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
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/mem.h"
28 typedef struct H264BSFContext {
34 static int alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size,
35 const uint8_t *sps_pps, uint32_t sps_pps_size,
36 const uint8_t *in, uint32_t in_size)
38 uint32_t offset = *poutbuf_size;
39 uint8_t nal_header_size = offset ? 3 : 4;
42 *poutbuf_size += sps_pps_size + in_size + nal_header_size;
43 if ((err = av_reallocp(poutbuf,
44 *poutbuf_size + AV_INPUT_BUFFER_PADDING_SIZE)) < 0) {
49 memcpy(*poutbuf + offset, sps_pps, sps_pps_size);
50 memcpy(*poutbuf + sps_pps_size + nal_header_size + offset, in, in_size);
52 AV_WB32(*poutbuf + sps_pps_size, 1);
54 (*poutbuf + offset + sps_pps_size)[0] =
55 (*poutbuf + offset + sps_pps_size)[1] = 0;
56 (*poutbuf + offset + sps_pps_size)[2] = 1;
62 static int h264_extradata_to_annexb(AVCodecContext *avctx, const int padding)
65 uint64_t total_size = 0;
66 uint8_t *out = NULL, unit_nb, sps_done = 0,
67 sps_seen = 0, pps_seen = 0;
68 const uint8_t *extradata = avctx->extradata + 4;
69 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
70 int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
73 return AVERROR(EINVAL);
75 /* retrieve sps and pps unit(s) */
76 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
78 unit_nb = *extradata++; /* number of pps unit(s) */
90 unit_size = AV_RB16(extradata);
91 total_size += unit_size + 4;
92 if (total_size > INT_MAX - padding ||
93 extradata + 2 + unit_size > avctx->extradata +
94 avctx->extradata_size) {
96 return AVERROR(EINVAL);
98 if ((err = av_reallocp(&out, total_size + padding)) < 0)
100 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
101 memcpy(out + total_size - unit_size, extradata + 2, unit_size);
102 extradata += 2 + unit_size;
104 if (!unit_nb && !sps_done++) {
105 unit_nb = *extradata++; /* number of pps unit(s) */
112 memset(out + total_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
115 av_log(avctx, AV_LOG_WARNING,
116 "Warning: SPS NALU missing or invalid. "
117 "The resulting stream may not play.\n");
120 av_log(avctx, AV_LOG_WARNING,
121 "Warning: PPS NALU missing or invalid. "
122 "The resulting stream may not play.\n");
124 av_free(avctx->extradata);
125 avctx->extradata = out;
126 avctx->extradata_size = total_size;
131 static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
132 AVCodecContext *avctx, const char *args,
133 uint8_t **poutbuf, int *poutbuf_size,
134 const uint8_t *buf, int buf_size,
137 H264BSFContext *ctx = bsfc->priv_data;
140 uint32_t cumul_size = 0;
141 const uint8_t *buf_end = buf + buf_size;
144 /* nothing to filter */
145 if (!avctx->extradata || avctx->extradata_size < 6) {
146 *poutbuf = (uint8_t *)buf;
147 *poutbuf_size = buf_size;
151 /* retrieve sps and pps NAL units from extradata */
152 if (!ctx->extradata_parsed) {
153 ret = h264_extradata_to_annexb(avctx, AV_INPUT_BUFFER_PADDING_SIZE);
156 ctx->length_size = ret;
158 ctx->extradata_parsed = 1;
164 if (buf + ctx->length_size > buf_end)
167 if (ctx->length_size == 1) {
169 } else if (ctx->length_size == 2) {
170 nal_size = AV_RB16(buf);
172 nal_size = AV_RB32(buf);
174 buf += ctx->length_size;
175 unit_type = *buf & 0x1f;
177 if (buf + nal_size > buf_end || nal_size < 0)
180 /* prepend only to the first type 5 NAL unit of an IDR picture */
181 if (ctx->first_idr && unit_type == 5) {
182 if (alloc_and_copy(poutbuf, poutbuf_size,
183 avctx->extradata, avctx->extradata_size,
188 if (alloc_and_copy(poutbuf, poutbuf_size,
189 NULL, 0, buf, nal_size) < 0)
191 if (!ctx->first_idr && unit_type == 1)
196 cumul_size += nal_size + ctx->length_size;
197 } while (cumul_size < buf_size);
204 return AVERROR(EINVAL);
207 AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
209 sizeof(H264BSFContext),
210 h264_mp4toannexb_filter,