gxfenc.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

/*
 * GXF muxer.
 * Copyright (c) 2006 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>.
 *
 * 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
 */

#include "avformat.h"
#include "gxf.h"
#include "riff.h"
#include "fifo.h"

#define GXF_AUDIO_PACKET_SIZE 65536

typedef struct GXFStreamContext {
    AVCodecContext *codec;
    AVFifoBuffer audio_buffer;
    uint32_t track_type;
    uint32_t sample_size;
    uint32_t sample_rate;
    uint16_t media_type;
    uint16_t media_info;
    uint8_t index;
    int frame_rate_index;
    int lines_index;
    int fields;
    int iframes;
    int pframes;
    int bframes;
    int p_per_gop;
    int b_per_gop;
    int first_gop_closed;
    int64_t current_dts;
    int dts_delay;
} GXFStreamContext;

typedef struct GXFContext {
    uint32_t nb_frames;
    uint32_t material_flags;
    uint16_t audio_tracks;
    uint16_t mpeg_tracks;
    int64_t creation_time;
    uint32_t umf_start_offset;
    uint32_t umf_track_offset;
    uint32_t umf_media_offset;
    uint32_t umf_user_data_offset;
    uint32_t umf_user_data_size;
    uint32_t umf_length;
    uint16_t umf_track_size;
    uint16_t umf_media_size;
    int audio_written;
    int sample_rate;
    int flags;
    AVFormatContext *fc;
    GXFStreamContext streams[48];
} GXFContext;

typedef struct GXF_Lines {
    int height;
    int index;
} GXF_Lines;


/* FIXME check if it is relevant */
static const GXF_Lines gxf_lines_tab[] = {
    { 480,  1 }, /* NTSC */
    { 512,  1 }, /* NTSC + VBI */
    { 576,  2 }, /* PAL */
    { 608,  2 }, /* PAL + VBI */
    { 1080, 4 },
    { 720,  6 },
};

static const AVCodecTag gxf_media_types[] = {
    { CODEC_ID_MJPEG     ,   3 }, /* NTSC */
    { CODEC_ID_MJPEG     ,   4 }, /* PAL */
    { CODEC_ID_PCM_S24LE ,   9 },
    { CODEC_ID_PCM_S16LE ,  10 },
    { CODEC_ID_MPEG2VIDEO,  11 }, /* NTSC */
    { CODEC_ID_MPEG2VIDEO,  12 }, /* PAL */
    { CODEC_ID_DVVIDEO   ,  13 }, /* NTSC */
    { CODEC_ID_DVVIDEO   ,  14 }, /* PAL */
    { CODEC_ID_DVVIDEO   ,  15 }, /* 50M NTSC */
    { CODEC_ID_DVVIDEO   ,  16 }, /* 50M PAL */
    { CODEC_ID_AC3       ,  17 },
    //{ CODEC_ID_NONE,  ,   18 }, /* Non compressed 24 bit audio */
    { CODEC_ID_MPEG2VIDEO,  20 }, /* MPEG HD */
    { CODEC_ID_MPEG1VIDEO,  22 }, /* NTSC */
    { CODEC_ID_MPEG1VIDEO,  23 }, /* PAL */
    { 0, 0 },
};

#define SERVER_PATH "/space/"
#define ES_NAME_PATTERN "ES."

static int gxf_find_lines_index(GXFStreamContext *ctx)
{
    int i;

    for (i = 0; i < 6; ++i) {
        if (ctx->codec->height == gxf_lines_tab[i].height) {
            ctx->lines_index = gxf_lines_tab[i].index;
            return 0;
        }
    }
    return -1;
}

static void gxf_write_padding(ByteIOContext *pb, offset_t to_pad)
{
    for (; to_pad > 0; to_pad--) {
        put_byte(pb, 0);
    }
}

static offset_t updatePacketSize(ByteIOContext *pb, offset_t pos)
{
    offset_t curpos;
    int size;

    size = url_ftell(pb) - pos;
    if (size % 4) {
        gxf_write_padding(pb, 4 - size % 4);
        size = url_ftell(pb) - pos;
    }
    curpos = url_ftell(pb);
    url_fseek(pb, pos + 6, SEEK_SET);
    put_be32(pb, size);
    url_fseek(pb, curpos, SEEK_SET);
    return curpos - pos;
}

static offset_t updateSize(ByteIOContext *pb, offset_t pos)
{
    offset_t curpos;

    curpos = url_ftell(pb);
    url_fseek(pb, pos, SEEK_SET);
    put_be16(pb, curpos - pos - 2);
    url_fseek(pb, curpos, SEEK_SET);
    return curpos - pos;
}

static void gxf_write_packet_header(ByteIOContext *pb, pkt_type_t type)
{
    put_be32(pb, 0); /* packet leader for synchro */
    put_byte(pb, 1);
    put_byte(pb, type); /* map packet */
    put_be32(pb, 0); /* size */
    put_be32(pb, 0); /* reserved */
    put_byte(pb, 0xE1); /* trailer 1 */
    put_byte(pb, 0xE2); /* trailer 2 */
}

static int gxf_write_mpeg_auxiliary(ByteIOContext *pb, GXFStreamContext *ctx)
{
    char buffer[1024];
    int size;

    if (ctx->iframes) {
        ctx->p_per_gop = ctx->pframes / ctx->iframes;
        if (ctx->pframes % ctx->iframes)
            ctx->p_per_gop++;
        if (ctx->pframes)
            ctx->b_per_gop = ctx->bframes / ctx->pframes;
        if (ctx->p_per_gop > 9)
            ctx->p_per_gop = 9; /* ensure value won't take more than one char */
        if (ctx->b_per_gop > 9)
            ctx->b_per_gop = 9; /* ensure value won't take more than one char */
    }
    size = snprintf(buffer, 1024, "Ver 1\nBr %.6f\nIpg 1\nPpi %d\nBpiop %d\n"
                    "Pix 0\nCf %d\nCg %d\nSl 7\nnl16 %d\nVi 1\nf1 1\n",
                    (float)ctx->codec->bit_rate, ctx->p_per_gop, ctx->b_per_gop,
                    ctx->codec->pix_fmt == PIX_FMT_YUV422P ? 2 : 1, ctx->first_gop_closed == 1,
                    ctx->codec->height / 16);
    put_byte(pb, TRACK_MPG_AUX);
    put_byte(pb, size + 1);
    put_buffer(pb, (uint8_t *)buffer, size + 1);
    return size + 3;
}

static int gxf_write_timecode_auxiliary(ByteIOContext *pb, GXFStreamContext *ctx)
{
    /* FIXME implement that */
    put_byte(pb, 0); /* fields */
    put_byte(pb, 0);  /* seconds */
    put_byte(pb, 0); /* minutes */
    put_byte(pb, 0); /* flags + hours */
    /* reserved */
    put_be32(pb, 0);
    return 8;
}

static int gxf_write_track_description(ByteIOContext *pb, GXFStreamContext *stream)
{
    offset_t pos;

    /* track description section */
    put_byte(pb, stream->media_type + 0x80);
    put_byte(pb, stream->index + 0xC0);

    pos = url_ftell(pb);
    put_be16(pb, 0); /* size */

    /* media file name */
    put_byte(pb, TRACK_NAME);
    put_byte(pb, strlen(ES_NAME_PATTERN) + 3);
    put_tag(pb, ES_NAME_PATTERN);
    put_be16(pb, stream->media_info);
    put_byte(pb, 0);

    if (stream->codec->codec_id != CODEC_ID_MPEG2VIDEO) {
        /* auxiliary information */
        put_byte(pb, TRACK_AUX);
        put_byte(pb, 8);
        if (stream->codec->codec_id == CODEC_ID_NONE)
            gxf_write_timecode_auxiliary(pb, stream);
        else
            put_le64(pb, 0);
    }

    /* file system version */
    put_byte(pb, TRACK_VER);
    put_byte(pb, 4);
    put_be32(pb, 0);

    if (stream->codec->codec_id == CODEC_ID_MPEG2VIDEO)
        gxf_write_mpeg_auxiliary(pb, stream);

    /* frame rate */
    put_byte(pb, TRACK_FPS);
    put_byte(pb, 4);
    put_be32(pb, stream->frame_rate_index);

    /* lines per frame */
    put_byte(pb, TRACK_LINES);
    put_byte(pb, 4);
    put_be32(pb, stream->lines_index);

    /* fields per frame */
    put_byte(pb, TRACK_FPF);
    put_byte(pb, 4);
    put_be32(pb, stream->fields);

    return updateSize(pb, pos);
}

static int gxf_write_material_data_section(ByteIOContext *pb, GXFContext *ctx)
{
    offset_t pos;
    const char *filename = strrchr(ctx->fc->filename, '/');

    pos = url_ftell(pb);
    put_be16(pb, 0); /* size */

    /* name */
    if (filename)
        filename++;
    else
        filename = ctx->fc->filename;
    put_byte(pb, MAT_NAME);
    put_byte(pb, strlen(SERVER_PATH) + strlen(filename) + 1);
    put_tag(pb, SERVER_PATH);
    put_tag(pb, filename);
    put_byte(pb, 0);

    /* first field */
    put_byte(pb, MAT_FIRST_FIELD);
    put_byte(pb, 4);
    put_be32(pb, 0);

    /* last field */
    put_byte(pb, MAT_LAST_FIELD);
    put_byte(pb, 4);
    put_be32(pb, ctx->nb_frames);

    /* reserved */
    put_byte(pb, MAT_MARK_IN);
    put_byte(pb, 4);
    put_be32(pb, 0);

    put_byte(pb, MAT_MARK_OUT);
    put_byte(pb, 4);
    put_be32(pb, ctx->nb_frames);

    /* estimated size */
    put_byte(pb, MAT_SIZE);
    put_byte(pb, 4);
    put_be32(pb, url_fsize(pb) / 1024);

    return updateSize(pb, pos);
}

static int gxf_write_track_description_section(ByteIOContext *pb, GXFContext *ctx)
{
    offset_t pos;
    int i;

    pos = url_ftell(pb);
    put_be16(pb, 0); /* size */
    for (i = 0; i < ctx->fc->nb_streams; ++i)
        gxf_write_track_description(pb, &ctx->streams[i]);
    return updateSize(pb, pos);
}

static int gxf_write_map_packet(ByteIOContext *pb, GXFContext *ctx)
{
    offset_t pos = url_ftell(pb);

    gxf_write_packet_header(pb, PKT_MAP);

    /* preamble */
    put_byte(pb, 0xE0); /* version */
    put_byte(pb, 0xFF); /* reserved */

    gxf_write_material_data_section(pb, ctx);
    gxf_write_track_description_section(pb, ctx);

    return updatePacketSize(pb, pos);
}

#if 0
static int gxf_write_flt_packet(ByteIOContext *pb, GXFContext *ctx)
{
    offset_t pos = url_ftell(pb);
    int i;

    gxf_write_packet_header(pb, PKT_FLT);

    put_le32(pb, 1000); /* number of fields */
    put_le32(pb, 0); /* number of active flt entries */

    for (i = 0; i < 1000; ++i) {
        put_le32(pb, 0);
    }
    return updatePacketSize(pb, pos);
}
#endif

static int gxf_write_umf_material_description(ByteIOContext *pb, GXFContext *ctx)
{
    put_le32(pb, ctx->flags);
    put_le32(pb, ctx->nb_frames); /* length of the longest track */
    put_le32(pb, ctx->nb_frames); /* length of the shortest track */
    put_le32(pb, 0); /* mark in */
    put_le32(pb, ctx->nb_frames); /* mark out */
    put_le32(pb, 0); /* timecode mark in */
    put_le32(pb, ctx->nb_frames); /* timecode mark out */
    put_le64(pb, ctx->fc->timestamp); /* modification time */
    put_le64(pb, ctx->fc->timestamp); /* creation time */
    put_le16(pb, 0); /* reserved */
    put_le16(pb, 0); /* reserved */
    put_le16(pb, ctx->audio_tracks);
    put_le16(pb, 0); /* timecode track count */
    put_le16(pb, 0); /* reserved */
    put_le16(pb, ctx->mpeg_tracks);
    return 48;
}

static int gxf_write_umf_payload(ByteIOContext *pb, GXFContext *ctx)
{
    put_le32(pb, ctx->umf_length); /* total length of the umf data */
    put_le32(pb, 3); /* version */
    put_le32(pb, ctx->fc->nb_streams);
    put_le32(pb, ctx->umf_track_offset); /* umf track section offset */
    put_le32(pb, ctx->umf_track_size);
    put_le32(pb, ctx->fc->nb_streams);
    put_le32(pb, ctx->umf_media_offset);
    put_le32(pb, ctx->umf_media_size);
    put_le32(pb, ctx->umf_user_data_offset); /* user data offset */
    put_le32(pb, ctx->umf_user_data_size); /* user data size */
    put_le32(pb, 0); /* reserved */
    put_le32(pb, 0); /* reserved */
    return 48;
}

static int gxf_write_umf_track_description(ByteIOContext *pb, GXFContext *ctx)
{
    offset_t pos = url_ftell(pb);
    int tracks[255]={0};
    int i;

    ctx->umf_track_offset = pos - ctx->umf_start_offset;
    for (i = 0; i < ctx->fc->nb_streams; ++i) {
        AVStream *st = ctx->fc->streams[i];
        GXFStreamContext *sc = &ctx->streams[i];
        int id = 0;

        switch (st->codec->codec_id) {
        case CODEC_ID_MPEG1VIDEO: id= 'L'; break;
        case CODEC_ID_MPEG2VIDEO: id= 'M'; break;
        case CODEC_ID_PCM_S16LE:  id= 'A'; break;
        case CODEC_ID_DVVIDEO:    id= sc->track_type == 6 ? 'E' : 'D'; break;
        case CODEC_ID_MJPEG:      id= 'V'; break;
        default:                  break;
        }
        sc->media_info= id << 8;
        /* FIXME first 10 audio tracks are 0 to 9 next 22 are A to V */
        sc->media_info |= '0' + (tracks[id]++);
        put_le16(pb, sc->media_info);
        put_le16(pb, 1);