[PATCH 4/4] Add MxPEG decoder

anatoly anatoly.nenashev
Wed Feb 16 21:28:07 CET 2011


---
 libavcodec/Makefile    |    1 +
 libavcodec/allcodecs.c |    1 +
 libavcodec/mxpegdec.c  |  326 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 328 insertions(+), 0 deletions(-)
 create mode 100644 libavcodec/mxpegdec.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 682b626..ee85a88 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -269,6 +269,7 @@ OBJS-$(CONFIG_MSMPEG4V3_ENCODER)       += msmpeg4.o msmpeg4data.o h263dec.o \
 OBJS-$(CONFIG_MSRLE_DECODER)           += msrle.o msrledec.o
 OBJS-$(CONFIG_MSVIDEO1_DECODER)        += msvideo1.o
 OBJS-$(CONFIG_MSZH_DECODER)            += lcldec.o
+OBJS-$(CONFIG_MXPEG_DECODER)           += mxpegdec.o
 OBJS-$(CONFIG_NELLYMOSER_DECODER)      += nellymoserdec.o nellymoser.o
 OBJS-$(CONFIG_NELLYMOSER_ENCODER)      += nellymoserenc.o nellymoser.o
 OBJS-$(CONFIG_NUV_DECODER)             += nuv.o rtjpeg.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 108a3ab..9d37bd9 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -151,6 +151,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER (MSRLE, msrle);
     REGISTER_DECODER (MSVIDEO1, msvideo1);
     REGISTER_DECODER (MSZH, mszh);
+    REGISTER_DECODER (MXPEG, mxpeg);
     REGISTER_DECODER (NUV, nuv);
     REGISTER_ENCDEC  (PAM, pam);
     REGISTER_ENCDEC  (PBM, pbm);
diff --git a/libavcodec/mxpegdec.c b/libavcodec/mxpegdec.c
new file mode 100644
index 0000000..433ae61
--- /dev/null
+++ b/libavcodec/mxpegdec.c
@@ -0,0 +1,326 @@
+/*
+ * MxPEG decoder
+ * Copyright (c) 2011 Anatoly Nenashev
+ *
+ * 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
+ */
+
+
+/**
+ * @file
+ * MxPEG decoder.
+ */
+
+#include "mjpeg.h"
+#include "mjpegdec.h"
+
+int ff_mxpeg_decode_init(AVCodecContext *avctx);
+int ff_mxpeg_decode_end(AVCodecContext *avctx);
+int ff_mxpeg_decode_frame(AVCodecContext *avctx,
+                          void *data, int *data_size,
+                          AVPacket *avpkt);
+
+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;
+
+av_cold int ff_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;
+}
+
+int ff_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;
+                break;
+            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;
+
+                    if (reference_ptr->data[0])
+                        ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, reference_ptr);
+                    else
+                        ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, NULL);
+                } 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;
+}
+
+av_cold int ff_mxpeg_decode_end(AVCodecContext *avctx)
+{
+    MXpegDecodeContext *s = avctx->priv_data;
+    MJpegDecodeContext *jpg = &s->jpg;
+    int i;
+
+    jpg->picture_ptr = 0;
+    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 = ff_mxpeg_decode_init,
+    .close = ff_mxpeg_decode_end,
+    .decode = ff_mxpeg_decode_frame,
+    .capabilities = CODEC_CAP_DR1,
+    .max_lowres = 3
+};
-- 
1.7.1


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