From fc4cd7dd43130bd62557ac730d3d083fe9277320 Mon Sep 17 00:00:00 2001
From: Martin Storsjo <martin@martin.st>
Date: Thu, 28 Feb 2013 22:57:05 +0200
Subject: [PATCH] Add an example of decoding from an ADTS file

---
 .gitignore  |   1 +
 Makefile.am |   7 +++-
 aac-dec.c   | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 119 insertions(+), 2 deletions(-)
 create mode 100644 aac-dec.c

diff --git a/.gitignore b/.gitignore
index 263e5aa..442012f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,3 +27,4 @@ missing
 stamp-h1
 aac-enc
 compile
+aac-dec
diff --git a/Makefile.am b/Makefile.am
index fe6b867..09edc9a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -39,12 +39,15 @@ libfdk_aac_la_LDFLAGS = -version-info @FDK_AAC_VERSION@ -no-undefined \
     -export-symbols $(top_srcdir)/fdk-aac.sym
 
 if EXAMPLE
-bin_PROGRAMS = aac-enc$(EXEEXT)
+bin_PROGRAMS = aac-enc$(EXEEXT) aac-dec$(EXEEXT)
 
 aac_enc_LDADD = libfdk-aac.la
 aac_enc_SOURCES = aac-enc.c wavreader.c
 
-noinst_HEADERS = wavreader.h
+aac_dec_LDADD = libfdk-aac.la
+aac_dec_SOURCES = aac-dec.c wavwriter.c
+
+noinst_HEADERS = wavreader.h wavwriter.h
 endif
 
 AACDEC_SRC = \
diff --git a/aac-dec.c b/aac-dec.c
new file mode 100644
index 0000000..3da70a3
--- /dev/null
+++ b/aac-dec.c
@@ -0,0 +1,113 @@
+/* ------------------------------------------------------------------
+ * Copyright (C) 2013 Martin Storsjo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ * -------------------------------------------------------------------
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include "libAACdec/include/aacdecoder_lib.h"
+#include "wavwriter.h"
+
+int main(int argc, char *argv[]) {
+	const char *infile, *outfile;
+	FILE *in;
+	void *wav = NULL;
+	int output_size;
+	uint8_t *output_buf;
+	int16_t *decode_buf;
+	HANDLE_AACDECODER handle;
+	int frame_size = 0;
+	if (argc < 3) {
+		fprintf(stderr, "%s in.aac out.wav\n", argv[0]);
+		return 1;
+	}
+	infile = argv[1];
+	outfile = argv[2];
+
+	handle = aacDecoder_Open(TT_MP4_ADTS, 1);
+	in = fopen(infile, "rb");
+	if (!in) {
+		perror(infile);
+		return 1;
+	}
+
+	output_size = 8*2*2048;
+	output_buf = (uint8_t*) malloc(output_size);
+	decode_buf = (int16_t*) malloc(output_size);
+
+	while (1) {
+		uint8_t packet[10240], *ptr = packet;
+		int n, i;
+		UINT valid, packet_size;
+		AAC_DECODER_ERROR err;
+		n = fread(packet, 1, 7, in);
+		if (n != 7)
+			break;
+		if (packet[0] != 0xff || (packet[1] & 0xf0) != 0xf0) {
+			fprintf(stderr, "Not an ADTS packet\n");
+			break;
+		}
+		packet_size = ((packet[3] & 0x03) << 11) | (packet[4] << 3) | (packet[5] >> 5);
+		n = fread(packet + 7, 1, packet_size - 7, in);
+		if (n != packet_size - 7) {
+			fprintf(stderr, "Partial packet\n");
+			break;
+		}
+		valid = packet_size;
+		err = aacDecoder_Fill(handle, &ptr, &packet_size, &valid);
+		if (err != AAC_DEC_OK) {
+			fprintf(stderr, "Fill failed: %x\n", err);
+			break;
+		}
+		err = aacDecoder_DecodeFrame(handle, decode_buf, output_size / sizeof(INT_PCM), 0);
+		if (err == AAC_DEC_NOT_ENOUGH_BITS)
+			continue;
+		if (err != AAC_DEC_OK) {
+			fprintf(stderr, "Decode failed: %x\n", err);
+			continue;
+		}
+		if (!wav) {
+			CStreamInfo *info = aacDecoder_GetStreamInfo(handle);
+			if (!info || info->sampleRate <= 0) {
+				fprintf(stderr, "No stream info\n");
+				break;
+			}
+			frame_size = info->frameSize * info->numChannels;
+			// Note, this probably doesn't return channels > 2 in the right order for wav
+			wav = wav_write_open(outfile, info->sampleRate, 16, info->numChannels);
+			if (!wav) {
+				perror(outfile);
+				break;
+			}
+		}
+		for (i = 0; i < frame_size; i++) {
+			uint8_t* out = &output_buf[2*i];
+			out[0] = decode_buf[i] & 0xff;
+			out[1] = decode_buf[i] >> 8;
+		}
+		wav_write_data(wav, output_buf, 2*frame_size);
+	}
+	free(output_buf);
+	free(decode_buf);
+	fclose(in);
+	if (wav)
+		wav_write_close(wav);
+	aacDecoder_Close(handle);
+	return 0;
+}
+