mjpegenc: do not pass MpegEncContext to ff_mjpeg_encode_picture_header()

This will allow deMpegEncContextizing the LJPEG encoder.

libavcodec/ljpegenc.c

@@ -70,7 +70,8 @@ static int encode_picture_lossless(AVCodecContext *avctx, AVPacket *pkt,
     p->pict_type= AV_PICTURE_TYPE_I;
     p->key_frame= 1;
 
-    ff_mjpeg_encode_picture_header(s);
+    ff_mjpeg_encode_picture_header(avctx, &s->pb, &s->intra_scantable,
+                                   s->intra_matrix);
 
     s->header_bits= put_bits_count(&s->pb);
 

libavcodec/mjpegenc.c

@@ -32,6 +32,8 @@
 
 #include <assert.h>
 
+#include "libavutil/pixdesc.h"
+
 #include "avcodec.h"
 #include "mpegvideo.h"
 #include "mjpeg.h"
@@ -172,78 +174,99 @@ static void jpeg_put_comments(AVCodecContext *avctx, PutBitContext *p)
     }
 }
 
-void ff_mjpeg_encode_picture_header(MpegEncContext *s)
+void ff_mjpeg_encode_picture_header(AVCodecContext *avctx, PutBitContext *pb,
+                                    ScanTable *intra_scantable,
+                                    uint16_t intra_matrix[64])
 {
-    const int lossless= s->avctx->codec_id != AV_CODEC_ID_MJPEG;
+    int chroma_h_shift, chroma_v_shift;
+    const int lossless = avctx->codec_id != AV_CODEC_ID_MJPEG;
+    int hsample[3], vsample[3];
+
+    av_pix_fmt_get_chroma_sub_sample(avctx->pix_fmt, &chroma_h_shift,
+                                     &chroma_v_shift);
+
+    if (avctx->codec->id == AV_CODEC_ID_LJPEG &&
+        avctx->pix_fmt   == AV_PIX_FMT_BGRA) {
+        vsample[0] = hsample[0] =
+        vsample[1] = hsample[1] =
+        vsample[2] = hsample[2] = 1;
+    } else {
+        vsample[0] = 2;
+        vsample[1] = 2 >> chroma_v_shift;
+        vsample[2] = 2 >> chroma_v_shift;
+        hsample[0] = 2;
+        hsample[1] = 2 >> chroma_h_shift;
+        hsample[2] = 2 >> chroma_h_shift;
+    }
 
-    put_marker(&s->pb, SOI);
+    put_marker(pb, SOI);
 
-    jpeg_put_comments(s->avctx, &s->pb);
+    jpeg_put_comments(avctx, pb);
 
-    jpeg_table_header(&s->pb, &s->intra_scantable, s->intra_matrix);
+    jpeg_table_header(pb, intra_scantable, intra_matrix);
 
-    switch(s->avctx->codec_id){
-    case AV_CODEC_ID_MJPEG:  put_marker(&s->pb, SOF0 ); break;
-    case AV_CODEC_ID_LJPEG:  put_marker(&s->pb, SOF3 ); break;
+    switch (avctx->codec_id) {
+    case AV_CODEC_ID_MJPEG:  put_marker(pb, SOF0 ); break;
+    case AV_CODEC_ID_LJPEG:  put_marker(pb, SOF3 ); break;
     default: assert(0);
     }
 
-    put_bits(&s->pb, 16, 17);
-    if(lossless && s->avctx->pix_fmt == AV_PIX_FMT_BGRA)
-        put_bits(&s->pb, 8, 9); /* 9 bits/component RCT */
+    put_bits(pb, 16, 17);
+    if (lossless && avctx->pix_fmt == AV_PIX_FMT_BGRA)
+        put_bits(pb, 8, 9); /* 9 bits/component RCT */
     else
-        put_bits(&s->pb, 8, 8); /* 8 bits/component */
-    put_bits(&s->pb, 16, s->height);
-    put_bits(&s->pb, 16, s->width);
-    put_bits(&s->pb, 8, 3); /* 3 components */
+        put_bits(pb, 8, 8); /* 8 bits/component */
+    put_bits(pb, 16, avctx->height);
+    put_bits(pb, 16, avctx->width);
+    put_bits(pb, 8, 3); /* 3 components */
 
     /* Y component */
-    put_bits(&s->pb, 8, 1); /* component number */
-    put_bits(&s->pb, 4, s->mjpeg_hsample[0]); /* H factor */
-    put_bits(&s->pb, 4, s->mjpeg_vsample[0]); /* V factor */
-    put_bits(&s->pb, 8, 0); /* select matrix */
+    put_bits(pb, 8, 1); /* component number */
+    put_bits(pb, 4, hsample[0]); /* H factor */
+    put_bits(pb, 4, vsample[0]); /* V factor */
+    put_bits(pb, 8, 0); /* select matrix */
 
     /* Cb component */
-    put_bits(&s->pb, 8, 2); /* component number */
-    put_bits(&s->pb, 4, s->mjpeg_hsample[1]); /* H factor */
-    put_bits(&s->pb, 4, s->mjpeg_vsample[1]); /* V factor */
-    put_bits(&s->pb, 8, 0); /* select matrix */
+    put_bits(pb, 8, 2); /* component number */
+    put_bits(pb, 4, hsample[1]); /* H factor */
+    put_bits(pb, 4, vsample[1]); /* V factor */
+    put_bits(pb, 8, 0); /* select matrix */
 
     /* Cr component */
-    put_bits(&s->pb, 8, 3); /* component number */
-    put_bits(&s->pb, 4, s->mjpeg_hsample[2]); /* H factor */
-    put_bits(&s->pb, 4, s->mjpeg_vsample[2]); /* V factor */
-    put_bits(&s->pb, 8, 0); /* select matrix */
+    put_bits(pb, 8, 3); /* component number */
+    put_bits(pb, 4, hsample[2]); /* H factor */
+    put_bits(pb, 4, vsample[2]); /* V factor */
+    put_bits(pb, 8, 0); /* select matrix */
 
     /* scan header */
-    put_marker(&s->pb, SOS);
-    put_bits(&s->pb, 16, 12); /* length */
-    put_bits(&s->pb, 8, 3); /* 3 components */
+    put_marker(pb, SOS);
+    put_bits(pb, 16, 12); /* length */
+    put_bits(pb, 8, 3); /* 3 components */
 
     /* Y component */
-    put_bits(&s->pb, 8, 1); /* index */
-    put_bits(&s->pb, 4, 0); /* DC huffman table index */
-    put_bits(&s->pb, 4, 0); /* AC huffman table index */
+    put_bits(pb, 8, 1); /* index */
+    put_bits(pb, 4, 0); /* DC huffman table index */
+    put_bits(pb, 4, 0); /* AC huffman table index */
 
     /* Cb component */
-    put_bits(&s->pb, 8, 2); /* index */
-    put_bits(&s->pb, 4, 1); /* DC huffman table index */
-    put_bits(&s->pb, 4, lossless ? 0 : 1); /* AC huffman table index */
+    put_bits(pb, 8, 2); /* index */
+    put_bits(pb, 4, 1); /* DC huffman table index */
+    put_bits(pb, 4, lossless ? 0 : 1); /* AC huffman table index */
 
     /* Cr component */
-    put_bits(&s->pb, 8, 3); /* index */
-    put_bits(&s->pb, 4, 1); /* DC huffman table index */
-    put_bits(&s->pb, 4, lossless ? 0 : 1); /* AC huffman table index */
+    put_bits(pb, 8, 3); /* index */
+    put_bits(pb, 4, 1); /* DC huffman table index */
+    put_bits(pb, 4, lossless ? 0 : 1); /* AC huffman table index */
 
-    put_bits(&s->pb, 8, lossless ? s->avctx->prediction_method+1 : 0); /* Ss (not used) */
+    put_bits(pb, 8, lossless ? avctx->prediction_method + 1 : 0); /* Ss (not used) */
 
-    switch(s->avctx->codec_id){
-    case AV_CODEC_ID_MJPEG:  put_bits(&s->pb, 8, 63); break; /* Se (not used) */
-    case AV_CODEC_ID_LJPEG:  put_bits(&s->pb, 8,  0); break; /* not used */
+    switch (avctx->codec_id) {
+    case AV_CODEC_ID_MJPEG:  put_bits(pb, 8, 63); break; /* Se (not used) */
+    case AV_CODEC_ID_LJPEG:  put_bits(pb, 8,  0); break; /* not used */
     default: assert(0);
     }
 
-    put_bits(&s->pb, 8, 0); /* Ah/Al (not used) */
+    put_bits(pb, 8, 0); /* Ah/Al (not used) */
 }
 
 static void escape_FF(MpegEncContext *s, int start)

libavcodec/mjpegenc.h

@@ -51,7 +51,9 @@ typedef struct MJpegContext {
 
 int  ff_mjpeg_encode_init(MpegEncContext *s);
 void ff_mjpeg_encode_close(MpegEncContext *s);
-void ff_mjpeg_encode_picture_header(MpegEncContext *s);
+void ff_mjpeg_encode_picture_header(AVCodecContext *avctx, PutBitContext *pb,
+                                    ScanTable *intra_scantable,
+                                    uint16_t intra_matrix[64]);
 void ff_mjpeg_encode_picture_trailer(MpegEncContext *s);
 void ff_mjpeg_encode_stuffing(PutBitContext *pbc);
 void ff_mjpeg_encode_dc(MpegEncContext *s, int val,

libavcodec/mpegvideo_enc.c

@@ -3296,7 +3296,8 @@ static int encode_picture(MpegEncContext *s, int picture_number)
     switch(s->out_format) {
     case FMT_MJPEG:
         if (CONFIG_MJPEG_ENCODER)
-            ff_mjpeg_encode_picture_header(s);
+            ff_mjpeg_encode_picture_header(s->avctx, &s->pb, &s->intra_scantable,
+                                           s->intra_matrix);
         break;
     case FMT_H261:
         if (CONFIG_H261_ENCODER)