/*
* Copyright (c) 2013-2018 Andreas Unterweger
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Simple audio converter
*
* @example transcode_aac.c
* Convert an input audio file to AAC in an MP4 container using FFmpeg.
* Formats other than MP4 are supported based on the output file extension.
* @author Andreas Unterweger (dustsigns@gmail.com)
*/
#include <stdio.h>
#include "libavformat/avformat.h"
#include "libavformat/avio.h"
#include "libavcodec/avcodec.h"
#include "libavutil/audio_fifo.h"
#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/frame.h"
#include "libavutil/opt.h"
#include "libswresample/swresample.h"
/* The output bit rate in bit/s */
#define OUTPUT_BIT_RATE 96000
/* The number of output channels */
#define OUTPUT_CHANNELS 2
/**
* Open an input file and the required decoder.
* @param filename File to be opened
* @param[out] input_format_context Format context of opened file
* @param[out] input_codec_context Codec context of opened file
* @return Error code (0 if successful)
*/
static int open_input_file(const char *filename,
AVFormatContext **input_format_context,
AVCodecContext **input_codec_context)
{
AVCodecContext *avctx;
AVCodec *input_codec;
int error;
/* Open the input file to read from it. */
if ((error = avformat_open_input(input_format_context, filename, NULL,
NULL)) < 0) {
fprintf(stderr, "Could not open input file '%s' (error '%s')\n",
filename, av_err2str(error));
*input_format_context = NULL;
return error;
}
/* Get information on the input file (number of streams etc.). */
if ((error = avformat_find_stream_info(*input_format_context, NULL)) < 0) {
fprintf(stderr, "Could not open find stream info (error '%s')\n",
av_err2str(error));
avformat_close_input(input_format_context);
return error;
}
/* Make sure that there is only one stream in the input file. */
if ((*input_format_context)->nb_streams != 1) {
fprintf(stderr, "Expected one audio input stream, but found %d\n",
(*input_format_context)->nb_streams);
avformat_close_input(input_format_context);
return AVERROR_EXIT;
}
/* Find a decoder for the audio stream. */
if (!(input_codec = avcodec_find_decoder((*input_format_context)->streams[0]->codecpar->codec_id))) {
fprintf(stderr, "Could not find input codec\n");
avformat_close_input(input_format_context);
return AVERROR_EXIT;
}
/* Allocate a new decoding context. */
avctx = avcodec_alloc_context3(input_codec);
if (!avctx) {
fprintf(stderr, "Could not allocate a decoding context\n");
avformat_close_input(input_format_context);
return AVERROR(ENOMEM);
}
/* Initialize the stream parameters with demuxer information. */
error = avcodec_parameters_to_context(avctx, (*input_format_context)->streams[0]->codecpar);
if (error < 0) {
avformat_close_input(input_format_context);
avcodec_free_context(&avctx);
return error;
}
/* Open the decoder for the audio stream to use it later. */
if ((error = avcodec_open2(avctx, input_codec, NULL)) < 0) {
fprintf(stderr, "Could not open input codec (error '%s')\n",
av_err2str(error));
avcodec_free_context(&avctx);
avformat_close_input(input_format_context);
return error;
}
/* Save the decoder context for easier access later. */
*input_codec_context = avctx;
return 0;
}
/**
* Open an output file and the required encoder.
* Also set some basic encoder parameters.
* Some of these parameters are based on the input file's parameters.
* @param filename File to be opened
* @param input_codec_context Codec context of input file
* @param[out] output_format_context Format context of output file
* @param[out] output_codec_context Codec context of output file
* @return Error code (0 if successful)
*/
static int open_output_file(const char *filename,
AVCodecContext *input_codec_context,
AVFormatContext **output_format_context,
AVCodecContext **output_codec_context)
{
AVCodecContext *avctx = NULL;
AVIOContext *output_io_context = NULL;
AVStream *stream = NULL;
AVCodec *output_codec = NULL;
int error;
/* Open the output file to write to it. */
if ((error = avio_open(&output_io_context, filename,
AVIO_FLAG_WRITE)) < 0) {
fprintf(stderr, "Could not open output file '%s' (error '%s')\n",
filename, av_err2str(error));
return error;
}
/* Create a new format context for the output container format. */
if (!(*output_format_context = avformat_alloc_context())) {
fprintf(stderr, "Could not allocate output format context\n");
return AVERROR(ENOMEM);
}
/* Associate the output file (pointer) with the container format context. */
(*output_format_context)->pb = output_io_context;
/* Guess the desired container format based on the file extension. */
if (!((*output_format_context)->oformat = av_guess_format(NULL, filename,
NULL))) {
fprintf(stderr, "Could not find output file format\n");
goto cleanup;
}
if (!((*output_format_context)->url = av_strdup(filename))) {
fprintf(stderr, "Could not allocate url.\n");
error = AVERROR(ENOMEM);
goto cleanup;
}
/* Find the encoder to be used by its name. */
if (!(output_codec = avcodec_find_encoder(AV_CODEC_ID_AAC))) {
fprintf(stderr, "Could not find an AAC encoder.\n");
goto cleanup;
}
/* Create a new audio stream in the output file container. */
if (!(stream = avformat_new_stream(*output_format_context, NULL))) {
fprintf(stderr, "Could not create new stream\n");
error = AVERROR(ENOMEM);
goto cleanup;
}
avctx = avcodec_alloc_context3(output_codec);
if (!avctx) {
fprintf(stderr, "Could not allocate an encoding context\n");
error = AVERROR(ENOMEM);
goto cleanup;
}
/* Set the basic encoder parameters.
* The input file's sample rate is used to avoid a sample rate conversion. */
avctx->channels = OUTPUT_CHANNELS;
avctx->channel_layout = av_get_default_channel_layout(OUTPUT_CHANNELS);
avctx->sample_rate = input_codec_context->sample_rate;
avctx->sample_fmt = output_codec->sample_fmts[0];
avctx->bit_rate = OUTPUT_BIT_RATE;
/* Allow the use of the experimental AAC encoder. */
avctx->strict_std_compliance = FF_COMPLIANCE_EXPERIMENTAL;
/* Set the sample rate for the container. */
stream->time_base.den = input_codec_context->sample_rate;
stream->time_base.num = 1;
/* Some container formats (like MP4) require global headers to be present.
* Mark the encoder so that it behaves accordingly.
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收起资源包目录
ffmpeg 4.4.1 android静态库 x86 v7a v8a架构 (468个子文件)
libavcodec.a 100.13MB
libavcodec.a 88.11MB
libavcodec.a 87.11MB
libavformat.a 46.15MB
libavformat.a 42.28MB
libavformat.a 41.73MB
libavfilter.a 21.08MB
libavfilter.a 18.42MB
libavfilter.a 17.31MB
libswscale.a 3.35MB
libswscale.a 2.66MB
libswscale.a 2.25MB
libavutil.a 2.12MB
libavutil.a 2.11MB
libavutil.a 2.02MB
libavdevice.a 973KB
libavdevice.a 900KB
libavdevice.a 893KB
libswresample.a 422KB
libswresample.a 361KB
libswresample.a 352KB
libpostproc.a 291KB
libpostproc.a 127KB
libpostproc.a 98KB
transcode_aac.c 34KB
transcode_aac.c 34KB
transcode_aac.c 34KB
transcoding.c 22KB
transcoding.c 22KB
transcoding.c 22KB
muxing.c 21KB
muxing.c 21KB
muxing.c 21KB
demuxing_decoding.c 14KB
demuxing_decoding.c 14KB
demuxing_decoding.c 14KB
filter_audio.c 12KB
filter_audio.c 12KB
filter_audio.c 12KB
filtering_audio.c 10KB
filtering_audio.c 10KB
filtering_audio.c 10KB
vaapi_transcode.c 10KB
vaapi_transcode.c 10KB
vaapi_transcode.c 10KB
filtering_video.c 9KB
filtering_video.c 9KB
filtering_video.c 9KB
qsvdec.c 8KB
qsvdec.c 8KB
qsvdec.c 8KB
resampling_audio.c 8KB
resampling_audio.c 8KB
resampling_audio.c 8KB
hw_decode.c 8KB
hw_decode.c 8KB
hw_decode.c 8KB
vaapi_encode.c 7KB
vaapi_encode.c 7KB
vaapi_encode.c 7KB
encode_audio.c 6KB
encode_audio.c 6KB
encode_audio.c 6KB
remuxing.c 6KB
remuxing.c 6KB
remuxing.c 6KB
extract_mvs.c 6KB
extract_mvs.c 6KB
extract_mvs.c 6KB
avio_dir_cmd.c 5KB
avio_dir_cmd.c 5KB
avio_dir_cmd.c 5KB
encode_video.c 5KB
encode_video.c 5KB
encode_video.c 5KB
decode_audio.c 5KB
decode_audio.c 5KB
decode_audio.c 5KB
decode_video.c 5KB
decode_video.c 5KB
decode_video.c 5KB
http_multiclient.c 5KB
http_multiclient.c 5KB
http_multiclient.c 5KB
scaling_video.c 5KB
scaling_video.c 5KB
scaling_video.c 5KB
avio_reading.c 4KB
avio_reading.c 4KB
avio_reading.c 4KB
metadata.c 2KB
metadata.c 2KB
metadata.c 2KB
avcodec.h 209KB
avcodec.h 209KB
avcodec.h 209KB
avformat.h 116KB
avformat.h 116KB
avformat.h 116KB
avfilter.h 41KB
共 468 条
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