[FFmpeg-cvslog] libavcodec/j2kenc: Allow Encoder to use SOP and EPH markers

[Gautam Ramakrishnan]

ffmpeg | branch: master | Gautam Ramakrishnan <gautamramk at gmail.com> | Tue Aug  4 18:46:02 2020 +0530| [5508e7bf8a2aa49fc75813e00f021843637fdf04] | committer: Michael Niedermayer

libavcodec/j2kenc: Allow Encoder to use SOP and EPH markers

This patch allows the encoder to use SOP and EPH
markers. This would be useful as these markers
provide better error detection mechanisms.

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5508e7bf8a2aa49fc75813e00f021843637fdf04
---

 libavcodec/j2kenc.c | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/libavcodec/j2kenc.c b/libavcodec/j2kenc.c
index 5ebc1f3a99..fad013521b 100644
--- a/libavcodec/j2kenc.c
+++ b/libavcodec/j2kenc.c
@@ -129,6 +129,8 @@ typedef struct {
 
     int format;
     int pred;
+    int sop;
+    int eph;
 } Jpeg2000EncoderContext;
 
 
@@ -308,13 +310,18 @@ static int put_siz(Jpeg2000EncoderContext *s)
 static int put_cod(Jpeg2000EncoderContext *s)
 {
     Jpeg2000CodingStyle *codsty = &s->codsty;
+    uint8_t scod = 0;
 
     if (s->buf_end - s->buf < 14)
         return -1;
 
     bytestream_put_be16(&s->buf, JPEG2000_COD);
     bytestream_put_be16(&s->buf, 12); // Lcod
-    bytestream_put_byte(&s->buf, 0);  // Scod
+    if (s->sop)
+        scod |= JPEG2000_CSTY_SOP;
+    if (s->eph)
+        scod |= JPEG2000_CSTY_EPH;
+    bytestream_put_byte(&s->buf, scod);  // Scod
     // SGcod
     bytestream_put_byte(&s->buf, 0); // progression level
     bytestream_put_be16(&s->buf, 1); // num of layers
@@ -719,14 +726,18 @@ static void putnumpasses(Jpeg2000EncoderContext *s, int n)
 
 
 static int encode_packet(Jpeg2000EncoderContext *s, Jpeg2000ResLevel *rlevel, int precno,
-                          uint8_t *expn, int numgbits)
+                          uint8_t *expn, int numgbits, int packetno)
 {
     int bandno, empty = 1;
-
     // init bitstream
     *s->buf = 0;
     s->bit_index = 0;
 
+    if (s->sop) {
+        bytestream_put_be16(&s->buf, JPEG2000_SOP);
+        bytestream_put_be16(&s->buf, 4);
+        bytestream_put_be16(&s->buf, packetno);
+    }
     // header
 
     // is the packet empty?
@@ -794,6 +805,10 @@ static int encode_packet(Jpeg2000EncoderContext *s, Jpeg2000ResLevel *rlevel, in
         }
     }
     j2k_flush(s);
+    if (s->eph) {
+        bytestream_put_be16(&s->buf, JPEG2000_EPH);
+    }
+
     for (bandno = 0; bandno < rlevel->nbands; bandno++){
         Jpeg2000Band *band = rlevel->band + bandno;
         Jpeg2000Prec *prec = band->prec + precno;
@@ -821,7 +836,7 @@ static int encode_packets(Jpeg2000EncoderContext *s, Jpeg2000Tile *tile, int til
     int compno, reslevelno, ret;
     Jpeg2000CodingStyle *codsty = &s->codsty;
     Jpeg2000QuantStyle  *qntsty = &s->qntsty;
-
+    int packetno = 0;
     av_log(s->avctx, AV_LOG_DEBUG, "tier2\n");
     // lay-rlevel-comp-pos progression
     for (reslevelno = 0; reslevelno < codsty->nreslevels; reslevelno++){
@@ -830,7 +845,7 @@ static int encode_packets(Jpeg2000EncoderContext *s, Jpeg2000Tile *tile, int til
             Jpeg2000ResLevel *reslevel = s->tile[tileno].comp[compno].reslevel + reslevelno;
             for (precno = 0; precno < reslevel->num_precincts_x * reslevel->num_precincts_y; precno++){
                 if ((ret = encode_packet(s, reslevel, precno, qntsty->expn + (reslevelno ? 3*reslevelno-2 : 0),
-                              qntsty->nguardbits)) < 0)
+                              qntsty->nguardbits, packetno++)) < 0)
                     return ret;
             }
         }
@@ -1244,7 +1259,8 @@ static const AVOption options[] = {
     { "pred",          "DWT Type",          OFFSET(pred),          AV_OPT_TYPE_INT,   { .i64 = 0           }, 0,         1,           VE, "pred"        },
     { "dwt97int",      NULL,                0,                     AV_OPT_TYPE_CONST, { .i64 = 0           }, INT_MIN, INT_MAX,       VE, "pred"        },
     { "dwt53",         NULL,                0,                     AV_OPT_TYPE_CONST, { .i64 = 0           }, INT_MIN, INT_MAX,       VE, "pred"        },
-
+    { "sop",           "SOP marker",        OFFSET(sop),           AV_OPT_TYPE_INT,   { .i64 = 0           }, 0,         1,           VE, },
+    { "eph",           "EPH marker",        OFFSET(eph),           AV_OPT_TYPE_INT,   { .i64 = 0           }, 0,         1,           VE, },
     { NULL }
 };