From 1d9346e267c0fd4b727cd2e5d319cd43c4a0e462 Mon Sep 17 00:00:00 2001 From: Martin Storsjo Date: Fri, 1 Mar 2013 11:31:43 +0200 Subject: [PATCH] Add a decoding example that uses libavformat to demux .m4a files --- Makefile.am | 8 +++ configure.ac | 9 ++++ m4a-dec.c | 139 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 156 insertions(+) create mode 100644 m4a-dec.c diff --git a/Makefile.am b/Makefile.am index 2b0d92b..10650f6 100644 --- a/Makefile.am +++ b/Makefile.am @@ -43,6 +43,14 @@ aac_dec_LDADD = libfdk-aac.la aac_dec_SOURCES = aac-dec.c wavwriter.c noinst_HEADERS = wavreader.h wavwriter.h + +if HAVE_LIBAVFORMAT +bin_PROGRAMS += m4a-dec$(EXEEXT) + +m4a_dec_LDADD = $(libavformat_LIBS) libfdk-aac.la +m4a_dec_CFLAGS = $(libavformat_CFLAGS) +m4a_dec_SOURCES = m4a-dec.c wavwriter.c +endif endif AACDEC_SRC = \ diff --git a/configure.ac b/configure.ac index 86a9102..92f52af 100644 --- a/configure.ac +++ b/configure.ac @@ -13,8 +13,13 @@ AC_ARG_ENABLE([example], [enable example encoding program (default is no)])], [example=$enableval], [example=no]) +if test x$example = xyes; then + PKG_CHECK_MODULES([libavformat], [libavformat], [libavformat=yes], [libavformat=no]) +fi + dnl Automake conditionals to set AM_CONDITIONAL(EXAMPLE, test x$example = xyes) +AM_CONDITIONAL(HAVE_LIBAVFORMAT, test x$libavformat = xyes) dnl Checks for programs. AC_PROG_CC @@ -36,3 +41,7 @@ AC_SUBST(LIBS_PRIVATE) AC_CONFIG_FILES([Makefile fdk-aac.pc]) AC_OUTPUT + +if test x$example = xyes; then + AC_MSG_NOTICE([Found libavformat: ${libavformat}]) +fi diff --git a/m4a-dec.c b/m4a-dec.c new file mode 100644 index 0000000..8ad7b97 --- /dev/null +++ b/m4a-dec.c @@ -0,0 +1,139 @@ +/* ------------------------------------------------------------------ + * 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 +#include +#include +#include +#include "libAACdec/include/aacdecoder_lib.h" +#include "wavwriter.h" +#include + +#if LIBAVCODEC_VERSION_MAJOR < 55 +#define AV_CODEC_ID_AAC CODEC_ID_AAC +#endif + +int main(int argc, char *argv[]) { + const char *infile, *outfile; + AVFormatContext *in = NULL; + AVStream *st = NULL; + void *wav = NULL; + int output_size, ret, i; + uint8_t *output_buf; + int16_t *decode_buf; + HANDLE_AACDECODER handle; + AAC_DECODER_ERROR err; + int frame_size = 0; + if (argc < 3) { + fprintf(stderr, "%s in.m4a out.wav\n", argv[0]); + return 1; + } + infile = argv[1]; + outfile = argv[2]; + + av_register_all(); + avformat_network_init(); + ret = avformat_open_input(&in, infile, NULL, NULL); + if (ret < 0) { + char buf[100]; + av_strerror(ret, buf, sizeof(buf)); + fprintf(stderr, "%s: %s\n", infile, buf); + return 1; + } + for (i = 0; i < in->nb_streams && !st; i++) { + if (in->streams[i]->codec->codec_id == AV_CODEC_ID_AAC) + st = in->streams[i]; + } + if (!st) { + fprintf(stderr, "No AAC stream found\n"); + return 1; + } + if (!st->codec->extradata_size) { + fprintf(stderr, "No AAC ASC found\n"); + return 1; + } + handle = aacDecoder_Open(TT_MP4_RAW, 1); + err = aacDecoder_ConfigRaw(handle, &st->codec->extradata, &st->codec->extradata_size); + if (err != AAC_DEC_OK) { + fprintf(stderr, "Unable to decode the ASC\n"); + return 1; + } + + output_size = 8*2*1024; + output_buf = (uint8_t*) malloc(output_size); + decode_buf = (int16_t*) malloc(output_size); + + while (1) { + int i; + UINT valid; + AVPacket pkt = { 0 }; + int ret = av_read_frame(in, &pkt); + if (ret < 0) { + if (ret == AVERROR(EAGAIN)) + continue; + break; + } + if (pkt.stream_index != st->index) { + av_free_packet(&pkt); + continue; + } + + valid = pkt.size; + err = aacDecoder_Fill(handle, &pkt.data, &pkt.size, &valid); + if (err != AAC_DEC_OK) { + fprintf(stderr, "Fill failed: %x\n", err); + break; + } + err = aacDecoder_DecodeFrame(handle, decode_buf, output_size, 0); + av_free_packet(&pkt); + 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); + avformat_close_input(&in); + if (wav) + wav_write_close(wav); + aacDecoder_Close(handle); + return 0; +} +