deps-libff: Add ff codec/format utility functions

This adds utility functions for determining which
codecs and formats are supported by loaded FFMpeg
libraries.  This includes validating the codecs that
a particular format supports.

deps/libff/CMakeLists.txt

@@ -19,6 +19,7 @@ set(libff_HEADERS
 	libff/ff-packet-queue.h
 	libff/ff-threading.h
 	libff/ff-timer.h
+	libff/ff-util.h
 	#
 	libff/ff-demuxer.h
 	#
@@ -30,6 +31,7 @@ set(libff_SOURCES
 	libff/ff-clock.c
 	libff/ff-packet-queue.c
 	libff/ff-timer.c
+	libff/ff-util.c
 	#
 	libff/ff-demuxer.c
 	#

deps/libff/libff/ff-util.c

@@ -0,0 +1,397 @@
+/*
+ * Copyright (c) 2015 John R. Bradley <jrb@turrettech.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ff-util.h"
+
+#include <libavcodec/avcodec.h>
+#include <libavdevice/avdevice.h>
+#include <libavformat/avformat.h>
+#include <libavutil/log.h>
+
+#include <stdbool.h>
+
+struct ff_format_desc {
+	const char *name;
+	const char *long_name;
+	const char *mime_type;
+	enum AVCodecID audio_codec;
+	enum AVCodecID video_codec;
+	const struct AVCodecTag * const *codec_tags;
+	const struct ff_format_desc *next;
+};
+
+struct ff_codec_desc {
+	const char *name;
+	const char *long_name;
+	int id;
+	bool alias;
+	const char *base_name;
+	enum ff_codec_type type;
+	const struct ff_codec_desc *next;
+};
+
+void ff_init()
+{
+	av_register_all();
+	avdevice_register_all();
+	avcodec_register_all();
+	avformat_network_init();
+}
+
+const char *ff_codec_name_from_id(int codec_id)
+{
+	AVCodec *codec = avcodec_find_encoder(codec_id);
+	if (codec != NULL)
+		return codec->name;
+	else
+		return NULL;
+}
+
+static bool get_codecs(const AVCodecDescriptor*** descs, unsigned int *size)
+{
+	const AVCodecDescriptor *desc = NULL;
+	const AVCodecDescriptor **codecs;
+	unsigned int codec_count = 0;
+	unsigned int i = 0;
+
+	while ((desc = avcodec_descriptor_next(desc)))
+		codec_count++;
+
+	codecs = av_calloc(codec_count, sizeof(AVCodecDescriptor *));
+
+	if (codecs == NULL) {
+		av_log(NULL, AV_LOG_ERROR, "unable to allocate sorted codec "
+				"array with size %d", codec_count);
+		return false;
+	}
+
+	while ((desc = avcodec_descriptor_next(desc)))
+		codecs[i++] = desc;
+
+	*size = codec_count;
+	*descs = codecs;
+	return true;
+}
+
+static const AVCodec *next_codec_for_id(enum AVCodecID id, const AVCodec *prev)
+{
+    while ((prev = av_codec_next(prev))) {
+        if (prev->id == id && av_codec_is_encoder(prev))
+            return prev;
+    }
+
+    return NULL;
+}
+
+static void add_codec_to_list(const struct ff_format_desc *format_desc,
+		struct ff_codec_desc **first, struct ff_codec_desc **current,
+		enum AVCodecID id, const AVCodec *codec)
+{
+	if (codec == NULL)
+		codec = avcodec_find_encoder(id);
+
+	// No codec, or invalid id
+	if (codec == NULL)
+		return;
+
+	// Not an encoding codec
+	if (!av_codec_is_encoder(codec))
+		return;
+
+	// Format doesn't support this codec
+	unsigned int tag = av_codec_get_tag(format_desc->codec_tags,
+			codec->id);
+	if (tag == 0)
+		return;
+
+	struct ff_codec_desc *d = av_mallocz(sizeof(struct ff_codec_desc));
+
+	d->name = codec->name;
+	d->long_name = codec->long_name;
+	d->id = codec->id;
+	AVCodec *base_codec = avcodec_find_encoder(codec->id);
+	if (strcmp(base_codec->name, codec->name) != 0) {
+		d->alias = true;
+		d->base_name = base_codec->name;
+	}
+
+	switch (codec->type) {
+	case AVMEDIA_TYPE_AUDIO:
+		d->type = FF_CODEC_AUDIO;
+		break;
+	case AVMEDIA_TYPE_VIDEO:
+		d->type = FF_CODEC_VIDEO;
+		break;
+	default:
+		d->type = FF_CODEC_UNKNOWN;
+	}
+
+	if (*current != NULL)
+		(*current)->next = d;
+	else
+		*first = d;
+
+	*current = d;
+}
+
+static void get_codecs_for_id(const struct ff_format_desc *format_desc,
+		struct ff_codec_desc **first, struct ff_codec_desc **current,
+		enum AVCodecID id)
+{
+	const AVCodec *codec = NULL;
+	while ((codec = next_codec_for_id(id, codec)))
+		add_codec_to_list(format_desc, first, current, codec->id,
+				codec);
+}
+
+const struct ff_codec_desc *ff_codec_supported(
+		const struct ff_format_desc *format_desc)
+{
+	const AVCodecDescriptor **codecs;
+	unsigned int size;
+	unsigned int i;
+	struct ff_codec_desc *current = NULL;
+	struct ff_codec_desc *first = NULL;
+
+	if (!get_codecs(&codecs, &size))
+		return NULL;
+
+	for(i = 0; i < size; i++) {
+		const AVCodecDescriptor *codec = codecs[i];
+		get_codecs_for_id(format_desc, &first, &current, codec->id);
+	}
+
+	av_free((void *)codecs);
+
+	return first;
+}
+
+const char *ff_codec_desc_name(const struct ff_codec_desc *codec_desc)
+{
+	if (codec_desc != NULL)
+		return codec_desc->name;
+	else
+		return NULL;
+}
+
+const char *ff_codec_desc_long_name(const struct ff_codec_desc *codec_desc)
+{
+	if (codec_desc != NULL)
+		return codec_desc->long_name;
+	else
+		return NULL;
+}
+
+bool ff_codec_desc_is_alias(const struct ff_codec_desc *codec_desc)
+{
+	if (codec_desc != NULL)
+		return codec_desc->alias;
+	else
+		return false;
+}
+
+const char *ff_codec_desc_base_name(const struct ff_codec_desc *codec_desc)
+{
+	if (codec_desc != NULL)
+		return codec_desc->base_name;
+	else
+		return NULL;
+}
+
+enum ff_codec_type ff_codec_desc_type(const struct ff_codec_desc *codec_desc)
+{
+	if (codec_desc != NULL)
+		return codec_desc->type;
+	else
+		return FF_CODEC_UNKNOWN;
+}
+
+const struct ff_codec_desc *ff_codec_desc_next(
+		const struct ff_codec_desc *codec_desc)
+{
+	if (codec_desc != NULL)
+		return codec_desc->next;
+	else
+		return NULL;
+}
+
+int ff_codec_desc_id(const struct ff_codec_desc *codec_desc)
+{
+	if (codec_desc != NULL)
+		return codec_desc->id;
+	else
+		return AV_CODEC_ID_NONE;
+}
+
+void ff_codec_desc_free(const struct ff_codec_desc *codec_desc)
+{
+	const struct ff_codec_desc *desc = codec_desc;
+	while(desc != NULL) {
+		const struct ff_codec_desc *next = desc->next;
+		av_free((void *)desc);
+		desc = next;
+	}
+}
+
+static inline bool is_output_device(const AVClass *avclass)
+{
+	if (!avclass)
+		return 0;
+
+	switch (avclass->category) {
+	case AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT:
+	case AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT:
+	case AV_CLASS_CATEGORY_DEVICE_OUTPUT:
+		return true;
+	default:
+		return false;
+	}
+}
+
+const struct ff_format_desc *ff_format_supported()
+{
+	AVOutputFormat *output_format = NULL;
+	struct ff_format_desc *desc = NULL;
+	struct ff_format_desc *current = NULL;
+
+	while ((output_format = av_oformat_next(output_format))) {
+		struct ff_format_desc *d;
+		if (is_output_device(output_format->priv_class))
+			continue;
+
+		d = av_mallocz(sizeof(struct ff_format_desc));
+
+		d->audio_codec = output_format->audio_codec;
+		d->video_codec = output_format->video_codec;
+		d->name = output_format->name;
+		d->long_name = output_format->long_name;
+		d->mime_type = output_format->mime_type;
+		d->codec_tags = output_format->codec_tag;
+
+		if (current != NULL) {
+			current->next = d;
+			current = d;
+		} else {
+			desc = current = d;
+		}
+	}
+
+	return desc;
+}
+
+const char *ff_format_desc_name(const struct ff_format_desc *format_desc)
+{
+	if (format_desc != NULL)
+		return format_desc->name;
+	else
+		return NULL;
+}
+
+const char *ff_format_desc_long_name(const struct ff_format_desc *format_desc)
+{
+	if (format_desc != NULL)
+		return format_desc->long_name;
+	else
+		return NULL;
+}
+
+const char *ff_format_desc_mime_type(const struct ff_format_desc *format_desc)
+{
+	if (format_desc != NULL)
+		return format_desc->mime_type;
+	else
+		return NULL;
+}
+
+bool ff_format_desc_has_audio(const struct ff_format_desc *format_desc)
+{
+	if (format_desc != NULL)
+		return format_desc->audio_codec != AV_CODEC_ID_NONE;
+	else
+		return false;
+}
+
+bool ff_format_desc_has_video(const struct ff_format_desc *format_desc)
+{
+	if (format_desc != NULL)
+		return format_desc->video_codec != AV_CODEC_ID_NONE;
+	else
+		return false;
+}
+
+int ff_format_desc_audio(const struct ff_format_desc *format_desc)
+{
+	if (format_desc != NULL)
+		return format_desc->audio_codec;
+	else
+		return false;
+}
+
+int ff_format_desc_video(const struct ff_format_desc *format_desc)
+{
+	if (format_desc != NULL)
+		return format_desc->video_codec;
+	else
+		return false;
+}
+
+const struct ff_format_desc *ff_format_desc_next(
+		const struct ff_format_desc *format_desc)
+{
+	if (format_desc != NULL)
+		return format_desc->next;
+	else
+		return NULL;
+}
+
+static const char *get_encoder_name(const struct ff_format_desc *format_desc,
+		enum AVCodecID codec_id)
+{
+	AVCodec *codec = avcodec_find_encoder(codec_id);
+	if (codec == NULL && codec_id == AV_CODEC_ID_NONE)
+		return NULL;
+	else if (codec == NULL)
+		return format_desc->name;
+	else
+		return codec->name;
+}
+
+const char *ff_format_desc_get_default_name(
+		const struct ff_format_desc *format_desc,
+		enum ff_codec_type codec_type)
+{
+	switch (codec_type)
+	{
+		case FF_CODEC_AUDIO:
+			return get_encoder_name(format_desc,
+					format_desc->audio_codec);
+		case FF_CODEC_VIDEO:
+			return get_encoder_name(format_desc,
+					format_desc->video_codec);
+		default:
+			return NULL;
+	}
+}
+
+void ff_format_desc_free(const struct ff_format_desc *format_desc)
+{
+	const struct ff_format_desc *desc = format_desc;
+	while(desc != NULL) {
+		const struct ff_format_desc *next = desc->next;
+		av_free((void *)desc);
+		desc = next;
+	}
+}

deps/libff/libff/ff-util.h

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2015 John R. Bradley <jrb@turrettech.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum ff_codec_type {
+	FF_CODEC_AUDIO,
+	FF_CODEC_VIDEO,
+	FF_CODEC_UNKNOWN
+};
+
+struct ff_format_desc;
+struct ff_codec_desc;
+
+void ff_init();
+
+const char *ff_codec_name_from_id(int codec_id);
+
+// Codec Description
+const struct ff_codec_desc *ff_codec_supported(
+		const struct ff_format_desc *format_desc);
+void ff_codec_desc_free(const struct ff_codec_desc *codec_desc);
+const char *ff_codec_desc_name(const struct ff_codec_desc *codec_desc);
+const char *ff_codec_desc_long_name(const struct ff_codec_desc *codec_desc);
+enum ff_codec_type ff_codec_desc_type(const struct ff_codec_desc *codec_desc);
+bool ff_codec_desc_is_alias(const struct ff_codec_desc *codec_desc);
+const char *ff_codec_desc_base_name(const struct ff_codec_desc *codec_desc);
+int ff_codec_desc_id(const struct ff_codec_desc *codec_desc);
+const struct ff_codec_desc *ff_codec_desc_next(
+		const struct ff_codec_desc *codec_desc);
+
+// Format Description
+const struct ff_format_desc *ff_format_supported();
+void ff_format_desc_free(const struct ff_format_desc *format_desc);
+const char *ff_format_desc_name(const struct ff_format_desc *format_desc);
+const char *ff_format_desc_long_name(const struct ff_format_desc *format_desc);
+const char *ff_format_desc_mime_type(const struct ff_format_desc *format_desc);
+bool ff_format_desc_has_audio(const struct ff_format_desc *format_desc);
+bool ff_format_desc_has_video(const struct ff_format_desc *format_desc);
+int ff_format_desc_audio(const struct ff_format_desc *format_desc);
+int ff_format_desc_video(const struct ff_format_desc *format_desc);
+const char *ff_format_desc_get_default_name(
+		const struct ff_format_desc *format_desc,
+		enum ff_codec_type codec_type);
+const struct ff_format_desc *ff_format_desc_next(
+		const struct ff_format_desc *format_desc);
+
+#ifdef __cplusplus
+}
+#endif