move mjpeg-b decoder in its own file

Originally committed as revision 9073 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 149 insertions, 0 deletions

diff --git a/libavcodec/mjpegbdec.c b/libavcodec/mjpegbdec.c
new file mode 100644
index 0000000000..0f71dd60af
--- /dev/null
+++ b/libavcodec/mjpegbdec.c
@@ -0,0 +1,149 @@
+/*
+ * Apple MJPEG-B decoder
+ * Copyright (c) 2002 Alex Beregszaszi
+ *
+ * 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 mjpegbdec.c
+ * Apple MJPEG-B decoder.
+ */
+
+#include "avcodec.h"
+#include "mjpeg.h"
+#include "mjpegdec.h"
+
+
+static int mjpegb_decode_frame(AVCodecContext *avctx,
+                              void *data, int *data_size,
+                              uint8_t *buf, int buf_size)
+{
+    MJpegDecodeContext *s = avctx->priv_data;
+    uint8_t *buf_end, *buf_ptr;
+    AVFrame *picture = data;
+    GetBitContext hgb; /* for the header */
+    uint32_t dqt_offs, dht_offs, sof_offs, sos_offs, second_field_offs;
+    uint32_t field_size, sod_offs;
+
+    buf_ptr = buf;
+    buf_end = buf + buf_size;
+
+read_header:
+    /* reset on every SOI */
+    s->restart_interval = 0;
+    s->restart_count = 0;
+    s->mjpb_skiptosod = 0;
+
+    init_get_bits(&hgb, buf_ptr, /*buf_size*/(buf_end - buf_ptr)*8);
+
+    skip_bits(&hgb, 32); /* reserved zeros */
+
+    if (get_bits_long(&hgb, 32) != MKBETAG('m','j','p','g'))
+    {
+        av_log(avctx, AV_LOG_WARNING, "not mjpeg-b (bad fourcc)\n");
+        return 0;
+    }
+
+    field_size = get_bits_long(&hgb, 32); /* field size */
+    av_log(avctx, AV_LOG_DEBUG, "field size: 0x%x\n", field_size);
+    skip_bits(&hgb, 32); /* padded field size */
+    second_field_offs = get_bits_long(&hgb, 32);
+    av_log(avctx, AV_LOG_DEBUG, "second field offs: 0x%x\n", second_field_offs);
+
+    dqt_offs = get_bits_long(&hgb, 32);
+    av_log(avctx, AV_LOG_DEBUG, "dqt offs: 0x%x\n", dqt_offs);
+    if (dqt_offs)
+    {
+        init_get_bits(&s->gb, buf+dqt_offs, (buf_end - (buf+dqt_offs))*8);
+        s->start_code = DQT;
+        ff_mjpeg_decode_dqt(s);
+    }
+
+    dht_offs = get_bits_long(&hgb, 32);
+    av_log(avctx, AV_LOG_DEBUG, "dht offs: 0x%x\n", dht_offs);
+    if (dht_offs)
+    {
+        init_get_bits(&s->gb, buf+dht_offs, (buf_end - (buf+dht_offs))*8);
+        s->start_code = DHT;
+        ff_mjpeg_decode_dht(s);
+    }
+
+    sof_offs = get_bits_long(&hgb, 32);
+    av_log(avctx, AV_LOG_DEBUG, "sof offs: 0x%x\n", sof_offs);
+    if (sof_offs)
+    {
+        init_get_bits(&s->gb, buf+sof_offs, (buf_end - (buf+sof_offs))*8);
+        s->start_code = SOF0;
+        if (ff_mjpeg_decode_sof(s) < 0)
+            return -1;
+    }
+
+    sos_offs = get_bits_long(&hgb, 32);
+    av_log(avctx, AV_LOG_DEBUG, "sos offs: 0x%x\n", sos_offs);
+    sod_offs = get_bits_long(&hgb, 32);
+    av_log(avctx, AV_LOG_DEBUG, "sod offs: 0x%x\n", sod_offs);
+    if (sos_offs)
+    {
+//        init_get_bits(&s->gb, buf+sos_offs, (buf_end - (buf+sos_offs))*8);
+        init_get_bits(&s->gb, buf+sos_offs, field_size*8);
+        s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16));
+        s->start_code = SOS;
+        ff_mjpeg_decode_sos(s);
+    }
+
+    if (s->interlaced) {
+        s->bottom_field ^= 1;
+        /* if not bottom field, do not output image yet */
+        if (s->bottom_field && second_field_offs)
+        {
+            buf_ptr = buf + second_field_offs;
+            second_field_offs = 0;
+            goto read_header;
+            }
+    }
+
+    //XXX FIXME factorize, this looks very similar to the EOI code
+
+    *picture= s->picture;
+    *data_size = sizeof(AVFrame);
+
+    if(!s->lossless){
+        picture->quality= FFMAX(FFMAX(s->qscale[0], s->qscale[1]), s->qscale[2]);
+        picture->qstride= 0;
+        picture->qscale_table= s->qscale_table;
+        memset(picture->qscale_table, picture->quality, (s->width+15)/16);
+        if(avctx->debug & FF_DEBUG_QP)
+            av_log(avctx, AV_LOG_DEBUG, "QP: %d\n", picture->quality);
+        picture->quality*= FF_QP2LAMBDA;
+    }
+
+    return buf_ptr - buf;
+}
+
+AVCodec mjpegb_decoder = {
+    "mjpegb",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_MJPEGB,
+    sizeof(MJpegDecodeContext),
+    ff_mjpeg_decode_init,
+    NULL,
+    ff_mjpeg_decode_end,
+    mjpegb_decode_frame,
+    CODEC_CAP_DR1,
+    NULL
+};