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 {
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 tmp = av_realloc(*poutbuf, *poutbuf_size + FF_INPUT_BUFFER_PADDING_SIZE);
45 return AVERROR(ENOMEM);
48 memcpy(*poutbuf + offset, sps_pps, sps_pps_size);
49 memcpy(*poutbuf + sps_pps_size + nal_header_size + offset, in, in_size);
51 AV_WB32(*poutbuf + sps_pps_size, 1);
53 (*poutbuf + offset + sps_pps_size)[0] =
54 (*poutbuf + offset + sps_pps_size)[1] = 0;
55 (*poutbuf + offset + sps_pps_size)[2] = 1;
61 static int h264_extradata_to_annexb(AVCodecContext *avctx, const int padding)
64 uint64_t total_size = 0;
65 uint8_t *out = NULL, unit_nb, sps_done = 0,
66 sps_seen = 0, pps_seen = 0;
67 const uint8_t *extradata = avctx->extradata + 4;
68 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
69 int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
71 /* retrieve sps and pps unit(s) */
72 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
82 unit_size = AV_RB16(extradata);
83 total_size += unit_size + 4;
84 if (total_size > INT_MAX - padding ||
85 extradata + 2 + unit_size > avctx->extradata +
86 avctx->extradata_size) {
88 return AVERROR(EINVAL);
90 tmp = av_realloc(out, total_size + padding);
93 return AVERROR(ENOMEM);
96 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
97 memcpy(out + total_size - unit_size, extradata + 2, unit_size);
98 extradata += 2 + unit_size;
100 if (!unit_nb && !sps_done++) {
101 unit_nb = *extradata++; /* number of pps unit(s) */
108 memset(out + total_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
111 av_log(avctx, AV_LOG_WARNING,
112 "Warning: SPS NALU missing or invalid. "
113 "The resulting stream may not play.\n");
116 av_log(avctx, AV_LOG_WARNING,
117 "Warning: PPS NALU missing or invalid. "
118 "The resulting stream may not play.\n");
120 av_free(avctx->extradata);
121 avctx->extradata = out;
122 avctx->extradata_size = total_size;
127 static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
128 AVCodecContext *avctx, const char *args,
129 uint8_t **poutbuf, int *poutbuf_size,
130 const uint8_t *buf, int buf_size,
133 H264BSFContext *ctx = bsfc->priv_data;
137 uint32_t cumul_size = 0;
138 const uint8_t *buf_end = buf + buf_size;
141 /* nothing to filter */
142 if (!avctx->extradata || avctx->extradata_size < 6) {
143 *poutbuf = (uint8_t *)buf;
144 *poutbuf_size = buf_size;
148 /* retrieve sps and pps NAL units from extradata */
149 if (!ctx->extradata_parsed) {
150 ret = h264_extradata_to_annexb(avctx, FF_INPUT_BUFFER_PADDING_SIZE);
153 ctx->length_size = ret;
155 ctx->extradata_parsed = 1;
161 ret= AVERROR(EINVAL);
162 if (buf + ctx->length_size > buf_end)
165 for (nal_size = 0, i = 0; i<ctx->length_size; i++)
166 nal_size = (nal_size << 8) | buf[i];
168 buf += ctx->length_size;
169 unit_type = *buf & 0x1f;
171 if (buf + nal_size > buf_end || nal_size < 0)
174 /* prepend only to the first type 5 NAL unit of an IDR picture */
175 if (ctx->first_idr && unit_type == 5) {
176 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
177 avctx->extradata, avctx->extradata_size,
182 if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
183 NULL, 0, buf, nal_size)) < 0)
185 if (!ctx->first_idr && unit_type == 1)
190 cumul_size += nal_size + ctx->length_size;
191 } while (cumul_size < buf_size);
201 AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
203 sizeof(H264BSFContext),
204 h264_mp4toannexb_filter,