diff options
Diffstat (limited to 'libavcodec/mxpegdec.c')
-rw-r--r-- | libavcodec/mxpegdec.c | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/libavcodec/mxpegdec.c b/libavcodec/mxpegdec.c new file mode 100644 index 0000000..7d6f759 --- /dev/null +++ b/libavcodec/mxpegdec.c @@ -0,0 +1,340 @@ +/* + * MxPEG decoder + * Copyright (c) 2011 Anatoly Nenashev + * + * 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 + */ + + +/** + * @file + * MxPEG decoder + */ + +#include "mjpeg.h" +#include "mjpegdec.h" + +typedef struct MXpegDecodeContext { + MJpegDecodeContext jpg; + AVFrame picture[2]; /* pictures array */ + int picture_index; /* index of current picture */ + int got_sof_data; /* true if SOF data successfully parsed */ + int got_mxm_bitmask; /* true if MXM bitmask available */ + uint8_t *mxm_bitmask; /* bitmask buffer */ + unsigned bitmask_size; /* size of bitmask */ + int has_complete_frame; /* true if has complete frame */ + uint8_t *completion_bitmask; /* completion bitmask of macroblocks */ + unsigned mb_width, mb_height; /* size of picture in MB's from MXM header */ +} MXpegDecodeContext; + +static av_cold int mxpeg_decode_init(AVCodecContext *avctx) +{ + MXpegDecodeContext *s = avctx->priv_data; + + s->picture[0].reference = s->picture[1].reference = 3; + s->jpg.picture_ptr = &s->picture[0]; + ff_mjpeg_decode_init(avctx); + + return 0; +} + +static int mxpeg_decode_app(MXpegDecodeContext *s, + const uint8_t *buf_ptr, int buf_size) +{ + int len; + if (buf_size < 2) + return 0; + len = AV_RB16(buf_ptr); + skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size)); + + return 0; +} + +static int mxpeg_decode_mxm(MXpegDecodeContext *s, + const uint8_t *buf_ptr, int buf_size) +{ + unsigned bitmask_size, mb_count; + int i; + + s->mb_width = AV_RL16(buf_ptr+4); + s->mb_height = AV_RL16(buf_ptr+6); + mb_count = s->mb_width * s->mb_height; + + bitmask_size = (mb_count + 7) >> 3; + if (bitmask_size > buf_size - 12) { + av_log(s->jpg.avctx, AV_LOG_ERROR, + "MXM bitmask is not complete\n"); + return AVERROR(EINVAL); + } + + if (s->bitmask_size != bitmask_size) { + av_freep(&s->mxm_bitmask); + s->mxm_bitmask = av_malloc(bitmask_size); + if (!s->mxm_bitmask) { + av_log(s->jpg.avctx, AV_LOG_ERROR, + "MXM bitmask memory allocation error\n"); + return AVERROR(ENOMEM); + } + + av_freep(&s->completion_bitmask); + s->completion_bitmask = av_mallocz(bitmask_size); + if (!s->completion_bitmask) { + av_log(s->jpg.avctx, AV_LOG_ERROR, + "Completion bitmask memory allocation error\n"); + return AVERROR(ENOMEM); + } + + s->bitmask_size = bitmask_size; + } + + memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size); + s->got_mxm_bitmask = 1; + + if (!s->has_complete_frame) { + uint8_t completion_check = 0xFF; + for (i = 0; i < bitmask_size; ++i) { + s->completion_bitmask[i] |= s->mxm_bitmask[i]; + completion_check &= s->completion_bitmask[i]; + } + s->has_complete_frame = !(completion_check ^ 0xFF); + } + + return 0; +} + +static int mxpeg_decode_com(MXpegDecodeContext *s, + const uint8_t *buf_ptr, int buf_size) +{ + int len, ret = 0; + if (buf_size < 2) + return 0; + len = AV_RB16(buf_ptr); + if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) { + ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2); + } + skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size)); + + return ret; +} + +static int mxpeg_check_dimensions(MXpegDecodeContext *s, MJpegDecodeContext *jpg, + AVFrame *reference_ptr) +{ + if ((jpg->width + 0x0F)>>4 != s->mb_width || + (jpg->height + 0x0F)>>4 != s->mb_height) { + av_log(jpg->avctx, AV_LOG_ERROR, + "Picture dimensions stored in SOF and MXM mismatch\n"); + return AVERROR(EINVAL); + } + + if (reference_ptr->data[0]) { + int i; + for (i = 0; i < MAX_COMPONENTS; ++i) { + if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) || + reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) { + av_log(jpg->avctx, AV_LOG_ERROR, + "Dimensions of current and reference picture mismatch\n"); + return AVERROR(EINVAL); + } + } + } + + return 0; +} + +static int mxpeg_decode_frame(AVCodecContext *avctx, + void *data, int *data_size, + AVPacket *avpkt) +{ + const uint8_t *buf = avpkt->data; + int buf_size = avpkt->size; + MXpegDecodeContext *s = avctx->priv_data; + MJpegDecodeContext *jpg = &s->jpg; + const uint8_t *buf_end, *buf_ptr; + const uint8_t *unescaped_buf_ptr; + int unescaped_buf_size; + int start_code; + AVFrame *picture = data; + int ret; + + buf_ptr = buf; + buf_end = buf + buf_size; + jpg->got_picture = 0; + s->got_mxm_bitmask = 0; + while (buf_ptr < buf_end) { + start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end, + &unescaped_buf_ptr, &unescaped_buf_size); + if (start_code < 0) + goto the_end; + { + init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8); + + if (start_code >= APP0 && start_code <= APP15) { + mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size); + } + + switch (start_code) { + case SOI: + if (jpg->got_picture) //emulating EOI + goto the_end; + break; + case EOI: + goto the_end; + case DQT: + ret = ff_mjpeg_decode_dqt(jpg); + if (ret < 0) { + av_log(avctx, AV_LOG_ERROR, + "quantization table decode error\n"); + return ret; + } + break; + case DHT: + ret = ff_mjpeg_decode_dht(jpg); + if (ret < 0) { + av_log(avctx, AV_LOG_ERROR, + "huffman table decode error\n"); + return ret; + } + break; + case COM: + ret = mxpeg_decode_com(s, unescaped_buf_ptr, + unescaped_buf_size); + if (ret < 0) + return ret; + break; + case SOF0: + s->got_sof_data = 0; + ret = ff_mjpeg_decode_sof(jpg); + if (ret < 0) { + av_log(avctx, AV_LOG_ERROR, + "SOF data decode error\n"); + return ret; + } + if (jpg->interlaced) { + av_log(avctx, AV_LOG_ERROR, + "Interlaced mode not supported in MxPEG\n"); + return AVERROR(EINVAL); + } + s->got_sof_data = 1; + break; + case SOS: + if (!s->got_sof_data) { + av_log(avctx, AV_LOG_WARNING, + "Can not process SOS without SOF data, skipping\n"); + break; + } + if (!jpg->got_picture) { + if (jpg->first_picture) { + av_log(avctx, AV_LOG_WARNING, + "First picture has no SOF, skipping\n"); + break; + } + if (!s->got_mxm_bitmask){ + av_log(avctx, AV_LOG_WARNING, + "Non-key frame has no MXM, skipping\n"); + break; + } + /* use stored SOF data to allocate current picture */ + if (jpg->picture_ptr->data[0]) + avctx->release_buffer(avctx, jpg->picture_ptr); + if (avctx->get_buffer(avctx, jpg->picture_ptr) < 0) { + av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); + return AVERROR(ENOMEM); + } + jpg->picture_ptr->pict_type = FF_P_TYPE; + jpg->picture_ptr->key_frame = 0; + jpg->got_picture = 1; + } else { + jpg->picture_ptr->pict_type = FF_I_TYPE; + jpg->picture_ptr->key_frame = 1; + } + + if (s->got_mxm_bitmask) { + AVFrame *reference_ptr = &s->picture[s->picture_index ^ 1]; + if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0) + break; + + /* allocate dummy reference picture if needed */ + if (!reference_ptr->data[0] && + avctx->get_buffer(avctx, reference_ptr) < 0) { + av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); + return AVERROR(ENOMEM); + } + + ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, reference_ptr); + } else { + ff_mjpeg_decode_sos(jpg, NULL, NULL); + } + + break; + } + + buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3; + } + + } + +the_end: + if (jpg->got_picture) { + *data_size = sizeof(AVFrame); + *picture = *jpg->picture_ptr; + s->picture_index ^= 1; + jpg->picture_ptr = &s->picture[s->picture_index]; + + if (!s->has_complete_frame) { + if (!s->got_mxm_bitmask) + s->has_complete_frame = 1; + else + *data_size = 0; + } + } + + return buf_ptr - buf; +} + +static av_cold int mxpeg_decode_end(AVCodecContext *avctx) +{ + MXpegDecodeContext *s = avctx->priv_data; + MJpegDecodeContext *jpg = &s->jpg; + int i; + + jpg->picture_ptr = NULL; + ff_mjpeg_decode_end(avctx); + + for (i = 0; i < 2; ++i) { + if (s->picture[i].data[0]) + avctx->release_buffer(avctx, &s->picture[i]); + } + + av_freep(&s->mxm_bitmask); + av_freep(&s->completion_bitmask); + + return 0; +} + +AVCodec ff_mxpeg_decoder = { + .name = "mxpeg", + .long_name = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"), + .type = AVMEDIA_TYPE_VIDEO, + .id = CODEC_ID_MXPEG, + .priv_data_size = sizeof(MXpegDecodeContext), + .init = mxpeg_decode_init, + .close = mxpeg_decode_end, + .decode = mxpeg_decode_frame, + .capabilities = CODEC_CAP_DR1, + .max_lowres = 3 +}; |