init

.gitignore

@@ -0,0 +1,6 @@
+*~
+*.o
+extract-artwork
+README.html
+extract-artwork-*.tar.xz
+extract-artwork-*.tar.xz.asc

Makefile

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+# extract-artwork - Extract artwork from media files
+
+CC	:= gcc
+MD	:= markdown
+INSTALL	:= install
+CP	:= cp
+RM	:= rm
+CFLAGS	+= -std=c11 -O2 -Wall -Werror
+CFLAGS	+= $(shell pkg-config --cflags --libs libavformat libavutil)
+# this is just a fallback in case you do not use git but downloaded
+# a release tarball...
+VERSION := 0.0.1
+
+all: extract-artwork README.html
+
+extract-artwork: extract-artwork.c
+	$(CC) $(CFLAGS) -o extract-artwork extract-artwork.c
+
+README.html: README.md
+	$(MD) README.md > README.html
+
+install: install-bin install-doc
+
+install-bin: extract-artwork
+	$(INSTALL) -D -m0755 extract-artwork $(DESTDIR)/usr/bin/extract-artwork
+
+install-doc: README.html
+	$(INSTALL) -D -m0644 README.md $(DESTDIR)/usr/share/doc/extract-artwork/README.md
+	$(INSTALL) -D -m0644 README.html $(DESTDIR)/usr/share/doc/extract-artwork/README.html
+
+clean:
+	$(RM) -f *.o *~ README.html extract-artwork
+
+release:
+	git archive --format=tar.xz --prefix=extract-artwork-$(VERSION)/ $(VERSION) > extract-artwork-$(VERSION).tar.xz
+	gpg -ab extract-artwork-$(VERSION).tar.xz

README.md

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+extract-artwork
+===============
+
+Extract artwork from media files

extract-artwork.c

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+/*
+ * (C) 2015 by Christian Hesse <mail@eworm.de>
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ * This is an example code skeleton provided by vim-skeleton.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <libavformat/avformat.h>
+
+int main(int argc, char **argv) {
+	unsigned int i, j;
+	FILE * album_art;
+	char * album_art_file = NULL;
+	AVPacket pkt;
+	AVFormatContext * pFormatCtx;
+
+	if (argc < 2) {
+		printf("usage: %s file1.mp3 [file2.mp3 ...]\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	/* libav */
+	av_register_all();
+
+	/* only fatal messages from libav */
+	av_log_set_level(AV_LOG_FATAL);
+
+	pFormatCtx = avformat_alloc_context();
+
+	for (i = 1; i < argc; i++) {
+		if (avformat_open_input(&pFormatCtx, argv[i], NULL, NULL) != 0) {
+			fprintf(stderr, "%s: failed to open file for reading", argv[i]);
+			goto next;
+		}
+
+		/* only mp3 file contain artwork, so ignore others */
+		if (strcmp(pFormatCtx->iformat->name, "mp3") != 0) {
+			fprintf(stderr, "%s: not a mp3 file\n", argv[i]);
+			goto next;
+		}
+
+		if (pFormatCtx->iformat->read_header(pFormatCtx) < 0) {
+			fprintf(stderr, "%s: could not read the format header\n", argv[i]);
+			goto next;
+		}
+
+		/* find the first attached picture, if available */
+		for (j = 0; j < pFormatCtx->nb_streams; j++) {
+			if (pFormatCtx->streams[j]->disposition & AV_DISPOSITION_ATTACHED_PIC) {
+				pkt = pFormatCtx->streams[j]->attached_pic;
+
+				album_art_file = malloc(strlen(argv[i]) + 9);
+				sprintf(album_art_file, "%s.%03u.jpg", argv[i], j);
+
+				printf("%s: found artwork, writing to file %s\n", argv[i], album_art_file);
+
+				if ((album_art = fopen(album_art_file, "wb")) == NULL)
+					fprintf(stderr, "%s: failed to open file for writing\n", album_art_file);
+
+				if (fwrite(pkt.data, pkt.size, 1, album_art) != 1)
+					fprintf(stderr, "%s: failed to write to file\n", album_art_file);
+
+				fclose(album_art);
+				free(album_art_file);
+			}
+		}
+next:
+		avformat_close_input(&pFormatCtx);
+	}
+	avformat_free_context(pFormatCtx);
+
+	return EXIT_SUCCESS;
+}
+
+// vim: set syntax=c: