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 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
72 return AVERROR(EINVAL);
74 /* retrieve sps and pps unit(s) */
75 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
77 unit_nb = *extradata++; /* number of pps unit(s) */
89 unit_size = AV_RB16(extradata);
90 total_size += unit_size + 4;
91 if (total_size > INT_MAX - padding ||
92 extradata + 2 + unit_size > avctx->extradata +
93 avctx->extradata_size) {
95 return AVERROR(EINVAL);
97 tmp = av_realloc(out, total_size + padding);
100 return AVERROR(ENOMEM);
103 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
104 memcpy(out + total_size - unit_size, extradata + 2, unit_size);
105 extradata += 2 + unit_size;
107 if (!unit_nb && !sps_done++) {
108 unit_nb = *extradata++; /* number of pps unit(s) */
115 memset(out + total_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
118 av_log(avctx, AV_LOG_WARNING,
119 "Warning: SPS NALU missing or invalid. "
120 "The resulting stream may not play.\n");
123 av_log(avctx, AV_LOG_WARNING,
124 "Warning: PPS NALU missing or invalid. "
125 "The resulting stream may not play.\n");
127 av_free(avctx->extradata);
128 avctx->extradata = out;
129 avctx->extradata_size = total_size;
134 static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
135 AVCodecContext *avctx, const char *args,
136 uint8_t **poutbuf, int *poutbuf_size,
137 const uint8_t *buf, int buf_size,
140 H264BSFContext *ctx = bsfc->priv_data;
143 uint32_t cumul_size = 0;
144 const uint8_t *buf_end = buf + buf_size;
147 /* nothing to filter */
148 if (!avctx->extradata || avctx->extradata_size < 6) {
149 *poutbuf = (uint8_t *)buf;
150 *poutbuf_size = buf_size;
154 /* retrieve sps and pps NAL units from extradata */
155 if (!ctx->extradata_parsed) {
156 ret = h264_extradata_to_annexb(avctx, FF_INPUT_BUFFER_PADDING_SIZE);
159 ctx->length_size = ret;
161 ctx->extradata_parsed = 1;
167 if (buf + ctx->length_size > buf_end)
170 if (ctx->length_size == 1) {
172 } else if (ctx->length_size == 2) {
173 nal_size = AV_RB16(buf);
175 nal_size = AV_RB32(buf);
177 buf += ctx->length_size;
178 unit_type = *buf & 0x1f;
180 if (buf + nal_size > buf_end || nal_size < 0)
183 /* prepend only to the first type 5 NAL unit of an IDR picture */
184 if (ctx->first_idr && unit_type == 5) {
185 if (alloc_and_copy(poutbuf, poutbuf_size,
186 avctx->extradata, avctx->extradata_size,
191 if (alloc_and_copy(poutbuf, poutbuf_size,
192 NULL, 0, buf, nal_size) < 0)
194 if (!ctx->first_idr && unit_type == 1)
199 cumul_size += nal_size + ctx->length_size;
200 } while (cumul_size < buf_size);
207 return AVERROR(EINVAL);
210 AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
212 sizeof(H264BSFContext),
213 h264_mp4toannexb_filter,