ffmpeg.c

ffmpeg源码分析

/*
 * FFmpeg main
 * Copyright (c) 2000-2003 Fabrice Bellard
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#define HAVE_AV_CONFIG_H
#include <limits.h>
#include "avformat.h"
#include "framehook.h"
#include "dsputil.h"
#include "opt.h"

#ifndef CONFIG_WIN32
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <termios.h>
#include <sys/resource.h>
#include <signal.h>
#endif
#ifdef CONFIG_OS2
#include <sys/types.h>
#include <sys/select.h>
#include <stdlib.h>
#endif
#undef time //needed because HAVE_AV_CONFIG_H is defined on top
#include <time.h>

#include "cmdutils.h"

#undef NDEBUG
#include <assert.h>

#if !defined(INFINITY) && defined(HUGE_VAL)
#define INFINITY HUGE_VAL
#endif

/* select an input stream for an output stream */
typedef struct AVStreamMap {
    int file_index;
    int stream_index;
    int sync_file_index;
    int sync_stream_index;
} AVStreamMap;

/** select an input file for an output file */
typedef struct AVMetaDataMap {
    int out_file;
    int in_file;
} AVMetaDataMap;

extern const OptionDef options[];

static void show_help(void);
static void show_license(void);
static int opt_default(const char *opt, const char *arg);

#define MAX_FILES 20

static AVFormatContext *input_files[MAX_FILES];
static int64_t input_files_ts_offset[MAX_FILES];
static int nb_input_files = 0;

static AVFormatContext *output_files[MAX_FILES];
static int nb_output_files = 0;

static AVStreamMap stream_maps[MAX_FILES];
static int nb_stream_maps;

static AVMetaDataMap meta_data_maps[MAX_FILES];
static int nb_meta_data_maps;

static AVInputFormat *file_iformat;
static AVOutputFormat *file_oformat;
static AVImageFormat *image_format;
static int frame_width  = 0;
static int frame_height = 0;
static float frame_aspect_ratio = 0;
static enum PixelFormat frame_pix_fmt = PIX_FMT_NONE;
static int frame_padtop  = 0;
static int frame_padbottom = 0;
static int frame_padleft  = 0;
static int frame_padright = 0;
static int padcolor[3] = {16,128,128}; /* default to black */
static int frame_topBand  = 0;
static int frame_bottomBand = 0;
static int frame_leftBand  = 0;
static int frame_rightBand = 0;
static int max_frames[4] = {INT_MAX, INT_MAX, INT_MAX, INT_MAX};
static int frame_rate = 25;
static int frame_rate_base = 1;
static int video_bit_rate = 200*1000;
static int video_bit_rate_tolerance = 4000*1000;
static float video_qscale = 0;
static int video_qmin = 2;
static int video_qmax = 31;
static int video_lmin = 2*FF_QP2LAMBDA;
static int video_lmax = 31*FF_QP2LAMBDA;
static int video_mb_lmin = 2*FF_QP2LAMBDA;
static int video_mb_lmax = 31*FF_QP2LAMBDA;
static int video_qdiff = 3;
static float video_qblur = 0.5;
static float video_qsquish = 0.0;
static float video_qcomp = 0.5;
static uint16_t *intra_matrix = NULL;
static uint16_t *inter_matrix = NULL;
#if 0 //experimental, (can be removed)
static float video_rc_qsquish=1.0;
static float video_rc_qmod_amp=0;
static int video_rc_qmod_freq=0;
#endif
static char *video_rc_override_string=NULL;
static char *video_rc_eq="tex^qComp";
static int video_rc_buffer_size=0;
static float video_rc_buffer_aggressivity=1.0;
static int video_rc_max_rate=0;
static int video_rc_min_rate=0;
static float video_rc_initial_cplx=0;
static float video_b_qfactor = 1.25;
static float video_b_qoffset = 1.25;
static float video_i_qfactor = -0.8;
static float video_i_qoffset = 0.0;
static int video_intra_quant_bias= FF_DEFAULT_QUANT_BIAS;
static int video_inter_quant_bias= FF_DEFAULT_QUANT_BIAS;
static int me_method = ME_EPZS;
static int video_disable = 0;
static int video_discard = 0;
static int video_codec_id = CODEC_ID_NONE;
static int video_codec_tag = 0;
static int same_quality = 0;
static int b_frames = 0;
static int pre_me = 0;
static int do_deinterlace = 0;
static int workaround_bugs = FF_BUG_AUTODETECT;
static int packet_size = 0;
static int error_rate = 0;
static int strict = 0;
static int top_field_first = -1;
static int sc_threshold = 0;
static int me_threshold = 0;
static int mb_threshold = 0;
static int intra_dc_precision = 8;
static int me_penalty_compensation= 256;
static int frame_skip_threshold= 0;
static int frame_skip_factor= 0;
static int frame_skip_exp= 0;
extern int loop_input; /* currently a hack */
static int loop_output = AVFMT_NOOUTPUTLOOP;
static int genpts = 0;
static int qp_hist = 0;

static int gop_size = 12;
static int intra_only = 0;
static int audio_sample_rate = 44100;
static int audio_bit_rate = 64000;
#define QSCALE_NONE -99999
static float audio_qscale = QSCALE_NONE;
static int audio_disable = 0;
static int audio_channels = 1;
static int audio_codec_id = CODEC_ID_NONE;
static int audio_codec_tag = 0;
static char *audio_language = NULL;

static int subtitle_codec_id = CODEC_ID_NONE;
static char *subtitle_language = NULL;

static int mux_rate= 0;
static int mux_packet_size= 0;
static float mux_preload= 0.5;
static float mux_max_delay= 0.7;

static int64_t recording_time = 0;
static int64_t start_time = 0;
static int64_t rec_timestamp = 0;
static int64_t input_ts_offset = 0;
static int file_overwrite = 0;
static char *str_title = NULL;
static char *str_author = NULL;
static char *str_copyright = NULL;
static char *str_comment = NULL;
static int do_benchmark = 0;
static int do_hex_dump = 0;
static int do_pkt_dump = 0;
static int do_psnr = 0;
static int do_vstats = 0;
static int do_pass = 0;
static char *pass_logfilename = NULL;
static int audio_stream_copy = 0;
static int video_stream_copy = 0;
static int subtitle_stream_copy = 0;
static int video_sync_method= 1;
static int audio_sync_method= 0;
static int copy_ts= 0;
static int opt_shortest = 0; //
static int video_global_header = 0;

static int rate_emu = 0;

#ifdef CONFIG_BKTR
static char *video_grab_format = "bktr";
#else
#ifdef CONFIG_VIDEO4LINUX2
static char *video_grab_format = "video4linux2";
#else
static char *video_grab_format = "video4linux";
#endif
#endif
static char *video_device = NULL;
static char *grab_device = NULL;
static int  video_channel = 0;
static char *video_standard = "ntsc";

static char *audio_grab_format = "audio_device";
static char *audio_device = NULL;
static int audio_volume = 256;

static int using_stdin = 0;
static int using_vhook = 0;
static int verbose = 1;
static int thread_count= 1;
static int q_pressed = 0;
static int me_range = 0;
static int64_t video_size = 0;
static int64_t audio_size = 0;
static int64_t extra_size = 0;
static int nb_frames_dup = 0;
static int nb_frames_drop = 0;
static int input_sync;
static int limit_filesize = 0; //

static int pgmyuv_compatibility_hack=0;
static int dts_delta_threshold = 10;

const char **opt_names=NULL;
int opt_name_count=0;
AVCodecContext *avctx_opts;


#define DEFAULT_PASS_LOGFILENAME "ffmpeg2pass"

struct AVInputStream;

typedef struct AVOutputStream {
    int file_index;          /* file index */
    int index;               /* stream index in the output file */
    int source_index;        /* AVInputStream index */
    AVStream *st;            /* stream in the output file */
    int encoding_needed;     /* true if encoding needed for this stream */
    int frame_number;
    /* input pts and corresponding output pts
       for A/V sync */
    //double sync_ipts;        /* dts from the AVPacket of the demuxer in second units */
    struct AVInputStream *sync_ist; /* input stream to sync against */
    int64_t sync_opts;       /* output frame counter, could be changed to some true timestamp */ //FIXME look at frame_number
    /* video only */
    int video_resample;      /* video_resample and video_crop are mutually exclusive */
    AVFrame pict_tmp;      /* temporary image for resampling */
    ImgReSampleContext *img_resample_ctx; /* for image resampling */

    int video_crop;          /* video_resample and video_crop are mutually exclusive */
    int topBand;             /* cropping area sizes */
    int leftBand;

    int video_pad;           /* video_resample and video_pad are mutually exclusive */
    int padtop;              /* padding area sizes */
    int padbottom;
    int padleft;
    int padright;

    /* audio only */
    int audio_resample;
    ReSampleContext *resample; /* for audio resampling */
    FifoBuffer fifo;     /* for compression: one audio fifo per codec */
    FILE *logfile;
} AVOutputStream;

typedef struct AVInputStream {
    int file_index;
    int index;
    AVStream *st;
    int discard;             /* true if stream data should be discarded */
    int decoding_needed;     /* true if the packets must be decoded in 'raw_fifo' */
    int64_t sample_index;      /* current sample */

    int64_t       start;     /* time when read started */
    unsigned long frame;     /* current frame */
    int64_t       next_pts;  /* synthetic pts for cases where pkt.pts
                                is not defined */
    int64_t       pts;       /* current pts */
    int is_start;            /* is 1 at the start and after a discontinuity */
} AVInputStream;

typedef struct AVInputFile {
    int eof_reached;      /* true if eof reached */
    int ist_index;        /* index of first stream in ist_table */
    int buffer_size;      /* current total buffer size */
    int buffer_size_max;  /* buffer size at which we consider we can stop
                             buffering */
    int nb_streams;       /* nb streams we are aware of */
} AVInputFile;

#ifndef CONFIG_WIN32

/* init terminal so that we can grab keys */
static struct termios oldtty;

static void term_exit(void)
{
    tcsetattr (0, TCSANOW, &oldtty);
}

static volatile sig_atomic_t received_sigterm = 0;

static void
sigterm_handler(int sig)
{
    received_sigterm = sig;
    term_exit();
}

static void term_init(void)
{
    struct termios tty;

    tcgetattr (0, &tty);
    oldtty = tty;

    tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
                          |INLCR|IGNCR|ICRNL|IXON);
    tty.c_oflag |= OPOST;
    tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
    tty.c_cflag &= ~(CSIZE|PARENB);
    tty.c_cflag |= CS8;
    tty.c_cc[VMIN] = 1;
    tty.c_cc[VTIME] = 0;

    tcsetattr (0, TCSANOW, &tty);

    signal(SIGINT , sigterm_handler); /* Interrupt (ANSI).  */
    signal(SIGQUIT, sigterm_handler); /* Quit (POSIX).  */
    signal(SIGTERM, sigterm_handler); /* Termination (ANSI).  */
    /*
    register a function to be called at normal program termination
    */