diff --git a/libavcodec/h263_parser.c b/libavcodec/h263_parser.c
index e05b8a4ac4..7a742caa80 100644
--- a/libavcodec/h263_parser.c
+++ b/libavcodec/h263_parser.c
@@ -25,9 +25,16 @@
  */
 
 #include "parser.h"
+#if FF_API_FLAG_TRUNCATED
+/* Nuke this header when removing FF_API_FLAG_TRUNCATED */
 #include "h263_parser.h"
 
 int ff_h263_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){
+#else
+
+static int h263_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
+{
+#endif
     int vop_found, i;
     uint32_t state;
 
@@ -73,7 +80,11 @@ static int h263_parse(AVCodecParserContext *s,
     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
         next = buf_size;
     } else {
+#if FF_API_FLAG_TRUNCATED
         next= ff_h263_find_frame_end(pc, buf, buf_size);
+#else
+        next = h263_find_frame_end(pc, buf, buf_size);
+#endif
 
         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
             *poutbuf = NULL;
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 1aacd07e41..58e03c05d4 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -168,6 +168,7 @@ av_cold void ff_mpeg12_init_vlcs(void)
     ff_thread_once(&init_static_once, mpeg12_init_vlcs);
 }
 
+#if FF_API_FLAG_TRUNCATED
 /**
  * Find the end of the current frame in the bitstream.
  * @return the position of the first byte of the next frame, or -1
@@ -231,6 +232,7 @@ int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size,
     pc->state = state;
     return END_NOT_FOUND;
 }
+#endif
 
 #define MAX_INDEX (64 - 1)
 
diff --git a/libavcodec/mpeg12.h b/libavcodec/mpeg12.h
index a7b94c132a..fb2b37e7c8 100644
--- a/libavcodec/mpeg12.h
+++ b/libavcodec/mpeg12.h
@@ -70,7 +70,9 @@ int ff_mpeg1_decode_block_intra(GetBitContext *gb,
                                 int16_t *block, int index, int qscale);
 
 void ff_mpeg1_clean_buffers(MpegEncContext *s);
+#if FF_API_FLAG_TRUNCATED
 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s);
+#endif
 
 void ff_mpeg1_encode_picture_header(MpegEncContext *s, int picture_number);
 void ff_mpeg1_encode_mb(MpegEncContext *s, int16_t block[8][64],
diff --git a/libavcodec/mpeg4video_parser.c b/libavcodec/mpeg4video_parser.c
index 1b0e2555da..c68c966259 100644
--- a/libavcodec/mpeg4video_parser.c
+++ b/libavcodec/mpeg4video_parser.c
@@ -26,7 +26,10 @@
 #include "parser.h"
 #include "mpegvideo.h"
 #include "mpeg4video.h"
+#if FF_API_FLAG_TRUNCATED
+/* Nuke this header when removing FF_API_FLAG_TRUNCATED */
 #include "mpeg4video_parser.h"
+#endif
 
 struct Mp4vParseContext {
     ParseContext pc;
@@ -34,7 +37,15 @@ struct Mp4vParseContext {
     int first_picture;
 };
 
+#if FF_API_FLAG_TRUNCATED
 int ff_mpeg4_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
+#else
+/**
+ * Find the end of the current frame in the bitstream.
+ * @return the position of the first byte of the next frame, or -1
+ */
+static int mpeg4_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
+#endif
 {
     int vop_found, i;
     uint32_t state;
@@ -138,7 +149,11 @@ static int mpeg4video_parse(AVCodecParserContext *s,
     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
         next = buf_size;
     } else {
+#if FF_API_FLAG_TRUNCATED
         next = ff_mpeg4_find_frame_end(pc, buf, buf_size);
+#else
+        next = mpeg4_find_frame_end(pc, buf, buf_size);
+#endif
 
         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
             *poutbuf      = NULL;
diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h
index 8dfa904577..e90669b776 100644
--- a/libavcodec/mpegvideo.h
+++ b/libavcodec/mpegvideo.h
@@ -49,7 +49,9 @@
 #include "pixblockdsp.h"
 #include "put_bits.h"
 #include "ratecontrol.h"
+#if FF_API_FLAG_TRUNCATED
 #include "parser.h"
+#endif
 #include "mpegutils.h"
 #include "mpeg12data.h"
 #include "qpeldsp.h"
diff --git a/libavcodec/mpegvideo_parser.c b/libavcodec/mpegvideo_parser.c
index 7864224643..39b9f2e43a 100644
--- a/libavcodec/mpegvideo_parser.c
+++ b/libavcodec/mpegvideo_parser.c
@@ -31,6 +31,72 @@ struct MpvParseContext {
     int width, height;
 };
 
+#if !FF_API_FLAG_TRUNCATED
+/**
+ * Find the end of the current frame in the bitstream.
+ * @return the position of the first byte of the next frame, or -1
+ */
+static int mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf,
+                                int buf_size, AVCodecParserContext *s)
+{
+    int i;
+    uint32_t state = pc->state;
+
+    /* EOF considered as end of frame */
+    if (buf_size == 0)
+        return 0;
+
+/*
+ 0  frame start         -> 1/4
+ 1  first_SEQEXT        -> 0/2
+ 2  first field start   -> 3/0
+ 3  second_SEQEXT       -> 2/0
+ 4  searching end
+*/
+
+    for (i = 0; i < buf_size; i++) {
+        av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
+        if (pc->frame_start_found & 1) {
+            if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
+                pc->frame_start_found--;
+            else if (state == EXT_START_CODE + 2) {
+                if ((buf[i] & 3) == 3)
+                    pc->frame_start_found = 0;
+                else
+                    pc->frame_start_found = (pc->frame_start_found + 1) & 3;
+            }
+            state++;
+        } else {
+            i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
+            if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
+                i++;
+                pc->frame_start_found = 4;
+            }
+            if (state == SEQ_END_CODE) {
+                pc->frame_start_found = 0;
+                pc->state = -1;
+                return i + 1;
+            }
+            if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
+                pc->frame_start_found = 0;
+            if (pc->frame_start_found  < 4 && state == EXT_START_CODE)
+                pc->frame_start_found++;
+            if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
+                if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
+                    pc->frame_start_found = 0;
+                    pc->state             = -1;
+                    return i - 3;
+                }
+            }
+            if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
+                ff_fetch_timestamp(s, i - 3, 1, i > 3);
+            }
+        }
+    }
+    pc->state = state;
+    return END_NOT_FOUND;
+}
+#endif
 
 static void mpegvideo_extract_headers(AVCodecParserContext *s,
                                       AVCodecContext *avctx,
@@ -192,7 +258,11 @@ static int mpegvideo_parse(AVCodecParserContext *s,
     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
         next= buf_size;
     }else{
+#if FF_API_FLAG_TRUNCATED
         next= ff_mpeg1_find_frame_end(pc, buf, buf_size, s);
+#else
+        next = mpeg1_find_frame_end(pc, buf, buf_size, s);
+#endif
 
         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
             *poutbuf = NULL;