec, int profile)
Return a name for the specified profile, if available.
Definition: utils.c:467
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
profile
int profile
Definition: mxfenc.c:2005
av_codec_iterate
const AVCodec * av_codec_iterate(void **opaque)
Iterate over all registered codecs.
Definition: allcodecs.c:890
pixfmt.h
AV_CODEC_HW_CONFIG_METHOD_AD_HOC
@ AV_CODEC_HW_CONFIG_METHOD_AD_HOC
The codec supports this format by some ad-hoc method.
Definition: codec.h:355
avcodec_get_hw_config
const AVCodecHWConfig * avcodec_get_hw_config(const AVCodec *codec, int index)
Retrieve supported hardware configurations for a codec.
Definition: utils.c:879
avutil.h
channel_layouts
static const uint16_t channel_layouts[7]
Definition: dca_lbr.c:111
hwcontext.h
AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX
@ AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX
The codec supports this format via the hw_device_ctx interface.
Definition: codec.h:326
AVCodecHWConfig
Definition: codec.h:358
AVCodecHWConfig::device_type
enum AVHWDeviceType device_type
The device type associated with the configuration.
Definition: codec.h:379
avcodec_find_encoder_by_name
const AVCodec * avcodec_find_encoder_by_name(const char *name)
Find a registered encoder with the specified name.
Definition: allcodecs.c:962