avdevice/avdevice: Deprecate AVDevice Capabilities API

It has been added in 6db42a2b6b22e6f1928fafcf3faa67ed78201004,
yet since then none of the necessary create/free_device_capabilities
functions has been implemented, making this API completely useless.

Because of this one can already simplify
avdevice_capabilities_free/create and can already remove the function
pointers at the next major bump; given that the documentation explicitly
states that av_device_capabilities is not to be used by a user, it's
options can already be removed (save for the sentinel).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

doc/APIchanges

@@ -15,6 +15,10 @@ libavutil:     2017-10-21
 
 API changes, most recent first:
 
+2021-02-14 - xxxxxxxxxx - lavd 58.12.100 - avdevice.h
+  Deprecated avdevice_capabilities_create() and
+  avdevice_capabilities_free().
+
 2021-02-xx - xxxxxxxxxx - lavu 56.xx.100 - common.h
   Add FFABS64U()
 

libavdevice/avdevice.c

@@ -27,39 +27,11 @@
 #include "libavutil/ffversion.h"
 const char av_device_ffversion[] = "FFmpeg version " FFMPEG_VERSION;
 
-#define E AV_OPT_FLAG_ENCODING_PARAM
-#define D AV_OPT_FLAG_DECODING_PARAM
-#define A AV_OPT_FLAG_AUDIO_PARAM
-#define V AV_OPT_FLAG_VIDEO_PARAM
-#define OFFSET(x) offsetof(AVDeviceCapabilitiesQuery, x)
-
+#if FF_API_DEVICE_CAPABILITIES
 const AVOption av_device_capabilities[] = {
-    { "codec", "codec", OFFSET(codec), AV_OPT_TYPE_INT,
-        {.i64 = AV_CODEC_ID_NONE}, AV_CODEC_ID_NONE, INT_MAX, E|D|A|V },
-    { "sample_format", "sample format", OFFSET(sample_format), AV_OPT_TYPE_SAMPLE_FMT,
-        {.i64 = AV_SAMPLE_FMT_NONE}, AV_SAMPLE_FMT_NONE, INT_MAX, E|D|A },
-    { "sample_rate", "sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT,
-        {.i64 = -1}, -1, INT_MAX, E|D|A },
-    { "channels", "channels", OFFSET(channels), AV_OPT_TYPE_INT,
-        {.i64 = -1}, -1, INT_MAX, E|D|A },
-    { "channel_layout", "channel layout", OFFSET(channel_layout), AV_OPT_TYPE_CHANNEL_LAYOUT,
-        {.i64 = -1}, -1, INT_MAX, E|D|A },
-    { "pixel_format", "pixel format", OFFSET(pixel_format), AV_OPT_TYPE_PIXEL_FMT,
-        {.i64 = AV_PIX_FMT_NONE}, AV_PIX_FMT_NONE, INT_MAX, E|D|V },
-    { "window_size", "window size", OFFSET(window_width), AV_OPT_TYPE_IMAGE_SIZE,
-        {.str = NULL}, -1, INT_MAX, E|D|V },
-    { "frame_size", "frame size", OFFSET(frame_width), AV_OPT_TYPE_IMAGE_SIZE,
-        {.str = NULL}, -1, INT_MAX, E|D|V },
-    { "fps", "fps", OFFSET(fps), AV_OPT_TYPE_RATIONAL,
-        {.dbl = -1}, -1, INT_MAX, E|D|V },
     { NULL }
 };
-
-#undef E
-#undef D
-#undef A
-#undef V
-#undef OFFSET
+#endif
 
 unsigned avdevice_version(void)
 {
@@ -94,49 +66,18 @@ int avdevice_dev_to_app_control_message(struct AVFormatContext *s, enum AVDevToA
     return s->control_message_cb(s, type, data, data_size);
 }
 
+#if FF_API_DEVICE_CAPABILITIES
 int avdevice_capabilities_create(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s,
                                  AVDictionary **device_options)
 {
-    int ret;
-    av_assert0(s && caps);
-    av_assert0(s->iformat || s->oformat);
-    if ((s->oformat && !s->oformat->create_device_capabilities) ||
-        (s->iformat && !s->iformat->create_device_capabilities))
-        return AVERROR(ENOSYS);
-    *caps = av_mallocz(sizeof(**caps));
-    if (!(*caps))
-        return AVERROR(ENOMEM);
-    (*caps)->device_context = s;
-    if (((ret = av_opt_set_dict(s->priv_data, device_options)) < 0))
-        goto fail;
-    if (s->iformat) {
-        if ((ret = s->iformat->create_device_capabilities(s, *caps)) < 0)
-            goto fail;
-    } else {
-        if ((ret = s->oformat->create_device_capabilities(s, *caps)) < 0)
-            goto fail;
-    }
-    av_opt_set_defaults(*caps);
-    return 0;
-  fail:
-    av_freep(caps);
-    return ret;
+    return AVERROR(ENOSYS);
 }
 
 void avdevice_capabilities_free(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s)
 {
-    if (!s || !caps || !(*caps))
-        return;
-    av_assert0(s->iformat || s->oformat);
-    if (s->iformat) {
-        if (s->iformat->free_device_capabilities)
-            s->iformat->free_device_capabilities(s, *caps);
-    } else {
-        if (s->oformat->free_device_capabilities)
-            s->oformat->free_device_capabilities(s, *caps);
-    }
-    av_freep(caps);
+    return;
 }
+#endif
 
 int avdevice_list_devices(AVFormatContext *s, AVDeviceInfoList **device_list)
 {

libavdevice/avdevice.h

@@ -321,6 +321,7 @@ int avdevice_dev_to_app_control_message(struct AVFormatContext *s,
                                         enum AVDevToAppMessageType type,
                                         void *data, size_t data_size);
 
+#if FF_API_DEVICE_CAPABILITIES
 /**
  * Following API allows user to probe device capabilities (supported codecs,
  * pixel formats, sample formats, resolutions, channel counts, etc).
@@ -416,6 +417,7 @@ typedef struct AVDeviceCapabilitiesQuery {
 /**
  * AVOption table used by devices to implement device capabilities API. Should not be used by a user.
  */
+attribute_deprecated
 extern const AVOption av_device_capabilities[];
 
 /**
@@ -435,6 +437,7 @@ extern const AVOption av_device_capabilities[];
  *
  * @return >= 0 on success, negative otherwise.
  */
+attribute_deprecated
 int avdevice_capabilities_create(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s,
                                  AVDictionary **device_options);
 
@@ -444,7 +447,9 @@ int avdevice_capabilities_create(AVDeviceCapabilitiesQuery **caps, AVFormatConte
  * @param caps Device capabilities data to be freed.
  * @param s    Context of the device.
  */
+attribute_deprecated
 void avdevice_capabilities_free(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s);
+#endif
 
 /**
  * Structure describes basic parameters of the device.

libavdevice/version.h

@@ -28,8 +28,8 @@
 #include "libavutil/version.h"
 
 #define LIBAVDEVICE_VERSION_MAJOR  58
-#define LIBAVDEVICE_VERSION_MINOR  11
-#define LIBAVDEVICE_VERSION_MICRO 103
+#define LIBAVDEVICE_VERSION_MINOR  12
+#define LIBAVDEVICE_VERSION_MICRO 100
 
 #define LIBAVDEVICE_VERSION_INT AV_VERSION_INT(LIBAVDEVICE_VERSION_MAJOR, \
                                                LIBAVDEVICE_VERSION_MINOR, \
@@ -46,5 +46,8 @@
  * dropped at a future version bump. The defines themselves are not part of
  * the public API and may change, break or disappear at any time.
  */
+#ifndef FF_API_DEVICE_CAPABILITIES
+#define FF_API_DEVICE_CAPABILITIES (LIBAVDEVICE_VERSION_MAJOR < 60)
+#endif
 
 #endif /* AVDEVICE_VERSION_H */

libavformat/avformat.h

@@ -590,6 +590,7 @@ typedef struct AVOutputFormat {
      * @see avdevice_list_devices() for more details.
      */
     int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
+#if LIBAVFORMAT_VERSION_MAJOR < 59
     /**
      * Initialize device capabilities submodule.
      * @see avdevice_capabilities_create() for more details.
@@ -600,6 +601,7 @@ typedef struct AVOutputFormat {
      * @see avdevice_capabilities_free() for more details.
      */
     int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
+#endif
     enum AVCodecID data_codec; /**< default data codec */
     /**
      * Initialize format. May allocate data here, and set any AVFormatContext or
@@ -769,6 +771,7 @@ typedef struct AVInputFormat {
      */
     int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
 
+#if LIBAVFORMAT_VERSION_MAJOR < 59
     /**
      * Initialize device capabilities submodule.
      * @see avdevice_capabilities_create() for more details.
@@ -780,6 +783,7 @@ typedef struct AVInputFormat {
      * @see avdevice_capabilities_free() for more details.
      */
     int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
+#endif
 } AVInputFormat;
 /**
  * @}