2 * H.264 MP4 to Annex B byte stream format filter
3 * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/intreadwrite.h"
25 typedef struct H264BSFContext
{
31 static int alloc_and_copy(uint8_t **poutbuf
, int *poutbuf_size
,
32 const uint8_t *sps_pps
, uint32_t sps_pps_size
,
33 const uint8_t *in
, uint32_t in_size
) {
34 uint32_t offset
= *poutbuf_size
;
35 uint8_t nal_header_size
= offset
? 3 : 4;
38 *poutbuf_size
+= sps_pps_size
+in_size
+nal_header_size
;
39 tmp
= av_realloc(*poutbuf
, *poutbuf_size
);
41 return AVERROR(ENOMEM
);
44 memcpy(*poutbuf
+offset
, sps_pps
, sps_pps_size
);
45 memcpy(*poutbuf
+sps_pps_size
+nal_header_size
+offset
, in
, in_size
);
47 AV_WB32(*poutbuf
+sps_pps_size
, 1);
49 (*poutbuf
+offset
+sps_pps_size
)[0] = (*poutbuf
+offset
+sps_pps_size
)[1] = 0;
50 (*poutbuf
+offset
+sps_pps_size
)[2] = 1;
56 static int h264_mp4toannexb_filter(AVBitStreamFilterContext
*bsfc
,
57 AVCodecContext
*avctx
, const char *args
,
58 uint8_t **poutbuf
, int *poutbuf_size
,
59 const uint8_t *buf
, int buf_size
,
61 H264BSFContext
*ctx
= bsfc
->priv_data
;
64 uint32_t cumul_size
= 0;
65 const uint8_t *buf_end
= buf
+ buf_size
;
67 /* nothing to filter */
68 if (!avctx
->extradata
|| avctx
->extradata_size
< 6) {
69 *poutbuf
= (uint8_t*) buf
;
70 *poutbuf_size
= buf_size
;
74 /* retrieve sps and pps NAL units from extradata */
75 if (!ctx
->extradata_parsed
) {
77 uint64_t total_size
= 0;
78 uint8_t *out
= NULL
, unit_nb
, sps_done
= 0, sps_seen
= 0, pps_seen
= 0;
79 const uint8_t *extradata
= avctx
->extradata
+4;
80 static const uint8_t nalu_header
[4] = {0, 0, 0, 1};
82 /* retrieve length coded size */
83 ctx
->length_size
= (*extradata
++ & 0x3) + 1;
84 if (ctx
->length_size
== 3)
85 return AVERROR(EINVAL
);
87 /* retrieve sps and pps unit(s) */
88 unit_nb
= *extradata
++ & 0x1f; /* number of sps unit(s) */
90 unit_nb
= *extradata
++; /* number of pps unit(s) */
102 unit_size
= AV_RB16(extradata
);
103 total_size
+= unit_size
+4;
104 if (total_size
> INT_MAX
- FF_INPUT_BUFFER_PADDING_SIZE
||
105 extradata
+2+unit_size
> avctx
->extradata
+avctx
->extradata_size
) {
107 return AVERROR(EINVAL
);
109 tmp
= av_realloc(out
, total_size
+ FF_INPUT_BUFFER_PADDING_SIZE
);
112 return AVERROR(ENOMEM
);
115 memcpy(out
+total_size
-unit_size
-4, nalu_header
, 4);
116 memcpy(out
+total_size
-unit_size
, extradata
+2, unit_size
);
117 extradata
+= 2+unit_size
;
119 if (!unit_nb
&& !sps_done
++) {
120 unit_nb
= *extradata
++; /* number of pps unit(s) */
127 memset(out
+ total_size
, 0, FF_INPUT_BUFFER_PADDING_SIZE
);
130 av_log(avctx
, AV_LOG_WARNING
, "Warning: SPS NALU missing or invalid. The resulting stream may not play.\n");
132 av_log(avctx
, AV_LOG_WARNING
, "Warning: PPS NALU missing or invalid. The resulting stream may not play.\n");
134 av_free(avctx
->extradata
);
135 avctx
->extradata
= out
;
136 avctx
->extradata_size
= total_size
;
138 ctx
->extradata_parsed
= 1;
144 if (buf
+ ctx
->length_size
> buf_end
)
147 if (ctx
->length_size
== 1) {
149 } else if (ctx
->length_size
== 2) {
150 nal_size
= AV_RB16(buf
);
152 nal_size
= AV_RB32(buf
);
154 buf
+= ctx
->length_size
;
155 unit_type
= *buf
& 0x1f;
157 if (buf
+ nal_size
> buf_end
|| nal_size
< 0)
160 /* prepend only to the first type 5 NAL unit of an IDR picture */
161 if (ctx
->first_idr
&& unit_type
== 5) {
162 if (alloc_and_copy(poutbuf
, poutbuf_size
,
163 avctx
->extradata
, avctx
->extradata_size
,
168 if (alloc_and_copy(poutbuf
, poutbuf_size
,
172 if (!ctx
->first_idr
&& unit_type
== 1)
177 cumul_size
+= nal_size
+ ctx
->length_size
;
178 } while (cumul_size
< buf_size
);
185 return AVERROR(EINVAL
);
188 AVBitStreamFilter ff_h264_mp4toannexb_bsf
= {
190 sizeof(H264BSFContext
),
191 h264_mp4toannexb_filter
,