libavcodec/codec_desc.h

   1 /*
   2  * Codec descriptors 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_DESC_H
  22 #define AVCODEC_CODEC_DESC_H
  23
  24 #include "libavutil/avutil.h"
  25
  26 #include "codec_id.h"
  27
  28 /**
  29  * @addtogroup lavc_core
  30  * @{
  31  */
  32
  33 /**
  34  * This struct describes the properties of a single codec described by an
  35  * AVCodecID.
  36  * @see avcodec_descriptor_get()
  37  */
  38 typedef struct AVCodecDescriptor {
  39     enum AVCodecID     id;
  40     enum AVMediaType type;
  41     /**
  42      * Name of the codec described by this descriptor. It is non-empty and
  43      * unique for each codec descriptor. It should contain alphanumeric
  44      * characters and '_' only.
  45      */
  46     const char      *name;
  47     /**
  48      * A more descriptive name for this codec. May be NULL.
  49      */
  50     const char *long_name;
  51     /**
  52      * Codec properties, a combination of AV_CODEC_PROP_* flags.
  53      */
  54     int             props;
  55     /**
  56      * MIME type(s) associated with the codec.
  57      * May be NULL; if not, a NULL-terminated array of MIME types.
  58      * The first item is always non-NULL and is the preferred MIME type.
  59      */
  60     const char *const *mime_types;
  61     /**
  62      * If non-NULL, an array of profiles recognized for this codec.
  63      * Terminated with AV_PROFILE_UNKNOWN.
  64      */
  65     const struct AVProfile *profiles;
  66 } AVCodecDescriptor;
  67
  68 /**
  69  * Codec uses only intra compression.
  70  * Video and audio codecs only.
  71  */
  72 #define AV_CODEC_PROP_INTRA_ONLY    (1 << 0)
  73 /**
  74  * Codec supports lossy compression. Audio and video codecs only.
  75  * @note a codec may support both lossy and lossless
  76  * compression modes
  77  */
  78 #define AV_CODEC_PROP_LOSSY         (1 << 1)
  79 /**
  80  * Codec supports lossless compression. Audio and video codecs only.
  81  */
  82 #define AV_CODEC_PROP_LOSSLESS      (1 << 2)
  83 /**
  84  * Codec supports frame reordering. That is, the coded order (the order in which
  85  * the encoded packets are output by the encoders / stored / input to the
  86  * decoders) may be different from the presentation order of the corresponding
  87  * frames.
  88  *
  89  * For codecs that do not have this property set, PTS and DTS should always be
  90  * equal.
  91  */
  92 #define AV_CODEC_PROP_REORDER       (1 << 3)
  93
  94 /**
  95  * Video codec supports separate coding of fields in interlaced frames.
  96  */
  97 #define AV_CODEC_PROP_FIELDS        (1 << 4)
  98
  99 /**
 100  * Subtitle codec is bitmap based
 101  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
 102  */
 103 #define AV_CODEC_PROP_BITMAP_SUB    (1 << 16)
 104 /**
 105  * Subtitle codec is text based.
 106  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
 107  */
 108 #define AV_CODEC_PROP_TEXT_SUB      (1 << 17)
 109
 110 /**
 111  * @return descriptor for given codec ID or NULL if no descriptor exists.
 112  */
 113 const AVCodecDescriptor *avcodec_descriptor_get(enum AVCodecID id);
 114
 115 /**
 116  * Iterate over all codec descriptors known to libavcodec.
 117  *
 118  * @param prev previous descriptor. NULL to get the first descriptor.
 119  *
 120  * @return next descriptor or NULL after the last descriptor
 121  */
 122 const AVCodecDescriptor *avcodec_descriptor_next(const AVCodecDescriptor *prev);
 123
 124 /**
 125  * @return codec descriptor with the given name or NULL if no such descriptor
 126  *         exists.
 127  */
 128 const AVCodecDescriptor *avcodec_descriptor_get_by_name(const char *name);
 129
 130 /**
 131  * @}
 132  */
 133
 134 #endif // AVCODEC_CODEC_DESC_H