lossless mjpeg encoding (planar yuv & RGB) and somerelated bugfixes

Originally committed as revision 1968 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/allcodecs.c

@@ -63,6 +63,7 @@ void avcodec_register_all(void)
     register_avcodec(&wmv2_encoder);
 #endif
     register_avcodec(&mjpeg_encoder);
+    register_avcodec(&ljpeg_encoder);
     register_avcodec(&huffyuv_encoder);
     register_avcodec(&asv1_encoder);
     register_avcodec(&ffv1_encoder);

libavcodec/avcodec.h

@@ -31,6 +31,7 @@ enum CodecID {
     CODEC_ID_AC3,
     CODEC_ID_MJPEG,
     CODEC_ID_MJPEGB,
+    CODEC_ID_LJPEG,
     CODEC_ID_MPEG4,
     CODEC_ID_RAWVIDEO,
     CODEC_ID_MSMPEG4V1,
@@ -98,7 +99,7 @@ enum PixelFormat {
     PIX_FMT_BGR24,     ///< Packed pixel, 3 bytes per pixel, BGRBGR...
     PIX_FMT_YUV422P,   ///< Planar YUV 4:2:2 (1 Cr & Cb sample per 2x1 Y samples)
     PIX_FMT_YUV444P,   ///< Planar YUV 4:4:4 (1 Cr & Cb sample per 1x1 Y samples)
-    PIX_FMT_RGBA32,    ///< always stored in cpu endianness 
+    PIX_FMT_RGBA32,    ///< Packed pixel, 4 bytes per pixel, BGRABGRA...
     PIX_FMT_YUV410P,   ///< Planar YUV 4:1:0 (1 Cr & Cb sample per 4x4 Y samples)
     PIX_FMT_YUV411P,   ///< Planar YUV 4:1:1 (1 Cr & Cb sample per 4x1 Y samples)
     PIX_FMT_RGB565,    ///< always stored in cpu endianness 
@@ -1226,6 +1227,7 @@ extern AVCodec h263_encoder;
 extern AVCodec h263p_encoder;
 extern AVCodec rv10_encoder;
 extern AVCodec mjpeg_encoder;
+extern AVCodec ljpeg_encoder;
 extern AVCodec mpeg4_encoder;
 extern AVCodec msmpeg4v1_encoder;
 extern AVCodec msmpeg4v2_encoder;

libavcodec/mpegvideo.c

@@ -528,8 +528,7 @@ int MPV_encode_init(AVCodecContext *avctx)
 {
     MpegEncContext *s = avctx->priv_data;
     int i;
-
-    avctx->pix_fmt = PIX_FMT_YUV420P;
+    int chroma_h_shift, chroma_v_shift;
 
     s->bit_rate = avctx->bit_rate;
     s->bit_rate_tolerance = avctx->bit_rate_tolerance;
@@ -620,22 +619,25 @@ int MPV_encode_init(AVCodecContext *avctx)
         s->intra_quant_bias= avctx->intra_quant_bias;
     if(avctx->inter_quant_bias != FF_DEFAULT_QUANT_BIAS)
         s->inter_quant_bias= avctx->inter_quant_bias;
-    
+        
+    avcodec_get_chroma_sub_sample(avctx->pix_fmt, &chroma_h_shift, &chroma_v_shift);
+
     switch(avctx->codec->id) {
     case CODEC_ID_MPEG1VIDEO:
         s->out_format = FMT_MPEG1;
         s->low_delay= 0; //s->max_b_frames ? 0 : 1;
         avctx->delay= s->low_delay ? 0 : (s->max_b_frames + 1);
         break;
+    case CODEC_ID_LJPEG:
     case CODEC_ID_MJPEG:
         s->out_format = FMT_MJPEG;
         s->intra_only = 1; /* force intra only for jpeg */
         s->mjpeg_write_tables = 1; /* write all tables */
 	s->mjpeg_data_only_frames = 0; /* write all the needed headers */
-        s->mjpeg_vsample[0] = 2; /* set up default sampling factors */
-        s->mjpeg_vsample[1] = 1; /* the only currently supported values */
+        s->mjpeg_vsample[0] = 1<<chroma_v_shift;
+        s->mjpeg_vsample[1] = 1;
         s->mjpeg_vsample[2] = 1; 
-        s->mjpeg_hsample[0] = 2;
+        s->mjpeg_hsample[0] = 1<<chroma_h_shift;
         s->mjpeg_hsample[1] = 1; 
         s->mjpeg_hsample[2] = 1; 
         if (mjpeg_init(s) < 0)