From e15dec10d5eb1fba001714a512779f459a8b51fc Mon Sep 17 00:00:00 2001
From: Leon van Stuivenberg <leonvs@iae.nl>
Date: Mon, 15 Mar 2004 03:29:32 +0000
Subject: [PATCH] decode latency patch by (Leon van Stuivenberg <l dot
 vanstuivenberg at chello dot nl>)

Originally committed as revision 2896 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavformat/avio.h    |  1 +
 libavformat/aviobuf.c | 16 ++++++++++++++++
 libavformat/raw.c     | 31 +++++++++++++++++++++++++------
 3 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/libavformat/avio.h b/libavformat/avio.h
index df287b82141..f668c0ceb01 100644
--- a/libavformat/avio.h
+++ b/libavformat/avio.h
@@ -119,6 +119,7 @@ char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
 void put_flush_packet(ByteIOContext *s);
 
 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
+int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
 int get_byte(ByteIOContext *s);
 unsigned int get_le32(ByteIOContext *s);
 uint64_t get_le64(ByteIOContext *s);
diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index de140966c6b..75f97a5b408 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -309,6 +309,22 @@ int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
     return size1 - size;
 }
 
+int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
+{
+    int len;
+
+    len = s->buf_end - s->buf_ptr;
+    if (len == 0) {
+        fill_buffer(s);
+        len = s->buf_end - s->buf_ptr;
+    }
+    if (len > size)
+        len = size;
+    memcpy(buf, s->buf_ptr, len);
+    s->buf_ptr += len;
+    return len;
+}
+
 unsigned int get_le16(ByteIOContext *s)
 {
     unsigned int val;
diff --git a/libavformat/raw.c b/libavformat/raw.c
index 2fd3e4873d7..b650fd76aef 100644
--- a/libavformat/raw.c
+++ b/libavformat/raw.c
@@ -102,6 +102,25 @@ static int raw_read_packet(AVFormatContext *s, AVPacket *pkt)
     return ret;
 }
 
+static int raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    int ret, size;
+
+    size = RAW_PACKET_SIZE;
+
+    if (av_new_packet(pkt, size) < 0)
+        return -EIO;
+
+    pkt->stream_index = 0;
+    ret = get_partial_buffer(&s->pb, pkt->data, size);
+    if (ret <= 0) {
+        av_free_packet(pkt);
+        return -EIO;
+    }
+    pkt->size = ret;
+    return ret;
+}
+
 static int raw_read_close(AVFormatContext *s)
 {
     return 0;
@@ -247,7 +266,7 @@ AVInputFormat ac3_iformat = {
     0,
     NULL,
     ac3_read_header,
-    raw_read_packet,
+    raw_read_partial_packet,
     raw_read_close,
     .extensions = "ac3",
 };
@@ -273,7 +292,7 @@ AVInputFormat h263_iformat = {
     0,
     h263_probe,
     video_read_header,
-    raw_read_packet,
+    raw_read_partial_packet,
     raw_read_close,
 //    .extensions = "h263", //FIXME remove after writing mpeg4_probe
     .value = CODEC_ID_H263,
@@ -300,7 +319,7 @@ AVInputFormat m4v_iformat = {
     0,
     NULL /*mpegvideo_probe*/,
     video_read_header,
-    raw_read_packet,
+    raw_read_partial_packet,
     raw_read_close,
     .extensions = "m4v", //FIXME remove after writing mpeg4_probe
     .value = CODEC_ID_MPEG4,
@@ -327,7 +346,7 @@ AVInputFormat h264_iformat = {
     0,
     NULL /*mpegvideo_probe*/,
     video_read_header,
-    raw_read_packet,
+    raw_read_partial_packet,
     raw_read_close,
     .extensions = "h26l,h264", //FIXME remove after writing mpeg4_probe
     .value = CODEC_ID_H264,
@@ -354,7 +373,7 @@ AVInputFormat mpegvideo_iformat = {
     0,
     mpegvideo_probe,
     video_read_header,
-    raw_read_packet,
+    raw_read_partial_packet,
     raw_read_close,
     .value = CODEC_ID_MPEG1VIDEO,
 };
@@ -380,7 +399,7 @@ AVInputFormat mjpeg_iformat = {
     0,
     NULL,
     video_read_header,
-    raw_read_packet,
+    raw_read_partial_packet,
     raw_read_close,
     .extensions = "mjpg,mjpeg",
     .value = CODEC_ID_MJPEG,
-- 
2.39.2