codec/packetizer: expose a read-only version of the input format

All code creating a decoder uses decoder_Init().
Packetizer creation needs to be taken care of as well.

include/vlc_codec.h

@@ -105,8 +105,11 @@ struct decoder_t
     module_t *          p_module;
     void               *p_sys;
 
-    /* Input format ie from demuxer (XXX: a lot of field could be invalid) */
+    /* Input format ie from demuxer (XXX: a lot of fields could be invalid) */
     es_format_t         fmt_in;
+    /* Input format ie from demuxer (XXX: a lot of fields could be invalid),
+       cannot be NULL */
+    const es_format_t   *p_fmt_in;
 
     /* Output format of decoder/packetizer */
     es_format_t         fmt_out;

src/input/decoder_helpers.c

@@ -46,6 +46,7 @@ void decoder_Init( decoder_t *p_dec, const es_format_t *restrict p_fmt )
     p_dec->p_module = NULL;
 
     es_format_Copy( &p_dec->fmt_in, p_fmt );
+    p_dec->p_fmt_in = &p_dec->fmt_in;
     es_format_Init( &p_dec->fmt_out, p_fmt->i_cat, 0 );
 }
 

src/input/demux.c

@@ -398,6 +398,7 @@ decoder_t *demux_PacketizerNew( vlc_object_t *p_demux, es_format_t *p_fmt, const
     p_packetizer->pf_packetize = NULL;
 
     p_packetizer->fmt_in = *p_fmt;
+    p_packetizer->p_fmt_in = &p_packetizer->fmt_in;
     es_format_Init( &p_packetizer->fmt_out, p_fmt->i_cat, 0 );
 
     p_packetizer->p_module = module_need( p_packetizer, "packetizer", NULL, false );

test/modules/packetizer/packetizer.h

@@ -82,6 +82,7 @@ static decoder_t *create_packetizer(libvlc_instance_t *vlc,
     p_pack->fmt_in.video.i_frame_rate = num;
     p_pack->fmt_in.video.i_frame_rate_base = den;
     p_pack->fmt_in.b_packetized = false;
+    p_pack->p_fmt_in = &p_pack->fmt_in;
 
     p_pack->p_module = module_need( p_pack, "packetizer", NULL, false );
     if(!p_pack->p_module)