PeerStreamer

/*

 * YUV4MPEG format

 * Copyright (c) 2001, 2002, 2003 Fabrice Bellard

 *

 * This file is part of Libav.

 *

 * Libav 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.

 *

 * Libav 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 Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "avformat.h"

#define Y4M_MAGIC "YUV4MPEG2"

#define Y4M_FRAME_MAGIC "FRAME"

#define Y4M_LINE_MAX 256

struct frame_attributes {

    int interlaced_frame;

    int top_field_first;

};

#if CONFIG_YUV4MPEGPIPE_MUXER

static int yuv4_generate_header(AVFormatContext *s, char* buf)

{

    AVStream *st;

    int width, height;

    int raten, rated, aspectn, aspectd, n;

    char inter;

    const char *colorspace = "";

    st = s->streams[0];

    width = st->codec->width;

    height = st->codec->height;

    av_reduce(&raten, &rated, st->codec->time_base.den, st->codec->time_base.num, (1UL<<31)-1);

    aspectn = st->sample_aspect_ratio.num;

    aspectd = st->sample_aspect_ratio.den;

    if ( aspectn == 0 && aspectd == 1 ) aspectd = 0;  // 0:0 means unknown

    inter = 'p'; /* progressive is the default */

    if (st->codec->coded_frame && st->codec->coded_frame->interlaced_frame) {

        inter = st->codec->coded_frame->top_field_first ? 't' : 'b';

    }

    switch(st->codec->pix_fmt) {

    case PIX_FMT_GRAY8:

        colorspace = " Cmono";

        break;

    case PIX_FMT_YUV411P:

        colorspace = " C411 XYSCSS=411";

        break;

    case PIX_FMT_YUV420P:

        colorspace = (st->codec->chroma_sample_location == AVCHROMA_LOC_TOPLEFT)?" C420paldv XYSCSS=420PALDV":

                     (st->codec->chroma_sample_location == AVCHROMA_LOC_LEFT)   ?" C420mpeg2 XYSCSS=420MPEG2":

                     " C420jpeg XYSCSS=420JPEG";

        break;

    case PIX_FMT_YUV422P:

        colorspace = " C422 XYSCSS=422";

        break;

    case PIX_FMT_YUV444P:

        colorspace = " C444 XYSCSS=444";

        break;

    }

    /* construct stream header, if this is the first frame */

    n = snprintf(buf, Y4M_LINE_MAX, "%s W%d H%d F%d:%d I%c A%d:%d%s\n",

                 Y4M_MAGIC,

                 width,

                 height,

                 raten, rated,

                 inter,

                 aspectn, aspectd,

                 colorspace);

    return n;

}

static int yuv4_write_packet(AVFormatContext *s, AVPacket *pkt)

{

    AVStream *st = s->streams[pkt->stream_index];

    AVIOContext *pb = s->pb;

    AVPicture *picture;

    int* first_pkt = s->priv_data;

    int width, height, h_chroma_shift, v_chroma_shift;

    int i, m;

    char buf2[Y4M_LINE_MAX+1];

    char buf1[20];

    uint8_t *ptr, *ptr1, *ptr2;

    picture = (AVPicture *)pkt->data;

    /* for the first packet we have to output the header as well */

    if (*first_pkt) {

        *first_pkt = 0;

        if (yuv4_generate_header(s, buf2) < 0) {

            av_log(s, AV_LOG_ERROR, "Error. YUV4MPEG stream header write failed.\n");

            return AVERROR(EIO);

        } else {

            avio_write(pb, buf2, strlen(buf2));

        }

    }

    /* construct frame header */

    m = snprintf(buf1, sizeof(buf1), "%s\n", Y4M_FRAME_MAGIC);

    avio_write(pb, buf1, strlen(buf1));

    width = st->codec->width;

    height = st->codec->height;

    ptr = picture->data[0];

    for(i=0;i<height;i++) {

        avio_write(pb, ptr, width);

        ptr += picture->linesize[0];

    }

    if (st->codec->pix_fmt != PIX_FMT_GRAY8){

    // Adjust for smaller Cb and Cr planes

    avcodec_get_chroma_sub_sample(st->codec->pix_fmt, &h_chroma_shift, &v_chroma_shift);

    width >>= h_chroma_shift;

    height >>= v_chroma_shift;

    ptr1 = picture->data[1];

    ptr2 = picture->data[2];

    for(i=0;i<height;i++) {     /* Cb */

        avio_write(pb, ptr1, width);

        ptr1 += picture->linesize[1];

    }

    for(i=0;i<height;i++) {     /* Cr */

        avio_write(pb, ptr2, width);

            ptr2 += picture->linesize[2];

    }

    }

    avio_flush(pb);

    return 0;

}

static int yuv4_write_header(AVFormatContext *s)

{

    int* first_pkt = s->priv_data;

    if (s->nb_streams != 1)

        return AVERROR(EIO);

    if (s->streams[0]->codec->pix_fmt == PIX_FMT_YUV411P) {

        av_log(s, AV_LOG_ERROR, "Warning: generating rarely used 4:1:1 YUV stream, some mjpegtools might not work.\n");

    }

    else if ((s->streams[0]->codec->pix_fmt != PIX_FMT_YUV420P) &&

             (s->streams[0]->codec->pix_fmt != PIX_FMT_YUV422P) &&

             (s->streams[0]->codec->pix_fmt != PIX_FMT_GRAY8) &&

             (s->streams[0]->codec->pix_fmt != PIX_FMT_YUV444P)) {

        av_log(s, AV_LOG_ERROR, "ERROR: yuv4mpeg only handles yuv444p, yuv422p, yuv420p, yuv411p and gray pixel formats. Use -pix_fmt to select one.\n");

        return AVERROR(EIO);

    }

    *first_pkt = 1;

    return 0;

}

AVOutputFormat ff_yuv4mpegpipe_muxer = {

    "yuv4mpegpipe",

    NULL_IF_CONFIG_SMALL("YUV4MPEG pipe format"),

    "",

    "y4m",

    sizeof(int),

    CODEC_ID_NONE,

    CODEC_ID_RAWVIDEO,

    yuv4_write_header,

    yuv4_write_packet,

    .flags = AVFMT_RAWPICTURE,

};

#endif

/* Header size increased to allow room for optional flags */

#define MAX_YUV4_HEADER 80

#define MAX_FRAME_HEADER 80

static int yuv4_read_header(AVFormatContext *s, AVFormatParameters *ap)

{

    char header[MAX_YUV4_HEADER+10];  // Include headroom for the longest option

    char *tokstart,*tokend,*header_end;

    int i;

    AVIOContext *pb = s->pb;

    int width=-1, height=-1, raten=0, rated=0, aspectn=0, aspectd=0;

    enum PixelFormat pix_fmt=PIX_FMT_NONE,alt_pix_fmt=PIX_FMT_NONE;

    enum AVChromaLocation chroma_sample_location = AVCHROMA_LOC_UNSPECIFIED;

    AVStream *st;

    struct frame_attributes *s1 = s->priv_data;

    for (i=0; i<MAX_YUV4_HEADER; i++) {

        header[i] = avio_r8(pb);

        if (header[i] == '\n') {

            header[i+1] = 0x20;  // Add a space after last option. Makes parsing "444" vs "444alpha" easier.

            header[i+2] = 0;

            break;

        }

    }

    if (i == MAX_YUV4_HEADER) return -1;

    if (strncmp(header, Y4M_MAGIC, strlen(Y4M_MAGIC))) return -1;

    s1->interlaced_frame = 0;

    s1->top_field_first = 0;

    header_end = &header[i+1]; // Include space

    for(tokstart = &header[strlen(Y4M_MAGIC) + 1]; tokstart < header_end; tokstart++) {

        if (*tokstart==0x20) continue;

        switch (*tokstart++) {

        case 'W': // Width. Required.

            width = strtol(tokstart, &tokend, 10);

            tokstart=tokend;

            break;

        case 'H': // Height. Required.

            height = strtol(tokstart, &tokend, 10);

            tokstart=tokend;

            break;

        case 'C': // Color space

            if (strncmp("420jpeg",tokstart,7)==0) {

                pix_fmt = PIX_FMT_YUV420P;

                chroma_sample_location = AVCHROMA_LOC_CENTER;

            } else if (strncmp("420mpeg2",tokstart,8)==0) {

                pix_fmt = PIX_FMT_YUV420P;

                chroma_sample_location = AVCHROMA_LOC_LEFT;

            } else if (strncmp("420paldv", tokstart, 8)==0) {

                pix_fmt = PIX_FMT_YUV420P;

                chroma_sample_location = AVCHROMA_LOC_TOPLEFT;

            } else if (strncmp("411", tokstart, 3)==0)

                pix_fmt = PIX_FMT_YUV411P;

            else if (strncmp("422", tokstart, 3)==0)

                pix_fmt = PIX_FMT_YUV422P;

            else if (strncmp("444alpha", tokstart, 8)==0) {

                av_log(s, AV_LOG_ERROR, "Cannot handle 4:4:4:4 YUV4MPEG stream.\n");

                return -1;

            } else if (strncmp("444", tokstart, 3)==0)

                pix_fmt = PIX_FMT_YUV444P;

            else if (strncmp("mono",tokstart, 4)==0) {

                pix_fmt = PIX_FMT_GRAY8;

            } else {

                av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains an unknown pixel format.\n");

                return -1;

            }

            while(tokstart<header_end&&*tokstart!=0x20) tokstart++;

            break;

        case 'I': // Interlace type

            switch (*tokstart++){

            case '?':

                break;

            case 'p':

                s1->interlaced_frame=0;

                break;

            case 't':

                s1->interlaced_frame=1;

                s1->top_field_first=1;

                break;

            case 'b':

                s1->interlaced_frame=1;

                s1->top_field_first=0;

                break;

            case 'm':

                av_log(s, AV_LOG_ERROR, "YUV4MPEG stream contains mixed interlaced and non-interlaced frames.\n");

                return -1;

            default:

                av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");

                return -1;

            }

            break;

        case 'F': // Frame rate

            sscanf(tokstart,"%d:%d",&raten,&rated); // 0:0 if unknown

            while(tokstart<header_end&&*tokstart!=0x20) tokstart++;

            break;

        case 'A': // Pixel aspect

            sscanf(tokstart,"%d:%d",&aspectn,&aspectd); // 0:0 if unknown

            while(tokstart<header_end&&*tokstart!=0x20) tokstart++;

            break;

        case 'X': // Vendor extensions

            if (strncmp("YSCSS=",tokstart,6)==0) {

                // Older nonstandard pixel format representation

                tokstart+=6;

                if (strncmp("420JPEG",tokstart,7)==0)

                    alt_pix_fmt=PIX_FMT_YUV420P;

                else if (strncmp("420MPEG2",tokstart,8)==0)

                    alt_pix_fmt=PIX_FMT_YUV420P;

                else if (strncmp("420PALDV",tokstart,8)==0)

                    alt_pix_fmt=PIX_FMT_YUV420P;

                else if (strncmp("411",tokstart,3)==0)

                    alt_pix_fmt=PIX_FMT_YUV411P;

                else if (strncmp("422",tokstart,3)==0)

                    alt_pix_fmt=PIX_FMT_YUV422P;

                else if (strncmp("444",tokstart,3)==0)

                    alt_pix_fmt=PIX_FMT_YUV444P;

            }

            while(tokstart<header_end&&*tokstart!=0x20) tokstart++;

            break;

        }

    }

    if ((width == -1) || (height == -1)) {

        av_log(s, AV_LOG_ERROR, "YUV4MPEG has invalid header.\n");

        return -1;

    }

    if (pix_fmt == PIX_FMT_NONE) {

        if (alt_pix_fmt == PIX_FMT_NONE)

            pix_fmt = PIX_FMT_YUV420P;

        else

            pix_fmt = alt_pix_fmt;

    }

    if (raten <= 0 || rated <= 0) {

        // Frame rate unknown

        raten = 25;

        rated = 1;

    }

    if (aspectn == 0 && aspectd == 0) {

        // Pixel aspect unknown

        aspectd = 1;

    }

    st = av_new_stream(s, 0);

    if(!st)

        return AVERROR(ENOMEM);

    st->codec->width = width;

    st->codec->height = height;

    av_reduce(&raten, &rated, raten, rated, (1UL<<31)-1);

    av_set_pts_info(st, 64, rated, raten);

    st->codec->pix_fmt = pix_fmt;

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codec->codec_id = CODEC_ID_RAWVIDEO;

    st->sample_aspect_ratio= (AVRational){aspectn, aspectd};

    st->codec->chroma_sample_location = chroma_sample_location;

    return 0;

}

static int yuv4_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    int i;

    char header[MAX_FRAME_HEADER+1];

    int packet_size, width, height;

    AVStream *st = s->streams[0];

    struct frame_attributes *s1 = s->priv_data;

    for (i=0; i<MAX_FRAME_HEADER; i++) {

        header[i] = avio_r8(s->pb);

        if (header[i] == '\n') {

            header[i+1] = 0;

            break;

        }

    }

    if (i == MAX_FRAME_HEADER) return -1;

    if (strncmp(header, Y4M_FRAME_MAGIC, strlen(Y4M_FRAME_MAGIC))) return -1;

    width = st->codec->width;

    height = st->codec->height;

    packet_size = avpicture_get_size(st->codec->pix_fmt, width, height);

    if (packet_size < 0)

        return -1;

    if (av_get_packet(s->pb, pkt, packet_size) != packet_size)

        return AVERROR(EIO);

    if (s->streams[0]->codec->coded_frame) {

        s->streams[0]->codec->coded_frame->interlaced_frame = s1->interlaced_frame;

        s->streams[0]->codec->coded_frame->top_field_first = s1->top_field_first;

    }

    pkt->stream_index = 0;

    return 0;

}

static int yuv4_probe(AVProbeData *pd)

{

    /* check file header */

    if (strncmp(pd->buf, Y4M_MAGIC, sizeof(Y4M_MAGIC)-1)==0)

        return AVPROBE_SCORE_MAX;

    else

        return 0;

}

#if CONFIG_YUV4MPEGPIPE_DEMUXER

AVInputFormat ff_yuv4mpegpipe_demuxer = {

    "yuv4mpegpipe",

    NULL_IF_CONFIG_SMALL("YUV4MPEG pipe format"),

    sizeof(struct frame_attributes),

    yuv4_probe,

    yuv4_read_header,

    yuv4_read_packet,

    .extensions = "y4m"

};

#endif