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added interlaced MJPEG support 

Originally committed as revision 70 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Fabrice Bellard 2001-08-11 19:03:30 +00:00
parent 85c242d800
commit 991ae7b6a4
1 changed files with 36 additions and 2 deletions
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38
libavcodec/mjpeg.c
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@ -443,6 +443,12 @@ typedef struct MJpegDecodeContext {
int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
INT16 quant_matrixes[4][64];
VLC vlcs[2][4];
int org_width, org_height; /* size given at codec init */
int first_picture; /* true if decoding first picture */
int interlaced; /* true if interlaced */
int bottom_field; /* true if bottom field */
int width, height;
int nb_components;
int component_id[MAX_COMPONENTS];
@ -479,6 +485,9 @@ static int mjpeg_decode_init(AVCodecContext *avctx)
account FF 00 case */
s->start_code = -1;
s->buf_ptr = s->buffer;
s->first_picture = 1;
s->org_width = avctx->width;
s->org_height = avctx->height;
build_vlc(&s->vlcs[0][0], bits_dc_luminance, val_dc_luminance, 12);
build_vlc(&s->vlcs[0][1], bits_dc_chrominance, val_dc_chrominance, 12);
@ -611,6 +620,14 @@ static int mjpeg_decode_sof0(MJpegDecodeContext *s,
}
s->width = width;
s->height = height;
/* test interlaced mode */
if (s->first_picture &&
s->org_height != 0 &&
s->height < ((s->org_height * 3) / 4)) {
s->interlaced = 1;
s->bottom_field = 0;
}
for(i=0;i<nb_components;i++) {
int w, h, hh, vv;
hh = s->h_max / s->h_count[i];
@ -619,12 +636,15 @@ static int mjpeg_decode_sof0(MJpegDecodeContext *s,
h = (s->height + 8 * vv - 1) / (8 * vv);
w = w * 8;
h = h * 8;
if (s->interlaced)
w *= 2;
s->linesize[i] = w;
/* memory test is done in mjpeg_decode_sos() */
s->current_picture[i] = av_mallocz(w * h);
}
s->first_picture = 0;
}
return 0;
}
@ -788,6 +808,8 @@ static int mjpeg_decode_sos(MJpegDecodeContext *s,
ptr = s->current_picture[c] +
(s->linesize[c] * (v * mb_y + y) * 8) +
(h * mb_x + x) * 8;
if (s->interlaced && s->bottom_field)
ptr += s->linesize[c] >> 1;
put_pixels_clamped(s->block, ptr, s->linesize[c]);
if (++x == h) {
x = 0;
@ -895,12 +917,24 @@ static int mjpeg_decode_frame(AVCodecContext *avctx,
case SOS:
mjpeg_decode_sos(s, s->buffer, input_size);
if (s->start_code == EOI) {
int l;
if (s->interlaced) {
s->bottom_field ^= 1;
/* if not bottom field, do not output image yet */
if (s->bottom_field)
goto the_end;
}
for(i=0;i<3;i++) {
picture->data[i] = s->current_picture[i];
picture->linesize[i] = s->linesize[i];
l = s->linesize[i];
if (s->interlaced)
l >>= 1;
picture->linesize[i] = l;
}
*data_size = sizeof(AVPicture);
avctx->height = s->height;
if (s->interlaced)
avctx->height *= 2;
avctx->width = s->width;
/* XXX: not complete test ! */
switch((s->h_count[0] << 4) | s->v_count[0]) {