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 FFmpeg.
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 {
31 uint8_t idr_sps_pps_seen;
35 static int alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size,
36 const uint8_t *sps_pps, uint32_t sps_pps_size,
37 const uint8_t *in, uint32_t in_size)
39 uint32_t offset = *poutbuf_size;
40 uint8_t nal_header_size = offset ? 3 : 4;
43 *poutbuf_size += sps_pps_size + in_size + nal_header_size;
44 if ((err = av_reallocp(poutbuf,
45 *poutbuf_size + FF_INPUT_BUFFER_PADDING_SIZE)) < 0) {
50 memcpy(*poutbuf + offset, sps_pps, sps_pps_size);
51 memcpy(*poutbuf + sps_pps_size + nal_header_size + offset, in, in_size);
53 AV_WB32(*poutbuf + sps_pps_size, 1);
55 (*poutbuf + offset + sps_pps_size)[0] =
56 (*poutbuf + offset + sps_pps_size)[1] = 0;
57 (*poutbuf + offset + sps_pps_size)[2] = 1;
63 static int h264_extradata_to_annexb(AVCodecContext *avctx, const int padding)
66 uint64_t total_size = 0;
67 uint8_t *out = NULL, unit_nb, sps_done = 0,
68 sps_seen = 0, pps_seen = 0;
69 const uint8_t *extradata = avctx->extradata + 4;
70 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
71 int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
73 /* retrieve sps and pps unit(s) */
74 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
84 unit_size = AV_RB16(extradata);
85 total_size += unit_size + 4;
86 if (total_size > INT_MAX - padding) {
87 av_log(avctx, AV_LOG_ERROR,
88 "Too big extradata size, corrupted stream or invalid MP4/AVCC bitstream\n");
90 return AVERROR(EINVAL);
92 if (extradata + 2 + unit_size > avctx->extradata + avctx->extradata_size) {
93 av_log(avctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, "
94 "corrupted stream or invalid MP4/AVCC bitstream\n");
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, FF_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;
141 uint32_t cumul_size = 0;
142 const uint8_t *buf_end = buf + buf_size;
145 /* nothing to filter */
146 if (!avctx->extradata || avctx->extradata_size < 6) {
147 *poutbuf = (uint8_t *)buf;
148 *poutbuf_size = buf_size;
152 /* retrieve sps and pps NAL units from extradata */
153 if (!ctx->extradata_parsed) {
154 ret = h264_extradata_to_annexb(avctx, FF_INPUT_BUFFER_PADDING_SIZE);
157 ctx->length_size = ret;
159 ctx->idr_sps_pps_seen = 0;
160 ctx->extradata_parsed = 1;
166 ret= AVERROR(EINVAL);
167 if (buf + ctx->length_size > buf_end)
170 for (nal_size = 0, i = 0; i<ctx->length_size; i++)
171 nal_size = (nal_size << 8) | buf[i];
173 buf += ctx->length_size;
174 unit_type = *buf & 0x1f;
176 if (buf + nal_size > buf_end || nal_size < 0)
179 if (unit_type == 7 || unit_type == 8)
180 ctx->idr_sps_pps_seen = 1;
182 /* if this is a new IDR picture following an IDR picture, reset the idr flag.
183 * Just check first_mb_in_slice to be 0 as this is the simplest solution.
184 * This could be checking idr_pic_id instead, but would complexify the parsing. */
185 if (!ctx->new_idr && unit_type == 5 && (buf[1] & 0x80))
188 /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
189 if (ctx->new_idr && unit_type == 5 && !ctx->idr_sps_pps_seen) {
190 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
191 avctx->extradata, avctx->extradata_size,
196 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
197 NULL, 0, buf, nal_size)) < 0)
199 if (!ctx->new_idr && unit_type == 1) {
201 ctx->idr_sps_pps_seen = 0;
206 cumul_size += nal_size + ctx->length_size;
207 } while (cumul_size < buf_size);
217 AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
218 .name = "h264_mp4toannexb",
219 .priv_data_size = sizeof(H264BSFContext),
220 .filter = h264_mp4toannexb_filter,