[FFmpeg-devel] [PATCH 5/8] lavd: add device capabilities API

Lukasz Marek lukasz.m.luki at gmail.com
Sat Feb 22 23:33:39 CET 2014


TODO: bump minors, update APIchages

Signed-off-by: Lukasz Marek <lukasz.m.luki at gmail.com>
---
 libavdevice/avdevice.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++
 libavdevice/avdevice.h | 79 ++++++++++++++++++++++++++++++++++++++++
 libavformat/avformat.h | 36 +++++++++++++++++++
 3 files changed, 212 insertions(+)

diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c
index 1031afd..911e92b 100644
--- a/libavdevice/avdevice.c
+++ b/libavdevice/avdevice.c
@@ -17,9 +17,46 @@
  */
 
 #include "libavutil/avassert.h"
+#include "libavcodec/avcodec.h"
 #include "avdevice.h"
 #include "config.h"
 
+#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)
+
+const AVOption av_device_capabilities[] = {
+    { "device_name", "device name", OFFSET(device_name), AV_OPT_TYPE_STRING,
+        {.str = NULL}, 0, 0, E|D|A|V },
+    { "codec", "codec", OFFSET(codec), AV_OPT_TYPE_INT,
+        {.i64 = AV_CODEC_ID_NONE}, AV_CODEC_ID_NONE, INT_MAX, E|D|A|V },
+    { "format", "format", OFFSET(format), AV_OPT_TYPE_INT,
+        {.i64 = -1}, -1, INT_MAX, E|D|A|V },
+
+    { "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_INT64,
+        {.i64 = -1}, -1, INT_MAX, E|D|A },
+
+    { "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
+
 unsigned avdevice_version(void)
 {
     av_assert0(LIBAVDEVICE_VERSION_MICRO >= 100);
@@ -93,6 +130,66 @@ int avdevice_dev_to_app_control_message(struct AVFormatContext *s, enum AVDevToA
     return s->control_message_cb(s, type, data, data_size);
 }
 
+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 (device_options && ((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;
+}
+
+int avdevice_capabilities_apply(AVDeviceCapabilitiesQuery *caps, AVFormatContext *s,
+                               enum AVDeviceCapabilitiesApplyStrategy strategy)
+{
+    av_assert0(s);
+    av_assert0(s->iformat || s->oformat);
+    if (s->iformat) {
+        if (!s->iformat->apply_device_capabilities)
+            return AVERROR(ENOSYS);
+        return s->iformat->apply_device_capabilities(s, caps, strategy);
+    }
+    if (!s->oformat->apply_device_capabilities)
+        return AVERROR(ENOSYS);
+    return s->oformat->apply_device_capabilities(s, caps, strategy);
+}
+
+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_free((*caps)->device_name);
+    av_freep(caps);
+}
+
 int avdevice_list_devices(AVFormatContext *s, AVDeviceInfoList **device_list)
 {
     av_assert0(s);
diff --git a/libavdevice/avdevice.h b/libavdevice/avdevice.h
index 47bf8f4..708ef65 100644
--- a/libavdevice/avdevice.h
+++ b/libavdevice/avdevice.h
@@ -43,6 +43,9 @@
  * @}
  */
 
+#include "libavutil/log.h"
+#include "libavutil/opt.h"
+#include "libavutil/dict.h"
 #include "libavformat/avformat.h"
 
 /**
@@ -208,6 +211,82 @@ int avdevice_dev_to_app_control_message(struct AVFormatContext *s,
                                         void *data, size_t data_size);
 
 /**
+ * Structure describes device settings.
+ *
+ * It is used by devices in conjuntion with av_device_capabilities AVOption table
+ * to to implement capabilities probing API based on AVOption API.
+ */
+typedef struct AVDeviceCapabilitiesQuery {
+    const AVClass *class;
+    char *device_name;
+    AVFormatContext *device_context;
+    enum AVCodecID codec;
+    int format;                          /**< AVSampleFormat or AVPixelFormat */
+    int sample_rate;
+    int channels;
+    int64_t channel_layout;
+    int window_width;
+    int window_height;
+    int frame_width;
+    int frame_height;
+    AVRational fps;
+} AVDeviceCapabilitiesQuery;
+
+extern const AVOption av_device_capabilities[];
+
+enum AVDeviceCapabilitiesApplyStrategy {
+    AVDEVICE_STRATEGY_APPLY_IF_VALID,                /**< apply settings when valid */
+    AVDEVICE_STRATEGY_FIX_TO_THE_NEAREST,            /**< adjust structure only to the nearest valid value */
+    AVDEVICE_STRATEGY_FIX_TO_THE_BEST,               /**< adjust structure only to the best valid value */
+    AVDEVICE_STRATEGY_FIX_TO_THE_NEAREST_AND_APPLY,  /**< adjust values to the nearest valid value and apply */
+    AVDEVICE_STRATEGY_FIX_TO_THE_BEST_AND_APPLY      /**< adjust values to the best valid value and apply */
+};
+
+/**
+ * Initialize capabilities probing API based on AVOption API.
+ *
+ * avdevice_capabilities_free() must be called when query capabilities API is
+ * not used anymore.
+ *
+ * @note: It is not allowed to free device context before calling avdevice_capabilities_free().
+ *
+ * @param caps           device configuration
+ * @param s              device context
+ * @param device_options device options
+ * @return >= 0 on success, negative otherwise.
+ */
+int avdevice_capabilities_create(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s,
+                                 AVDictionary **device_options);
+
+/**
+ * Apply set parameters to device context and release data allocated
+ * by avdevice_init_device_capabilities().
+ *
+ * All set capabilities are validated and tested. When configuration is not
+ * valid then adjustment takes place according to provided strategy.
+ * When it is required by provided strategy, set capabilities are applied into
+ * device context. Mapping between capablities and device settings are device-specific.
+ * In particular output device may not apply all parameters to the context,
+ * but use stream properties when avformat_write_header() is called.
+ *
+ * @param caps     device configuration
+ * @param s        device context
+ * @param strategy apply strategy
+ * @return 0 when configuration is not applied, 1 when configuration is applied,
+ *         negative on error.
+ */
+int avdevice_capabilities_apply(AVDeviceCapabilitiesQuery *caps, AVFormatContext *s,
+                                enum AVDeviceCapabilitiesApplyStrategy strategy);
+
+/**
+ * Free resources created by avdevice_capabilities_create()
+ *
+ * @param caps device configuration
+ * @param s    device context
+ */
+void avdevice_capabilities_free(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s);
+
+/**
  * Structure describes basic parameters of the device.
  */
 typedef struct AVDeviceInfo {
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 52eeb61..e2d36f6 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -262,6 +262,7 @@
 struct AVFormatContext;
 
 struct AVDeviceInfoList;
+struct AVDeviceCapabilitiesQuery;
 
 /**
  * @defgroup metadata_api Public Metadata API
@@ -531,6 +532,22 @@ typedef struct AVOutputFormat {
      * @see avdevice_list_devices() for more details.
      */
     int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
+    /**
+     * Initialize device capabilities submodule.
+     * @see avdevice_capabilities_create() for more details.
+     */
+    int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
+    /**
+     * Apply currently set device capabilities to device context.
+     * @see avdevice_capabilities_apply() for more details.
+     */
+    int (*apply_device_capabilities)(struct AVFormatContext *s,
+                                     struct AVDeviceCapabilitiesQuery *caps, int strategy);
+    /**
+     * Free device capabilities submodule.
+     * @see avdevice_capabilities_free() for more details.
+     */
+    int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
 } AVOutputFormat;
 /**
  * @}
@@ -665,6 +682,25 @@ typedef struct AVInputFormat {
      * @see avdevice_list_devices() for more details.
      */
     int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
+
+    /**
+     * Initialize device capabilities submodule.
+     * @see avdevice_capabilities_create() for more details.
+     */
+    int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
+
+    /**
+     * Apply currently set device capabilities to device context.
+     * @see avdevice_capabilities_apply() for more details.
+     */
+    int (*apply_device_capabilities)(struct AVFormatContext *s,
+                                     struct AVDeviceCapabilitiesQuery *caps, int strategy);
+
+    /**
+     * Free device capabilities submodule.
+     * @see avdevice_capabilities_free() for more details.
+     */
+    int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
 } AVInputFormat;
 /**
  * @}
-- 
1.8.3.2



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