PeerStreamer

/*

 * Flash Compatible Streaming Format muxer

 * Copyright (c) 2000 Fabrice Bellard

 * Copyright (c) 2003 Tinic Uro

 *

 * 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 "libavcodec/put_bits.h"

#include "avformat.h"

#include "swf.h"

static void put_swf_tag(AVFormatContext *s, int tag)

{

    SWFContext *swf = s->priv_data;

    AVIOContext *pb = s->pb;

    swf->tag_pos = avio_tell(pb);

    swf->tag = tag;

    /* reserve some room for the tag */

    if (tag & TAG_LONG) {

        avio_wl16(pb, 0);

        avio_wl32(pb, 0);

    } else {

        avio_wl16(pb, 0);

    }

}

static void put_swf_end_tag(AVFormatContext *s)

{

    SWFContext *swf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t pos;

    int tag_len, tag;

    pos = avio_tell(pb);

    tag_len = pos - swf->tag_pos - 2;

    tag = swf->tag;

    avio_seek(pb, swf->tag_pos, SEEK_SET);

    if (tag & TAG_LONG) {

        tag &= ~TAG_LONG;

        avio_wl16(pb, (tag << 6) | 0x3f);

        avio_wl32(pb, tag_len - 4);

    } else {

        assert(tag_len < 0x3f);

        avio_wl16(pb, (tag << 6) | tag_len);

    }

    avio_seek(pb, pos, SEEK_SET);

}

static inline void max_nbits(int *nbits_ptr, int val)

{

    int n;

    if (val == 0)

        return;

    val = abs(val);

    n = 1;

    while (val != 0) {

        n++;

        val >>= 1;

    }

    if (n > *nbits_ptr)

        *nbits_ptr = n;

}

static void put_swf_rect(AVIOContext *pb,

                         int xmin, int xmax, int ymin, int ymax)

{

    PutBitContext p;

    uint8_t buf[256];

    int nbits, mask;

    init_put_bits(&p, buf, sizeof(buf));

    nbits = 0;

    max_nbits(&nbits, xmin);

    max_nbits(&nbits, xmax);

    max_nbits(&nbits, ymin);

    max_nbits(&nbits, ymax);

    mask = (1 << nbits) - 1;

    /* rectangle info */

    put_bits(&p, 5, nbits);

    put_bits(&p, nbits, xmin & mask);

    put_bits(&p, nbits, xmax & mask);

    put_bits(&p, nbits, ymin & mask);

    put_bits(&p, nbits, ymax & mask);

    flush_put_bits(&p);

    avio_write(pb, buf, put_bits_ptr(&p) - p.buf);

}

static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)

{

    int nbits, mask;

    put_bits(pb, 1, 1); /* edge */

    put_bits(pb, 1, 1); /* line select */

    nbits = 2;

    max_nbits(&nbits, dx);

    max_nbits(&nbits, dy);

    mask = (1 << nbits) - 1;

    put_bits(pb, 4, nbits - 2); /* 16 bits precision */

    if (dx == 0) {

        put_bits(pb, 1, 0);

        put_bits(pb, 1, 1);

        put_bits(pb, nbits, dy & mask);

    } else if (dy == 0) {

        put_bits(pb, 1, 0);

        put_bits(pb, 1, 0);

        put_bits(pb, nbits, dx & mask);

    } else {

        put_bits(pb, 1, 1);

        put_bits(pb, nbits, dx & mask);

        put_bits(pb, nbits, dy & mask);

    }

}

#define FRAC_BITS 16

static void put_swf_matrix(AVIOContext *pb,

                           int a, int b, int c, int d, int tx, int ty)

{

    PutBitContext p;

    uint8_t buf[256];

    int nbits;

    init_put_bits(&p, buf, sizeof(buf));

    put_bits(&p, 1, 1); /* a, d present */

    nbits = 1;

    max_nbits(&nbits, a);

    max_nbits(&nbits, d);

    put_bits(&p, 5, nbits); /* nb bits */

    put_bits(&p, nbits, a);

    put_bits(&p, nbits, d);

    put_bits(&p, 1, 1); /* b, c present */

    nbits = 1;

    max_nbits(&nbits, c);

    max_nbits(&nbits, b);

    put_bits(&p, 5, nbits); /* nb bits */

    put_bits(&p, nbits, c);

    put_bits(&p, nbits, b);

    nbits = 1;

    max_nbits(&nbits, tx);

    max_nbits(&nbits, ty);

    put_bits(&p, 5, nbits); /* nb bits */

    put_bits(&p, nbits, tx);

    put_bits(&p, nbits, ty);

    flush_put_bits(&p);

    avio_write(pb, buf, put_bits_ptr(&p) - p.buf);

}

static int swf_write_header(AVFormatContext *s)

{

    SWFContext *swf = s->priv_data;

    AVIOContext *pb = s->pb;

    PutBitContext p;

    uint8_t buf1[256];

    int i, width, height, rate, rate_base;

    int version;

    swf->sound_samples = 0;

    swf->swf_frame_number = 0;

    swf->video_frame_number = 0;

    for(i=0;i<s->nb_streams;i++) {

        AVCodecContext *enc = s->streams[i]->codec;

        if (enc->codec_type == AVMEDIA_TYPE_AUDIO) {

            if (enc->codec_id == CODEC_ID_MP3) {

                if (!enc->frame_size) {

                    av_log(s, AV_LOG_ERROR, "audio frame size not set\n");

                    return -1;

                }

                swf->audio_enc = enc;

                swf->audio_fifo= av_fifo_alloc(AUDIO_FIFO_SIZE);

                if (!swf->audio_fifo)

                    return AVERROR(ENOMEM);

            } else {

                av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");

                return -1;

            }

        } else {

            if (enc->codec_id == CODEC_ID_VP6F ||

                enc->codec_id == CODEC_ID_FLV1 ||

                enc->codec_id == CODEC_ID_MJPEG) {

                swf->video_enc = enc;

            } else {

                av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");

                return -1;

            }

        }

    }

    if (!swf->video_enc) {

        /* currently, cannot work correctly if audio only */

        width = 320;

        height = 200;

        rate = 10;

        rate_base= 1;

    } else {

        width = swf->video_enc->width;

        height = swf->video_enc->height;

        rate = swf->video_enc->time_base.den;

        rate_base = swf->video_enc->time_base.num;

    }

    if (!swf->audio_enc)

        swf->samples_per_frame = (44100. * rate_base) / rate;

    else

        swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;

    avio_write(pb, "FWS", 3);

    if (!strcmp("avm2", s->oformat->name))

        version = 9;

    else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_VP6F)

        version = 8; /* version 8 and above support VP6 codec */

    else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_FLV1)

        version = 6; /* version 6 and above support FLV1 codec */

    else

        version = 4; /* version 4 for mpeg audio support */

    avio_w8(pb, version);

    avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size

                                      (will be patched if not streamed) */

    put_swf_rect(pb, 0, width * 20, 0, height * 20);

    avio_wl16(pb, (rate * 256) / rate_base); /* frame rate */

    swf->duration_pos = avio_tell(pb);

    avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */

    /* avm2/swf v9 (also v8?) files require a file attribute tag */

    if (version == 9) {

        put_swf_tag(s, TAG_FILEATTRIBUTES);

        avio_wl32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */

        put_swf_end_tag(s);

    }

    /* define a shape with the jpeg inside */

    if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_MJPEG) {

        put_swf_tag(s, TAG_DEFINESHAPE);

        avio_wl16(pb, SHAPE_ID); /* ID of shape */

        /* bounding rectangle */

        put_swf_rect(pb, 0, width, 0, height);

        /* style info */

        avio_w8(pb, 1); /* one fill style */

        avio_w8(pb, 0x41); /* clipped bitmap fill */

        avio_wl16(pb, BITMAP_ID); /* bitmap ID */

        /* position of the bitmap */

        put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,

                       0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);

        avio_w8(pb, 0); /* no line style */

        /* shape drawing */

        init_put_bits(&p, buf1, sizeof(buf1));

        put_bits(&p, 4, 1); /* one fill bit */

        put_bits(&p, 4, 0); /* zero line bit */

        put_bits(&p, 1, 0); /* not an edge */

        put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);

        put_bits(&p, 5, 1); /* nbits */

        put_bits(&p, 1, 0); /* X */

        put_bits(&p, 1, 0); /* Y */

        put_bits(&p, 1, 1); /* set fill style 1 */

        /* draw the rectangle ! */

        put_swf_line_edge(&p, width, 0);

        put_swf_line_edge(&p, 0, height);

        put_swf_line_edge(&p, -width, 0);

        put_swf_line_edge(&p, 0, -height);

        /* end of shape */

        put_bits(&p, 1, 0); /* not an edge */

        put_bits(&p, 5, 0);

        flush_put_bits(&p);

        avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);

        put_swf_end_tag(s);

    }

    if (swf->audio_enc && swf->audio_enc->codec_id == CODEC_ID_MP3) {

        int v = 0;

        /* start sound */

        put_swf_tag(s, TAG_STREAMHEAD2);

        switch(swf->audio_enc->sample_rate) {

        case 11025: v |= 1 << 2; break;

        case 22050: v |= 2 << 2; break;

        case 44100: v |= 3 << 2; break;

        default:

            /* not supported */

            av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");

            return -1;

        }

        v |= 0x02; /* 16 bit playback */

        if (swf->audio_enc->channels == 2)

            v |= 0x01; /* stereo playback */

        avio_w8(s->pb, v);

        v |= 0x20; /* mp3 compressed */

        avio_w8(s->pb, v);

        avio_wl16(s->pb, swf->samples_per_frame);  /* avg samples per frame */

        avio_wl16(s->pb, 0);

        put_swf_end_tag(s);

    }

    put_flush_packet(s->pb);

    return 0;

}

static int swf_write_video(AVFormatContext *s,

                           AVCodecContext *enc, const uint8_t *buf, int size)

{

    SWFContext *swf = s->priv_data;

    AVIOContext *pb = s->pb;

    /* Flash Player limit */

    if (swf->swf_frame_number == 16000)

        av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");

    if (enc->codec_id == CODEC_ID_VP6F ||

        enc->codec_id == CODEC_ID_FLV1) {

        if (swf->video_frame_number == 0) {

            /* create a new video object */

            put_swf_tag(s, TAG_VIDEOSTREAM);

            avio_wl16(pb, VIDEO_ID);

            swf->vframes_pos = avio_tell(pb);

            avio_wl16(pb, 15000); /* hard flash player limit */

            avio_wl16(pb, enc->width);

            avio_wl16(pb, enc->height);

            avio_w8(pb, 0);

            avio_w8(pb,ff_codec_get_tag(swf_codec_tags,enc->codec_id));

            put_swf_end_tag(s);

            /* place the video object for the first time */

            put_swf_tag(s, TAG_PLACEOBJECT2);

            avio_w8(pb, 0x36);

            avio_wl16(pb, 1);

            avio_wl16(pb, VIDEO_ID);

            put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);

            avio_wl16(pb, swf->video_frame_number);

            avio_write(pb, "video", 5);

            avio_w8(pb, 0x00);

            put_swf_end_tag(s);

        } else {

            /* mark the character for update */

            put_swf_tag(s, TAG_PLACEOBJECT2);

            avio_w8(pb, 0x11);

            avio_wl16(pb, 1);

            avio_wl16(pb, swf->video_frame_number);

            put_swf_end_tag(s);

        }

        /* set video frame data */

        put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);

        avio_wl16(pb, VIDEO_ID);

        avio_wl16(pb, swf->video_frame_number++);

        avio_write(pb, buf, size);

        put_swf_end_tag(s);

    } else if (enc->codec_id == CODEC_ID_MJPEG) {

        if (swf->swf_frame_number > 0) {

            /* remove the shape */

            put_swf_tag(s, TAG_REMOVEOBJECT);

            avio_wl16(pb, SHAPE_ID); /* shape ID */

            avio_wl16(pb, 1); /* depth */

            put_swf_end_tag(s);

            /* free the bitmap */

            put_swf_tag(s, TAG_FREECHARACTER);

            avio_wl16(pb, BITMAP_ID);

            put_swf_end_tag(s);

        }

        put_swf_tag(s, TAG_JPEG2 | TAG_LONG);

        avio_wl16(pb, BITMAP_ID); /* ID of the image */

        /* a dummy jpeg header seems to be required */

        avio_wb32(pb, 0xffd8ffd9);

        /* write the jpeg image */

        avio_write(pb, buf, size);

        put_swf_end_tag(s);

        /* draw the shape */

        put_swf_tag(s, TAG_PLACEOBJECT);

        avio_wl16(pb, SHAPE_ID); /* shape ID */

        avio_wl16(pb, 1); /* depth */

        put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);

        put_swf_end_tag(s);

    }

    swf->swf_frame_number++;

    /* streaming sound always should be placed just before showframe tags */

    if (swf->audio_enc && av_fifo_size(swf->audio_fifo)) {

        int frame_size = av_fifo_size(swf->audio_fifo);

        put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);

        avio_wl16(pb, swf->sound_samples);

        avio_wl16(pb, 0); // seek samples

        av_fifo_generic_read(swf->audio_fifo, pb, frame_size, &avio_write);

        put_swf_end_tag(s);

        /* update FIFO */

        swf->sound_samples = 0;

    }

    /* output the frame */

    put_swf_tag(s, TAG_SHOWFRAME);

    put_swf_end_tag(s);

    put_flush_packet(s->pb);

    return 0;

}

static int swf_write_audio(AVFormatContext *s,

                           AVCodecContext *enc, uint8_t *buf, int size)

{

    SWFContext *swf = s->priv_data;

    /* Flash Player limit */

    if (swf->swf_frame_number == 16000)

        av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");

    if (av_fifo_size(swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {

        av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");

        return -1;

    }

    av_fifo_generic_write(swf->audio_fifo, buf, size, NULL);

    swf->sound_samples += enc->frame_size;

    /* if audio only stream make sure we add swf frames */

    if (!swf->video_enc)

        swf_write_video(s, enc, 0, 0);

    return 0;

}

static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)

{

    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;

    if (codec->codec_type == AVMEDIA_TYPE_AUDIO)

        return swf_write_audio(s, codec, pkt->data, pkt->size);

    else

        return swf_write_video(s, codec, pkt->data, pkt->size);

}

static int swf_write_trailer(AVFormatContext *s)

{

    SWFContext *swf = s->priv_data;

    AVIOContext *pb = s->pb;

    AVCodecContext *enc, *video_enc;

    int file_size, i;

    video_enc = NULL;

    for(i=0;i<s->nb_streams;i++) {

        enc = s->streams[i]->codec;

        if (enc->codec_type == AVMEDIA_TYPE_VIDEO)

            video_enc = enc;

        else

            av_fifo_free(swf->audio_fifo);

    }

    put_swf_tag(s, TAG_END);

    put_swf_end_tag(s);

    put_flush_packet(s->pb);

    /* patch file size and number of frames if not streamed */

    if (!url_is_streamed(s->pb) && video_enc) {

        file_size = avio_tell(pb);

        avio_seek(pb, 4, SEEK_SET);

        avio_wl32(pb, file_size);

        avio_seek(pb, swf->duration_pos, SEEK_SET);

        avio_wl16(pb, swf->video_frame_number);

        avio_seek(pb, swf->vframes_pos, SEEK_SET);

        avio_wl16(pb, swf->video_frame_number);

        avio_seek(pb, file_size, SEEK_SET);

    }

    return 0;

}

#if CONFIG_SWF_MUXER

AVOutputFormat ff_swf_muxer = {

    "swf",

    NULL_IF_CONFIG_SMALL("Flash format"),

    "application/x-shockwave-flash",

    "swf",

    sizeof(SWFContext),

    CODEC_ID_MP3,

    CODEC_ID_FLV1,

    swf_write_header,

    swf_write_packet,

    swf_write_trailer,

};

#endif

#if CONFIG_AVM2_MUXER

AVOutputFormat ff_avm2_muxer = {

    "avm2",

    NULL_IF_CONFIG_SMALL("Flash 9 (AVM2) format"),

    "application/x-shockwave-flash",

    NULL,

    sizeof(SWFContext),

    CODEC_ID_MP3,

    CODEC_ID_FLV1,

    swf_write_header,

    swf_write_packet,

    swf_write_trailer,

};

#endif