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ffmpeg / libavcodec / mxpegdec.c @ ce02f9be

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/*
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 * MxPEG decoder
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 * Copyright (c) 2011 Anatoly Nenashev
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * MxPEG decoder
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 */
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#include "mjpeg.h"
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#include "mjpegdec.h"
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typedef struct MXpegDecodeContext {
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    MJpegDecodeContext jpg;
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    AVFrame picture[2]; /* pictures array */
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    int picture_index; /* index of current picture */
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    int got_sof_data; /* true if SOF data successfully parsed */
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    int got_mxm_bitmask; /* true if MXM bitmask available */
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    uint8_t *mxm_bitmask; /* bitmask buffer */
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    unsigned bitmask_size; /* size of bitmask */
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    int has_complete_frame; /* true if has complete frame */
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    uint8_t *completion_bitmask; /* completion bitmask of macroblocks */
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    unsigned mb_width, mb_height; /* size of picture in MB's from MXM header */
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} MXpegDecodeContext;
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static av_cold int mxpeg_decode_init(AVCodecContext *avctx)
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{
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    MXpegDecodeContext *s = avctx->priv_data;
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    s->picture[0].reference = s->picture[1].reference = 3;
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    s->jpg.picture_ptr      = &s->picture[0];
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    ff_mjpeg_decode_init(avctx);
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    return 0;
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}
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static int mxpeg_decode_app(MXpegDecodeContext *s,
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                            const uint8_t *buf_ptr, int buf_size)
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{
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    int len;
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    if (buf_size < 2)
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        return 0;
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    len = AV_RB16(buf_ptr);
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    skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
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    return 0;
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}
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static int mxpeg_decode_mxm(MXpegDecodeContext *s,
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                            const uint8_t *buf_ptr, int buf_size)
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{
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    unsigned bitmask_size, mb_count;
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    int i;
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    s->mb_width  = AV_RL16(buf_ptr+4);
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    s->mb_height = AV_RL16(buf_ptr+6);
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    mb_count = s->mb_width * s->mb_height;
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    bitmask_size = (mb_count + 7) >> 3;
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    if (bitmask_size > buf_size - 12) {
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        av_log(s->jpg.avctx, AV_LOG_ERROR,
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               "MXM bitmask is not complete\n");
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        return AVERROR(EINVAL);
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    }
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    if (s->bitmask_size != bitmask_size) {
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        av_freep(&s->mxm_bitmask);
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        s->mxm_bitmask = av_malloc(bitmask_size);
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        if (!s->mxm_bitmask) {
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            av_log(s->jpg.avctx, AV_LOG_ERROR,
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                   "MXM bitmask memory allocation error\n");
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            return AVERROR(ENOMEM);
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        }
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        av_freep(&s->completion_bitmask);
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        s->completion_bitmask = av_mallocz(bitmask_size);
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        if (!s->completion_bitmask) {
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            av_log(s->jpg.avctx, AV_LOG_ERROR,
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                   "Completion bitmask memory allocation error\n");
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            return AVERROR(ENOMEM);
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        }
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        s->bitmask_size = bitmask_size;
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    }
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    memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size);
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    s->got_mxm_bitmask = 1;
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    if (!s->has_complete_frame) {
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        uint8_t completion_check = 0xFF;
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        for (i = 0; i < bitmask_size; ++i) {
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            s->completion_bitmask[i] |= s->mxm_bitmask[i];
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            completion_check &= s->completion_bitmask[i];
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        }
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        s->has_complete_frame = !(completion_check ^ 0xFF);
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    }
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    return 0;
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}
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static int mxpeg_decode_com(MXpegDecodeContext *s,
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                            const uint8_t *buf_ptr, int buf_size)
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{
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    int len, ret = 0;
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    if (buf_size < 2)
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        return 0;
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    len = AV_RB16(buf_ptr);
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    if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) {
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        ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2);
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    }
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    skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));
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    return ret;
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}
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static int mxpeg_check_dimensions(MXpegDecodeContext *s, MJpegDecodeContext *jpg,
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                                  AVFrame *reference_ptr)
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{
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    if ((jpg->width + 0x0F)>>4 != s->mb_width ||
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        (jpg->height + 0x0F)>>4 != s->mb_height) {
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        av_log(jpg->avctx, AV_LOG_ERROR,
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               "Picture dimensions stored in SOF and MXM mismatch\n");
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        return AVERROR(EINVAL);
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    }
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    if (reference_ptr->data[0]) {
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        int i;
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        for (i = 0; i < MAX_COMPONENTS; ++i) {
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            if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) ||
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                 reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) {
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                av_log(jpg->avctx, AV_LOG_ERROR,
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                       "Dimensions of current and reference picture mismatch\n");
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                return AVERROR(EINVAL);
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            }
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        }
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    }
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    return 0;
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}
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static int mxpeg_decode_frame(AVCodecContext *avctx,
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                          void *data, int *data_size,
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                          AVPacket *avpkt)
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{
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    const uint8_t *buf = avpkt->data;
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    int buf_size = avpkt->size;
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    MXpegDecodeContext *s = avctx->priv_data;
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    MJpegDecodeContext *jpg = &s->jpg;
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    const uint8_t *buf_end, *buf_ptr;
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    const uint8_t *unescaped_buf_ptr;
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    int unescaped_buf_size;
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    int start_code;
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    AVFrame *picture = data;
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    int ret;
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    buf_ptr = buf;
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    buf_end = buf + buf_size;
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    jpg->got_picture = 0;
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    s->got_mxm_bitmask = 0;
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    while (buf_ptr < buf_end) {
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        start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
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                                          &unescaped_buf_ptr, &unescaped_buf_size);
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        if (start_code < 0)
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            goto the_end;
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        {
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            init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8);
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            if (start_code >= APP0 && start_code <= APP15) {
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                mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size);
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            }
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            switch (start_code) {
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            case SOI:
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                if (jpg->got_picture) //emulating EOI
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                    goto the_end;
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                break;
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            case EOI:
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                goto the_end;
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            case DQT:
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                ret = ff_mjpeg_decode_dqt(jpg);
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                if (ret < 0) {
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                    av_log(avctx, AV_LOG_ERROR,
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                           "quantization table decode error\n");
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                    return ret;
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                }
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                break;
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            case DHT:
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                ret = ff_mjpeg_decode_dht(jpg);
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                if (ret < 0) {
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                    av_log(avctx, AV_LOG_ERROR,
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                           "huffman table decode error\n");
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                    return ret;
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                }
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                break;
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            case COM:
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                ret = mxpeg_decode_com(s, unescaped_buf_ptr,
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                                       unescaped_buf_size);
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                if (ret < 0)
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                    return ret;
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                break;
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            case SOF0:
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                s->got_sof_data = 0;
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                ret = ff_mjpeg_decode_sof(jpg);
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                if (ret < 0) {
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                    av_log(avctx, AV_LOG_ERROR,
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                           "SOF data decode error\n");
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                    return ret;
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                }
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                if (jpg->interlaced) {
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                    av_log(avctx, AV_LOG_ERROR,
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                           "Interlaced mode not supported in MxPEG\n");
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                    return AVERROR(EINVAL);
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                }
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                s->got_sof_data = 1;
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                break;
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            case SOS:
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                if (!s->got_sof_data) {
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                    av_log(avctx, AV_LOG_WARNING,
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                           "Can not process SOS without SOF data, skipping\n");
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                    break;
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                }
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                if (!jpg->got_picture) {
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                    if (jpg->first_picture) {
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                        av_log(avctx, AV_LOG_WARNING,
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                               "First picture has no SOF, skipping\n");
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                        break;
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                    }
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                    if (!s->got_mxm_bitmask){
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                        av_log(avctx, AV_LOG_WARNING,
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                               "Non-key frame has no MXM, skipping\n");
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                        break;
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                    }
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                    /* use stored SOF data to allocate current picture */
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                    if (jpg->picture_ptr->data[0])
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                        avctx->release_buffer(avctx, jpg->picture_ptr);
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                    if (avctx->get_buffer(avctx, jpg->picture_ptr) < 0) {
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                        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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                        return AVERROR(ENOMEM);
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                    }
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                    jpg->picture_ptr->pict_type = FF_P_TYPE;
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                    jpg->picture_ptr->key_frame = 0;
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                    jpg->got_picture = 1;
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                } else {
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                    jpg->picture_ptr->pict_type = FF_I_TYPE;
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                    jpg->picture_ptr->key_frame = 1;
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                }
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                if (s->got_mxm_bitmask) {
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                    AVFrame *reference_ptr = &s->picture[s->picture_index ^ 1];
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                    if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0)
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                        break;
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                    /* allocate dummy reference picture if needed */
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                    if (!reference_ptr->data[0] &&
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                        avctx->get_buffer(avctx, reference_ptr) < 0) {
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                        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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                        return AVERROR(ENOMEM);
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                    }
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                    ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, reference_ptr);
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                } else {
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                    ff_mjpeg_decode_sos(jpg, NULL, NULL);
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                }
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                break;
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            }
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            buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3;
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        }
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    }
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the_end:
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    if (jpg->got_picture) {
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        *data_size = sizeof(AVFrame);
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        *picture = *jpg->picture_ptr;
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        s->picture_index ^= 1;
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        jpg->picture_ptr = &s->picture[s->picture_index];
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        if (!s->has_complete_frame) {
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            if (!s->got_mxm_bitmask)
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                s->has_complete_frame = 1;
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            else
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                *data_size = 0;
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        }
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    }
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    return buf_ptr - buf;
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}
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static av_cold int mxpeg_decode_end(AVCodecContext *avctx)
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{
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    MXpegDecodeContext *s = avctx->priv_data;
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    MJpegDecodeContext *jpg = &s->jpg;
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    int i;
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    jpg->picture_ptr = NULL;
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    ff_mjpeg_decode_end(avctx);
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    for (i = 0; i < 2; ++i) {
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        if (s->picture[i].data[0])
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            avctx->release_buffer(avctx, &s->picture[i]);
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    }
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    av_freep(&s->mxm_bitmask);
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    av_freep(&s->completion_bitmask);
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    return 0;
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}
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AVCodec ff_mxpeg_decoder = {
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    .name           = "mxpeg",
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    .long_name      = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"),
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    .type           = AVMEDIA_TYPE_VIDEO,
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    .id             = CODEC_ID_MXPEG,
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    .priv_data_size = sizeof(MXpegDecodeContext),
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    .init           = mxpeg_decode_init,
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    .close          = mxpeg_decode_end,
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    .decode         = mxpeg_decode_frame,
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    .capabilities   = CODEC_CAP_DR1,
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    .max_lowres     = 3
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};