mjpeg 4:2:2 encoding support

Originally committed as revision 6550 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mjpeg.c

@@ -613,7 +613,7 @@ static void encode_block(MpegEncContext *s, DCTELEM *block, int n)
     uint16_t *huff_code_ac;
 
     /* DC coef */
-    component = (n <= 3 ? 0 : n - 4 + 1);
+    component = (n <= 3 ? 0 : (n&1) + 1);
     dc = block[0]; /* overflow is impossible */
     val = dc - s->last_dc[component];
     if (n < 4) {
@@ -666,9 +666,16 @@ void mjpeg_encode_mb(MpegEncContext *s,
                      DCTELEM block[6][64])
 {
     int i;
-    for(i=0;i<6;i++) {
+    for(i=0;i<5;i++) {
         encode_block(s, block[i], i);
     }
+    if (s->chroma_format == CHROMA_420) {
+        encode_block(s, block[5], 5);
+    } else {
+        encode_block(s, block[6], 6);
+        encode_block(s, block[5], 5);
+        encode_block(s, block[7], 7);
+    }
 }
 
 static int encode_picture_lossless(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
@@ -1103,7 +1110,7 @@ static int mjpeg_decode_dht(MJpegDecodeContext *s)
 
 static int mjpeg_decode_sof(MJpegDecodeContext *s)
 {
-    int len, nb_components, i, width, height;
+    int len, nb_components, i, width, height, pix_fmt_id;
 
     /* XXX: verify len field validity */
     len = get_bits(&s->gb, 16);
@@ -1188,8 +1195,13 @@ static int mjpeg_decode_sof(MJpegDecodeContext *s)
         return 0;
 
     /* XXX: not complete test ! */
-    switch((s->h_count[0] << 4) | s->v_count[0]) {
-    case 0x11:
+    pix_fmt_id = (s->h_count[0] << 20) | (s->v_count[0] << 16) |
+                 (s->h_count[1] << 12) | (s->v_count[1] <<  8) |
+                 (s->h_count[2] <<  4) |  s->v_count[2];
+    dprintf("pix fmt id %x\n", pix_fmt_id);
+    switch(pix_fmt_id){
+    case 0x222222:
+    case 0x111111:
         if(s->rgb){
             s->avctx->pix_fmt = PIX_FMT_RGBA32;
         }else if(s->nb_components==3)
@@ -1197,11 +1209,12 @@ static int mjpeg_decode_sof(MJpegDecodeContext *s)
         else
             s->avctx->pix_fmt = PIX_FMT_GRAY8;
         break;
-    case 0x21:
+    case 0x211111:
+    case 0x221212:
         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV422P : PIX_FMT_YUVJ422P;
         break;
     default:
-    case 0x22:
+    case 0x221111:
         s->avctx->pix_fmt = s->cs_itu601 ? PIX_FMT_YUV420P : PIX_FMT_YUVJ420P;
         break;
     }

libavcodec/mpegvideo.c

@@ -940,7 +940,8 @@ int MPV_encode_init(AVCodecContext *avctx)
         break;
     case CODEC_ID_LJPEG:
     case CODEC_ID_MJPEG:
-        if(avctx->pix_fmt != PIX_FMT_YUVJ420P && (avctx->pix_fmt != PIX_FMT_YUV420P || avctx->strict_std_compliance>FF_COMPLIANCE_INOFFICIAL)){
+        if(avctx->pix_fmt != PIX_FMT_YUVJ420P && avctx->pix_fmt != PIX_FMT_YUVJ422P &&
+           ((avctx->pix_fmt != PIX_FMT_YUV420P && avctx->pix_fmt != PIX_FMT_YUV422P) || avctx->strict_std_compliance>FF_COMPLIANCE_INOFFICIAL)){
             av_log(avctx, AV_LOG_ERROR, "colorspace not supported in jpeg\n");
             return -1;
         }
@@ -1182,12 +1183,12 @@ int MPV_encode_init(AVCodecContext *avctx)
         s->intra_only = 1; /* force intra only for jpeg */
         s->mjpeg_write_tables = avctx->codec->id != CODEC_ID_JPEGLS;
         s->mjpeg_data_only_frames = 0; /* write all the needed headers */
-        s->mjpeg_vsample[0] = 1<<chroma_v_shift;
-        s->mjpeg_vsample[1] = 1;
-        s->mjpeg_vsample[2] = 1;
-        s->mjpeg_hsample[0] = 1<<chroma_h_shift;
-        s->mjpeg_hsample[1] = 1;
-        s->mjpeg_hsample[2] = 1;
+        s->mjpeg_vsample[0] = 2;
+        s->mjpeg_vsample[1] = 2>>chroma_v_shift;
+        s->mjpeg_vsample[2] = 2>>chroma_v_shift;
+        s->mjpeg_hsample[0] = 2;
+        s->mjpeg_hsample[1] = 2>>chroma_h_shift;
+        s->mjpeg_hsample[2] = 2>>chroma_h_shift;
         if (mjpeg_init(s) < 0)
             return -1;
         avctx->delay=0;
@@ -6842,7 +6843,7 @@ AVCodec mjpeg_encoder = {
     MPV_encode_init,
     MPV_encode_picture,
     MPV_encode_end,
-    .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUVJ420P, -1},
+    .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, -1},
 };
 
 #endif //CONFIG_ENCODERS