On date Thursday 2016-10-13 21:59:19 +0200, Michael Niedermayer encoded:
> On Thu, Oct 13, 2016 at 07:40:59PM +0200, Stefano Sabatini wrote:
> > This allows to probe if the read line was partially discarded.
> > ---
> >  libavformat/aviobuf.c  | 10 +++++++++-
> >  libavformat/internal.h | 14 ++++++++++++++
> >  2 files changed, 23 insertions(+), 1 deletion(-)
> > 
> > diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
> > index 134d627..28183b4 100644
> > --- a/libavformat/aviobuf.c
> > +++ b/libavformat/aviobuf.c
> > @@ -764,18 +764,26 @@ unsigned int avio_rb32(AVIOContext *s)
> >  
> >  int ff_get_line(AVIOContext *s, char *buf, int maxlen)
> >  {
> > -    int i = 0;
> > +    return ff_get_line2(s, buf, maxlen, NULL);
> > +}
> > +
> > +int ff_get_line2(AVIOContext *s, char *buf, int maxlen, int *readlen)
> > +{
> > +    int i = 0, j = 0;
> >      char c;
> >  
> >      do {
> >          c = avio_r8(s);
> >          if (c && i < maxlen-1)
> >              buf[i++] = c;
> > +        j++;
> >      } while (c != '\n' && c != '\r' && c);
> 

> "\n" and "\0" would i belive both have a j=1 but they would have
> differig i
> is that intended ? (seems to me that this would make truncation
> detection more annoying)
> or am i missing something that avoids this difference?

Improved version in attachment.
-- 
FFmpeg = Fascinating Foolish Mystic Puritan Egregious Gymnast
>From 58c1cad434447d48246e153e3a1a391d72d23c7b Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefa...@gmail.com>
Date: Thu, 13 Oct 2016 16:36:30 +0200
Subject: [PATCH] lavf/aviobuf: add ff_get_line2() variant

This allows to probe if the read line was partially discarded.
---
 libavformat/aviobuf.c  | 18 +++++++++++++++---
 libavformat/internal.h | 14 ++++++++++++++
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 134d627..29bcf1e 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -764,18 +764,30 @@ unsigned int avio_rb32(AVIOContext *s)
 
 int ff_get_line(AVIOContext *s, char *buf, int maxlen)
 {
-    int i = 0;
+    return ff_get_line2(s, buf, maxlen, NULL);
+}
+
+int ff_get_line2(AVIOContext *s, char *buf, int maxlen, int *readlen)
+{
+    int i = 0, j = 0;
     char c;
 
-    do {
+    while (1) {
         c = avio_r8(s);
         if (c && i < maxlen-1)
             buf[i++] = c;
-    } while (c != '\n' && c != '\r' && c);
+        if (c != '\n' && c != '\r' && c) {
+            j++;
+        } else {
+            break;
+        }
+    }
     if (c == '\r' && avio_r8(s) != '\n' && !avio_feof(s))
         avio_skip(s, -1);
 
     buf[i] = 0;
+    if (readlen)
+        *readlen = j;
     return i;
 }
 
diff --git a/libavformat/internal.h b/libavformat/internal.h
index 49244fa..fc49571 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -274,6 +274,20 @@ void ff_put_v(AVIOContext *bc, uint64_t val);
  */
 int ff_get_line(AVIOContext *s, char *buf, int maxlen);
 
+/**
+ * Read a whole line of text from AVIOContext. Stop reading after reaching
+ * either a \\n, a \\0 or EOF. The returned string is always \\0-terminated,
+ * and may be truncated if the buffer is too small.
+ *
+ * @param s the read-only AVIOContext
+ * @param buf buffer to store the read line
+ * @param maxlen size of the buffer
+ * @param readlen length of the read line, not including the final \\0
+ * @return the length of the string written in the buffer, not including the
+ *         final \\0
+ */
+int ff_get_line2(AVIOContext *s, char *buf, int maxlen, int *readlen);
+
 #define SPACE_CHARS " \t\r\n"
 
 /**
-- 
1.9.1

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

Reply via email to