lavc: move small misc definitions into a separate header

This will allow to avoid #including the entire avcodec.h in some places.

doc/APIchanges

@@ -14,6 +14,16 @@ libavutil:     2021-04-27
 
 API changes, most recent first:
 
+2021-xx-xx - xxxxxxxxxx - lavc 59.1.100 - avcodec.h defs.h
+  Add new installed header defs.h. The following definitions are moved
+  into it from avcodec.h:
+    - AVDiscard
+    - AVAudioServiceType
+    - AVPanScan
+    - AVCPBProperties and av_cpb_properties_alloc()
+    - AVProducerReferenceTime
+    - av_xiphlacing()
+
 2021-04-27 - cb3ac722f4 - lavc 59.0.100 - avcodec.h
   Constified AVCodecParserContext.parser.
 

libavcodec/Makefile

@@ -12,6 +12,7 @@ HEADERS = ac3_parser.h                                                  \
           codec_id.h                                                    \
           codec_par.h                                                   \
           d3d11va.h                                                     \
+          defs.h                                                        \
           dirac.h                                                       \
           dv_profile.h                                                  \
           dxva2.h                                                       \

libavcodec/avcodec.h

@@ -46,6 +46,7 @@
 #include "codec_desc.h"
 #include "codec_par.h"
 #include "codec_id.h"
+#include "defs.h"
 #include "packet.h"
 #include "version.h"
 
@@ -181,16 +182,6 @@
  * @{
  */
 
-/**
- * @ingroup lavc_decoding
- * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
- * This is mainly needed because some optimized bitstream readers read
- * 32 or 64 bit at once and could read over the end.<br>
- * Note: If the first 23 bits of the additional bytes are not 0, then damaged
- * MPEG bitstreams could cause overread and segfault.
- */
-#define AV_INPUT_BUFFER_PADDING_SIZE 64
-
 /**
  * @ingroup lavc_encoding
  * minimum encoding buffer size
@@ -198,34 +189,6 @@
  */
 #define AV_INPUT_BUFFER_MIN_SIZE 16384
 
-/**
- * @ingroup lavc_decoding
- */
-enum AVDiscard{
-    /* We leave some space between them for extensions (drop some
-     * keyframes for intra-only or drop just some bidir frames). */
-    AVDISCARD_NONE    =-16, ///< discard nothing
-    AVDISCARD_DEFAULT =  0, ///< discard useless packets like 0 size packets in avi
-    AVDISCARD_NONREF  =  8, ///< discard all non reference
-    AVDISCARD_BIDIR   = 16, ///< discard all bidirectional frames
-    AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
-    AVDISCARD_NONKEY  = 32, ///< discard all frames except keyframes
-    AVDISCARD_ALL     = 48, ///< discard all
-};
-
-enum AVAudioServiceType {
-    AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
-    AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
-    AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
-    AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
-    AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
-    AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
-    AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
-    AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
-    AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
-    AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
-};
-
 /**
  * @ingroup lavc_encoding
  */
@@ -393,86 +356,6 @@ typedef struct RcOverride{
  */
 #define AV_CODEC_EXPORT_DATA_FILM_GRAIN (1 << 3)
 
-/**
- * Pan Scan area.
- * This specifies the area which should be displayed.
- * Note there may be multiple such areas for one frame.
- */
-typedef struct AVPanScan {
-    /**
-     * id
-     * - encoding: Set by user.
-     * - decoding: Set by libavcodec.
-     */
-    int id;
-
-    /**
-     * width and height in 1/16 pel
-     * - encoding: Set by user.
-     * - decoding: Set by libavcodec.
-     */
-    int width;
-    int height;
-
-    /**
-     * position of the top left corner in 1/16 pel for up to 3 fields/frames
-     * - encoding: Set by user.
-     * - decoding: Set by libavcodec.
-     */
-    int16_t position[3][2];
-} AVPanScan;
-
-/**
- * This structure describes the bitrate properties of an encoded bitstream. It
- * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
- * parameters for H.264/HEVC.
- */
-typedef struct AVCPBProperties {
-    /**
-     * Maximum bitrate of the stream, in bits per second.
-     * Zero if unknown or unspecified.
-     */
-    int64_t max_bitrate;
-    /**
-     * Minimum bitrate of the stream, in bits per second.
-     * Zero if unknown or unspecified.
-     */
-    int64_t min_bitrate;
-    /**
-     * Average bitrate of the stream, in bits per second.
-     * Zero if unknown or unspecified.
-     */
-    int64_t avg_bitrate;
-
-    /**
-     * The size of the buffer to which the ratecontrol is applied, in bits.
-     * Zero if unknown or unspecified.
-     */
-    int64_t buffer_size;
-
-    /**
-     * The delay between the time the packet this structure is associated with
-     * is received and the time when it should be decoded, in periods of a 27MHz
-     * clock.
-     *
-     * UINT64_MAX when unknown or unspecified.
-     */
-    uint64_t vbv_delay;
-} AVCPBProperties;
-
-/**
- * This structure supplies correlation between a packet timestamp and a wall clock
- * production time. The definition follows the Producer Reference Time ('prft')
- * as defined in ISO/IEC 14496-12
- */
-typedef struct AVProducerReferenceTime {
-    /**
-     * A UTC timestamp, in microseconds, since Unix epoch (e.g, av_gettime()).
-     */
-    int64_t wallclock;
-    int flags;
-} AVProducerReferenceTime;
-
 /**
  * The decoder will keep a reference to the frame and may reuse it later.
  */
@@ -3300,32 +3183,12 @@ void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
  */
 void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
 
-/**
- * Encode extradata length to a buffer. Used by xiph codecs.
- *
- * @param s buffer to write to; must be at least (v/255+1) bytes long
- * @param v size of extradata in bytes
- * @return number of bytes written to the buffer.
- */
-unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
-
 /**
  * @return a positive value if s is open (i.e. avcodec_open2() was called on it
  * with no corresponding avcodec_close()), 0 otherwise.
  */
 int avcodec_is_open(AVCodecContext *s);
 
-/**
- * Allocate a CPB properties structure and initialize its fields to default
- * values.
- *
- * @param size if non-NULL, the size of the allocated struct will be written
- *             here. This is useful for embedding it in side data.
- *
- * @return the newly allocated struct or NULL on failure
- */
-AVCPBProperties *av_cpb_properties_alloc(size_t *size);
-
 /**
  * @}
  */

libavcodec/defs.h

@@ -0,0 +1,170 @@
+/*
+ *
+ * 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_DEFS_H
+#define AVCODEC_DEFS_H
+
+/**
+ * @file
+ * @ingroup libavc
+ * Misc types and constants that do not belong anywhere else.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/**
+ * @ingroup lavc_decoding
+ * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
+ * This is mainly needed because some optimized bitstream readers read
+ * 32 or 64 bit at once and could read over the end.<br>
+ * Note: If the first 23 bits of the additional bytes are not 0, then damaged
+ * MPEG bitstreams could cause overread and segfault.
+ */
+#define AV_INPUT_BUFFER_PADDING_SIZE 64
+
+/**
+ * @ingroup lavc_decoding
+ */
+enum AVDiscard{
+    /* We leave some space between them for extensions (drop some
+     * keyframes for intra-only or drop just some bidir frames). */
+    AVDISCARD_NONE    =-16, ///< discard nothing
+    AVDISCARD_DEFAULT =  0, ///< discard useless packets like 0 size packets in avi
+    AVDISCARD_NONREF  =  8, ///< discard all non reference
+    AVDISCARD_BIDIR   = 16, ///< discard all bidirectional frames
+    AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
+    AVDISCARD_NONKEY  = 32, ///< discard all frames except keyframes
+    AVDISCARD_ALL     = 48, ///< discard all
+};
+
+enum AVAudioServiceType {
+    AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
+    AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
+    AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
+    AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
+    AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
+    AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
+    AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
+    AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
+    AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
+    AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
+};
+
+/**
+ * Pan Scan area.
+ * This specifies the area which should be displayed.
+ * Note there may be multiple such areas for one frame.
+ */
+typedef struct AVPanScan {
+    /**
+     * id
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int id;
+
+    /**
+     * width and height in 1/16 pel
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int width;
+    int height;
+
+    /**
+     * position of the top left corner in 1/16 pel for up to 3 fields/frames
+     * - encoding: Set by user.
+     * - decoding: Set by libavcodec.
+     */
+    int16_t position[3][2];
+} AVPanScan;
+
+/**
+ * This structure describes the bitrate properties of an encoded bitstream. It
+ * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
+ * parameters for H.264/HEVC.
+ */
+typedef struct AVCPBProperties {
+    /**
+     * Maximum bitrate of the stream, in bits per second.
+     * Zero if unknown or unspecified.
+     */
+    int64_t max_bitrate;
+    /**
+     * Minimum bitrate of the stream, in bits per second.
+     * Zero if unknown or unspecified.
+     */
+    int64_t min_bitrate;
+    /**
+     * Average bitrate of the stream, in bits per second.
+     * Zero if unknown or unspecified.
+     */
+    int64_t avg_bitrate;
+
+    /**
+     * The size of the buffer to which the ratecontrol is applied, in bits.
+     * Zero if unknown or unspecified.
+     */
+    int64_t buffer_size;
+
+    /**
+     * The delay between the time the packet this structure is associated with
+     * is received and the time when it should be decoded, in periods of a 27MHz
+     * clock.
+     *
+     * UINT64_MAX when unknown or unspecified.
+     */
+    uint64_t vbv_delay;
+} AVCPBProperties;
+
+/**
+ * Allocate a CPB properties structure and initialize its fields to default
+ * values.
+ *
+ * @param size if non-NULL, the size of the allocated struct will be written
+ *             here. This is useful for embedding it in side data.
+ *
+ * @return the newly allocated struct or NULL on failure
+ */
+AVCPBProperties *av_cpb_properties_alloc(size_t *size);
+
+/**
+ * This structure supplies correlation between a packet timestamp and a wall clock
+ * production time. The definition follows the Producer Reference Time ('prft')
+ * as defined in ISO/IEC 14496-12
+ */
+typedef struct AVProducerReferenceTime {
+    /**
+     * A UTC timestamp, in microseconds, since Unix epoch (e.g, av_gettime()).
+     */
+    int64_t wallclock;
+    int flags;
+} AVProducerReferenceTime;
+
+/**
+ * Encode extradata length to a buffer. Used by xiph codecs.
+ *
+ * @param s buffer to write to; must be at least (v/255+1) bytes long
+ * @param v size of extradata in bytes
+ * @return number of bytes written to the buffer.
+ */
+unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
+
+#endif // AVCODEC_DEFS_H