PeerStreamer

/*

 * NuppelVideo decoder

 * Copyright (c) 2006 Reimar Doeffinger

 *

 * 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 <stdio.h>

#include <stdlib.h>

#include "libavutil/bswap.h"

#include "libavutil/lzo.h"

#include "avcodec.h"

#include "dsputil.h"

#include "rtjpeg.h"

typedef struct {

    AVFrame pic;

    int codec_frameheader;

    int quality;

    int width, height;

    unsigned int decomp_size;

    unsigned char* decomp_buf;

    uint32_t lq[64], cq[64];

    RTJpegContext rtj;

    DSPContext dsp;

} NuvContext;

static const uint8_t fallback_lquant[] = {

    16,  11,  10,  16,  24,  40,  51,  61,

    12,  12,  14,  19,  26,  58,  60,  55,

    14,  13,  16,  24,  40,  57,  69,  56,

    14,  17,  22,  29,  51,  87,  80,  62,

    18,  22,  37,  56,  68, 109, 103,  77,

    24,  35,  55,  64,  81, 104, 113,  92,

    49,  64,  78,  87, 103, 121, 120, 101,

    72,  92,  95,  98, 112, 100, 103,  99

};

static const uint8_t fallback_cquant[] = {

    17, 18, 24, 47, 99, 99, 99, 99,

    18, 21, 26, 66, 99, 99, 99, 99,

    24, 26, 56, 99, 99, 99, 99, 99,

    47, 66, 99, 99, 99, 99, 99, 99,

    99, 99, 99, 99, 99, 99, 99, 99,

    99, 99, 99, 99, 99, 99, 99, 99,

    99, 99, 99, 99, 99, 99, 99, 99,

    99, 99, 99, 99, 99, 99, 99, 99

};

/**

 * \brief copy frame data from buffer to AVFrame, handling stride.

 * \param f destination AVFrame

 * \param src source buffer, does not use any line-stride

 * \param width width of the video frame

 * \param height height of the video frame

 */

static void copy_frame(AVFrame *f, const uint8_t *src,

                       int width, int height) {

    AVPicture pic;

    avpicture_fill(&pic, src, PIX_FMT_YUV420P, width, height);

    av_picture_copy((AVPicture *)f, &pic, PIX_FMT_YUV420P, width, height);

}

/**

 * \brief extract quantization tables from codec data into our context

 */

static int get_quant(AVCodecContext *avctx, NuvContext *c,

                     const uint8_t *buf, int size) {

    int i;

    if (size < 2 * 64 * 4) {

        av_log(avctx, AV_LOG_ERROR, "insufficient rtjpeg quant data\n");

        return -1;

    }

    for (i = 0; i < 64; i++, buf += 4)

        c->lq[i] = AV_RL32(buf);

    for (i = 0; i < 64; i++, buf += 4)

        c->cq[i] = AV_RL32(buf);

    return 0;

}

/**

 * \brief set quantization tables from a quality value

 */

static void get_quant_quality(NuvContext *c, int quality) {

    int i;

    quality = FFMAX(quality, 1);

    for (i = 0; i < 64; i++) {

        c->lq[i] = (fallback_lquant[i] << 7) / quality;

        c->cq[i] = (fallback_cquant[i] << 7) / quality;

    }

}

static int codec_reinit(AVCodecContext *avctx, int width, int height, int quality) {

    NuvContext *c = avctx->priv_data;

    width = (width + 1) & ~1;

    height = (height + 1) & ~1;

    if (quality >= 0)

        get_quant_quality(c, quality);

    if (width != c->width || height != c->height) {

        if (avcodec_check_dimensions(avctx, height, width) < 0)

            return 0;

        avctx->width = c->width = width;

        avctx->height = c->height = height;

        c->decomp_size = c->height * c->width * 3 / 2;

        c->decomp_buf = av_realloc(c->decomp_buf, c->decomp_size + AV_LZO_OUTPUT_PADDING);

        if (!c->decomp_buf) {

            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");

            return 0;

        }

        rtjpeg_decode_init(&c->rtj, &c->dsp, c->width, c->height, c->lq, c->cq);

    } else if (quality != c->quality)

        rtjpeg_decode_init(&c->rtj, &c->dsp, c->width, c->height, c->lq, c->cq);

    return 1;

}

static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,

                        const uint8_t *buf, int buf_size) {

    NuvContext *c = avctx->priv_data;

    AVFrame *picture = data;

    int orig_size = buf_size;

    int keyframe;

    int result;

    enum {NUV_UNCOMPRESSED = '0', NUV_RTJPEG = '1',

          NUV_RTJPEG_IN_LZO = '2', NUV_LZO = '3',

          NUV_BLACK = 'N', NUV_COPY_LAST = 'L'} comptype;

    if (buf_size < 12) {

        av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");

        return -1;

    }

    // codec data (rtjpeg quant tables)

    if (buf[0] == 'D' && buf[1] == 'R') {

        int ret;

        // skip rest of the frameheader.

        buf = &buf[12];

        buf_size -= 12;

        ret = get_quant(avctx, c, buf, buf_size);

        if (ret < 0)

            return ret;

        rtjpeg_decode_init(&c->rtj, &c->dsp, c->width, c->height, c->lq, c->cq);

        return orig_size;

    }

    if (buf[0] != 'V' || buf_size < 12) {

        av_log(avctx, AV_LOG_ERROR, "not a nuv video frame\n");

        return -1;

    }

    comptype = buf[1];

    switch (comptype) {

        case NUV_RTJPEG_IN_LZO:

        case NUV_RTJPEG:

            keyframe = !buf[2]; break;

        case NUV_COPY_LAST:

            keyframe = 0; break;

        default:

            keyframe = 1; break;

    }

    // skip rest of the frameheader.

    buf = &buf[12];

    buf_size -= 12;

    if (comptype == NUV_RTJPEG_IN_LZO || comptype == NUV_LZO) {

        int outlen = c->decomp_size, inlen = buf_size;

        if (av_lzo1x_decode(c->decomp_buf, &outlen, buf, &inlen))

            av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");

        buf = c->decomp_buf;

        buf_size = c->decomp_size;

    }

    if (c->codec_frameheader) {

        int w, h, q;

        if (buf_size < 12) {

            av_log(avctx, AV_LOG_ERROR, "invalid nuv video frame\n");

            return -1;

        }

        w = AV_RL16(&buf[6]);

        h = AV_RL16(&buf[8]);

        q = buf[10];

        if (!codec_reinit(avctx, w, h, q))

            return -1;

        buf = &buf[12];

        buf_size -= 12;

    }

    if (keyframe && c->pic.data[0])

        avctx->release_buffer(avctx, &c->pic);

    c->pic.reference = 1;

    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE |

                          FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;

    result = keyframe ? avctx->get_buffer(avctx, &c->pic) : avctx->reget_buffer(avctx, &c->pic);

    if (result < 0) {

        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

        return -1;

    }

    c->pic.pict_type = keyframe ? FF_I_TYPE : FF_P_TYPE;

    c->pic.key_frame = keyframe;

    // decompress/copy/whatever data

    switch (comptype) {

        case NUV_LZO:

        case NUV_UNCOMPRESSED: {

            int height = c->height;

            if (buf_size < c->width * height * 3 / 2) {

                av_log(avctx, AV_LOG_ERROR, "uncompressed frame too short\n");

                height = buf_size / c->width / 3 * 2;

            }

            copy_frame(&c->pic, buf, c->width, height);

            break;

        }

        case NUV_RTJPEG_IN_LZO:

        case NUV_RTJPEG: {

            rtjpeg_decode_frame_yuv420(&c->rtj, &c->pic, buf, buf_size);

            break;

        }

        case NUV_BLACK: {

            memset(c->pic.data[0], 0, c->width * c->height);

            memset(c->pic.data[1], 128, c->width * c->height / 4);

            memset(c->pic.data[2], 128, c->width * c->height / 4);

            break;

        }

        case NUV_COPY_LAST: {

            /* nothing more to do here */

            break;

        }

        default:

            av_log(avctx, AV_LOG_ERROR, "unknown compression\n");

            return -1;

    }

    *picture = c->pic;

    *data_size = sizeof(AVFrame);

    return orig_size;

}

static av_cold int decode_init(AVCodecContext *avctx) {

    NuvContext *c = avctx->priv_data;

    avctx->pix_fmt = PIX_FMT_YUV420P;

    c->pic.data[0] = NULL;

    c->decomp_buf = NULL;

    c->quality = -1;

    c->width = 0;

    c->height = 0;

    c->codec_frameheader = avctx->codec_tag == MKTAG('R', 'J', 'P', 'G');

    if (avctx->extradata_size)

        get_quant(avctx, c, avctx->extradata, avctx->extradata_size);

    dsputil_init(&c->dsp, avctx);

    if (!codec_reinit(avctx, avctx->width, avctx->height, -1))

        return 1;

    return 0;

}

static av_cold int decode_end(AVCodecContext *avctx) {

    NuvContext *c = avctx->priv_data;

    av_freep(&c->decomp_buf);

    if (c->pic.data[0])

        avctx->release_buffer(avctx, &c->pic);

    return 0;

}

AVCodec nuv_decoder = {

    "nuv",

    CODEC_TYPE_VIDEO,

    CODEC_ID_NUV,

    sizeof(NuvContext),

    decode_init,

    NULL,

    decode_end,

    decode_frame,

    CODEC_CAP_DR1,

    .long_name = NULL_IF_CONFIG_SMALL("NuppelVideo"),

};