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) {
37 uint32_t offset = *poutbuf_size;
38 uint8_t nal_header_size = offset ? 3 : 4;
41 *poutbuf_size += sps_pps_size+in_size+nal_header_size;
42 tmp = av_realloc(*poutbuf, *poutbuf_size);
44 return AVERROR(ENOMEM);
47 memcpy(*poutbuf+offset, sps_pps, sps_pps_size);
48 memcpy(*poutbuf+sps_pps_size+nal_header_size+offset, in, in_size);
50 AV_WB32(*poutbuf+sps_pps_size, 1);
52 (*poutbuf+offset+sps_pps_size)[0] = (*poutbuf+offset+sps_pps_size)[1] = 0;
53 (*poutbuf+offset+sps_pps_size)[2] = 1;
59 static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
60 AVCodecContext *avctx, const char *args,
61 uint8_t **poutbuf, int *poutbuf_size,
62 const uint8_t *buf, int buf_size,
64 H264BSFContext *ctx = bsfc->priv_data;
67 uint32_t cumul_size = 0;
68 const uint8_t *buf_end = buf + buf_size;
70 /* nothing to filter */
71 if (!avctx->extradata || avctx->extradata_size < 6) {
72 *poutbuf = (uint8_t*) buf;
73 *poutbuf_size = buf_size;
77 /* retrieve sps and pps NAL units from extradata */
78 if (!ctx->extradata_parsed) {
80 uint64_t total_size = 0;
81 uint8_t *out = NULL, unit_nb, sps_done = 0, sps_seen = 0, pps_seen = 0;
82 const uint8_t *extradata = avctx->extradata+4;
83 static const uint8_t nalu_header[4] = {0, 0, 0, 1};
85 /* retrieve length coded size */
86 ctx->length_size = (*extradata++ & 0x3) + 1;
87 if (ctx->length_size == 3)
88 return AVERROR(EINVAL);
90 /* retrieve sps and pps unit(s) */
91 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
93 unit_nb = *extradata++; /* number of pps unit(s) */
105 unit_size = AV_RB16(extradata);
106 total_size += unit_size+4;
107 if (total_size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE ||
108 extradata+2+unit_size > avctx->extradata+avctx->extradata_size) {
110 return AVERROR(EINVAL);
112 tmp = av_realloc(out, total_size + FF_INPUT_BUFFER_PADDING_SIZE);
115 return AVERROR(ENOMEM);
118 memcpy(out+total_size-unit_size-4, nalu_header, 4);
119 memcpy(out+total_size-unit_size, extradata+2, unit_size);
120 extradata += 2+unit_size;
122 if (!unit_nb && !sps_done++) {
123 unit_nb = *extradata++; /* number of pps unit(s) */
130 memset(out + total_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
133 av_log(avctx, AV_LOG_WARNING, "Warning: SPS NALU missing or invalid. The resulting stream may not play.\n");
135 av_log(avctx, AV_LOG_WARNING, "Warning: PPS NALU missing or invalid. The resulting stream may not play.\n");
137 av_free(avctx->extradata);
138 avctx->extradata = out;
139 avctx->extradata_size = total_size;
141 ctx->extradata_parsed = 1;
147 if (buf + ctx->length_size > buf_end)
150 if (ctx->length_size == 1) {
152 } else if (ctx->length_size == 2) {
153 nal_size = AV_RB16(buf);
155 nal_size = AV_RB32(buf);
157 buf += ctx->length_size;
158 unit_type = *buf & 0x1f;
160 if (buf + nal_size > buf_end || nal_size < 0)
163 /* prepend only to the first type 5 NAL unit of an IDR picture */
164 if (ctx->first_idr && unit_type == 5) {
165 if (alloc_and_copy(poutbuf, poutbuf_size,
166 avctx->extradata, avctx->extradata_size,
171 if (alloc_and_copy(poutbuf, poutbuf_size,
175 if (!ctx->first_idr && unit_type == 1)
180 cumul_size += nal_size + ctx->length_size;
181 } while (cumul_size < buf_size);
188 return AVERROR(EINVAL);
191 AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
193 sizeof(H264BSFContext),
194 h264_mp4toannexb_filter,