From b56ff0b261c4432e52e6b66bbd515f5694292b8a Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <cehoyos@ag.or.at>
Date: Sat, 10 Nov 2012 02:25:17 +0100
Subject: [PATCH] Allow forcing a frame size in bytes for image2pipe.

This allows decoding of concatenated frames encoded in
uncompressed formats like v210.
The frame size cannot be generally calculated, FFmpeg
also supports broken encoders.

Fixes ticket #1869.
---
 libavformat/img2dec.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/libavformat/img2dec.c b/libavformat/img2dec.c
index c493f1add7..735541eadc 100644
--- a/libavformat/img2dec.c
+++ b/libavformat/img2dec.c
@@ -61,6 +61,7 @@ typedef struct {
 #endif
     int start_number;
     int start_number_range;
+    int frame_size;
 } VideoDemuxData;
 
 static const int sizes[][2] = {
@@ -372,7 +373,11 @@ static int read_packet(AVFormatContext *s1, AVPacket *pkt)
         f[0] = s1->pb;
         if (url_feof(f[0]))
             return AVERROR(EIO);
-        size[0]= 4096;
+        if (s->frame_size > 0) {
+            size[0] = s->frame_size;
+        } else {
+            size[0]= 4096;
+        }
     }
 
     if (av_new_packet(pkt, size[0] + size[1] + size[2]) < 0)
@@ -427,6 +432,7 @@ static const AVOption options[] = {
     { "start_number", "set first number in the sequence",    OFFSET(start_number), AV_OPT_TYPE_INT,    {.i64 = 0},    0, INT_MAX, DEC },
     { "start_number_range", "set range for looking at the first sequence number", OFFSET(start_number_range), AV_OPT_TYPE_INT, {.i64 = 5}, 1, INT_MAX, DEC },
     { "video_size",   "set video size",                      OFFSET(video_size),   AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
+    { "frame_size",   "force frame size in bytes",           OFFSET(frame_size),   AV_OPT_TYPE_INT,    {.i64 = 0},    0, INT_MAX, DEC },
     { NULL },
 };