/* * buffered I/O * Copyright (c) 2000,2001 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/crc.h" #include "libavutil/dict.h" #include "libavutil/intreadwrite.h" #include "libavutil/log.h" #include "libavutil/opt.h" #include "libavutil/avassert.h" #include "avformat.h" #include "avio.h" #include "avio_internal.h" #include "internal.h" #include "url.h" #include <stdarg.h> #define IO_BUFFER_SIZE 32768 /** * Do seeks within this distance ahead of the current buffer by skipping * data instead of calling the protocol seek function, for seekable * protocols. */ #define SHORT_SEEK_THRESHOLD 4096 static void *ffio_url_child_next(void *obj, void *prev) { AVIOContext *s = obj; return prev ? NULL : s->opaque; } static const AVClass *ffio_url_child_class_next(const AVClass *prev) { return prev ? NULL : &ffurl_context_class; } static const AVOption ffio_url_options[] = { { NULL }, }; const AVClass ffio_url_class = { .class_name = "AVIOContext", .item_name = av_default_item_name, .version = LIBAVUTIL_VERSION_INT, .option = ffio_url_options, .child_next = ffio_url_child_next, .child_class_next = ffio_url_child_class_next, }; static void fill_buffer(AVIOContext *s); static int url_resetbuf(AVIOContext *s, int flags); int ffio_init_context(AVIOContext *s, unsigned char *buffer, int buffer_size, int write_flag, void *opaque, int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), int64_t (*seek)(void *opaque, int64_t offset, int whence)) { s->buffer = buffer; s->orig_buffer_size = s->buffer_size = buffer_size; s->buf_ptr = buffer; s->opaque = opaque; s->direct = 0; url_resetbuf(s, write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ); s->write_packet = write_packet; s->read_packet = read_packet; s->seek = seek; s->pos = 0; s->must_flush = 0; s->eof_reached = 0; s->error = 0; s->seekable = seek ? AVIO_SEEKABLE_NORMAL : 0; s->max_packet_size = 0; s->update_checksum = NULL; if (!read_packet && !write_flag) { s->pos = buffer_size; s->buf_end = s->buffer + buffer_size; } s->read_pause = NULL; s->read_seek = NULL; return 0; } AVIOContext *avio_alloc_context( unsigned char *buffer, int buffer_size, int write_flag, void *opaque, int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), int64_t (*seek)(void *opaque, int64_t offset, int whence)) { AVIOContext *s = av_mallocz(sizeof(AVIOContext)); if (!s) return NULL; ffio_init_context(s, buffer, buffer_size, write_flag, opaque, read_packet, write_packet, seek); return s; } static void writeout(AVIOContext *s, const uint8_t *data, int len) { if (s->write_packet && !s->error) { int ret = s->write_packet(s->opaque, (uint8_t *)data, len); if (ret < 0) { s->error = ret; } } s->writeout_count ++; s->pos += len; } static void flush_buffer(AVIOContext *s) { if (s->buf_ptr > s->buffer) { writeout(s, s->buffer, s->buf_ptr - s->buffer); if (s->update_checksum) { s->checksum = s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr); s->checksum_ptr = s->buffer; } } s->buf_ptr = s->buffer; } void avio_w8(AVIOContext *s, int b) { av_assert2(b>=-128 && b<=255); *s->buf_ptr++ = b; if (s->buf_ptr >= s->buf_end) flush_buffer(s); } void ffio_fill(AVIOContext *s, int b, int count) { while (count > 0) { int len = FFMIN(s->buf_end - s->buf_ptr, count); memset(s->buf_ptr, b, len); s->buf_ptr += len; if (s->buf_ptr >= s->buf_end) flush_buffer(s); count -= len; } } void avio_write(AVIOContext *s, const unsigned char *buf, int size) { if (s->direct && !s->update_checksum) { avio_flush(s); writeout(s, buf, size); return; } while (size > 0) { int len = FFMIN(s->buf_end - s->buf_ptr, size); memcpy(s->buf_ptr, buf, len); s->buf_ptr += len; if (s->buf_ptr >= s->buf_end) flush_buffer(s); buf += len; size -= len; } } void avio_flush(AVIOContext *s) { flush_buffer(s); s->must_flush = 0; } int64_t avio_seek(AVIOContext *s, int64_t offset, int whence) { int64_t offset1; int64_t pos; int force = whence & AVSEEK_FORCE; int buffer_size; whence &= ~AVSEEK_FORCE; if(!s) return AVERROR(EINVAL); buffer_size = s->buf_end - s->buffer; pos = s->pos - (s->write_flag ? 0 : buffer_size); if (whence != SEEK_CUR && whence != SEEK_SET) return AVERROR(EINVAL); if (whence == SEEK_CUR) { offset1 = pos + (s->buf_ptr - s->buffer); if (offset == 0) return offset1; offset += offset1; } offset1 = offset - pos; if (!s->must_flush && (!s->direct || !s->seek) && offset1 >= 0 && offset1 <= buffer_size) { /* can do the seek inside the buffer */ s->buf_ptr = s->buffer + offset1; } else if ((!s->seekable || offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) && !s->write_flag && offset1 >= 0 && (!s->direct || !s->seek) && (whence != SEEK_END || force)) { while(s->pos < offset && !s->eof_reached) fill_buffer(s); if (s->eof_reached) return AVERROR_EOF; s->buf_ptr = s->buf_end + offset - s->pos; } else if(!s->write_flag && offset1 < 0 && -offset1 < buffer_size>>1 && s->seek && offset > 0) { int64_t res; pos -= FFMIN(buffer_size>>1, pos); if ((res = s->seek(s->opaque, pos, SEEK_SET)) < 0) return res; s->buf_end = s->buf_ptr = s->buffer; s->pos = pos; s->eof_reached = 0; fill_buffer(s); return avio_seek(s, offset, SEEK_SET | force); } else { int64_t res; if (s->write_flag) { flush_buffer(s); s->must_flush = 1; } if (!s->seek) return AVERROR(EPIPE); if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0) return res; s->seek_count ++; if (!s->write_flag) s->buf_end = s->buffer; s->buf_ptr = s->buffer; s->pos = offset; } s->eof_reached = 0; return offset; } int64_t avio_skip(AVIOContext *s, int64_t offset) { return avio_seek(s, offset, SEEK_CUR); } int64_t avio_size(AVIOContext *s) { int64_t size; if (!s) return AVERROR(EINVAL); if (!s->seek) return AVERROR(ENOSYS); size = s->seek(s->opaque, 0, AVSEEK_SIZE); if (size < 0) { if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0) return size; size++; s->seek(s->opaque, s->pos, SEEK_SET); } return size; } int url_feof(AVIOContext *s) { if(!s) return 0; if(s->eof_reached){ s->eof_reached=0; fill_buffer(s); } return s->eof_reached; } void avio_wl32(AVIOContext *s, unsigned int val) { avio_w8(s, (uint8_t) val ); avio_w8(s, (uint8_t)(val >> 8 )); avio_w8(s, (uint8_t)(val >> 16)); avio_w8(s, val >> 24 ); } void avio_wb32(AVIOContext *s, unsigned int val) { avio_w8(s, val >> 24 ); avio_w8(s, (uint8_t)(val >> 16)); avio_w8(s, (uint8_t)(val >> 8 )); avio_w8(s, (uint8_t) val ); } int avio_put_str(AVIOContext *s, const char *str) { int len = 1; if (str) { len += strlen(str); avio_write(s, (const unsigned char *) str, len); } else avio_w8(s, 0); return len; } int avio_put_str16le(AVIOContext *s, const char *str) { const uint8_t *q = str; int ret = 0; int err = 0; while (*q) { uint32_t ch; uint16_t tmp; GET_UTF8(ch, *q++, goto invalid;) PUT_UTF16(ch, tmp, avio_wl16(s, tmp); ret += 2;) continue; invalid: av_log(s, AV_LOG_ERROR, "Invaid UTF8 sequence in avio_put_str16le\n"); err = AVERROR(EINVAL); } avio_wl16(s, 0); if (err) return err; ret += 2; return ret; } int ff_get_v_length(uint64_t val) { int i = 1; while (val >>= 7) i++; return i; } void ff_put_v(AVIOContext *bc, uint64_t val) { int i = ff_get_v_length(val); while (--i > 0) avio_w8(bc, 128 | (uint8_t)(val >> (7*i))); avio_w8(bc, val & 127); } void avio_wl64(AVIOContext *s, uint64_t val) { avio_wl32(s, (uint32_t)(val & 0xffffffff)); avio_wl32(s, (uint32_t)(val >> 32)); } void avio_wb64(AVIOContext *s, uint64_t val) { avio_wb32(s, (uint32_t)(val >> 32)); avio_wb32(s, (uint32_t)(val & 0xffffffff)); } void avio_wl16(AVIOContext *s, unsigned int val) { avio_w8(s, (uint8_t)val); avio_w8(s, (int)val >> 8); } void avio_wb16(AVIOContext *s, unsigned int val) { avio_w8(s, (int)val >> 8); avio_w8(s, (uint8_t)val); } void avio_wl24(AVIOContext *s, unsigned int val) { avio_wl16(s, val & 0xffff); avio_w8(s, (int)val >> 16); } void avio_wb24(AVIOContext *s, unsigned int val) { avio_wb16(s, (int)val >> 8); avio_w8(s, (uint8_t)val); } /* Input stream */ static void fill_buffer(AVIOContext *s) { int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE; uint8_t *dst = s->buf_end - s->buffer + max_buffer_size < s->buffer_size ? s->buf_end : s->buffer; int len = s->buffer_size - (dst - s->buffer); /* can't fill the buffer without read_packet, just set EOF if appropriate */ if (!s->read_packet && s->buf_ptr >= s->buf_end) s->eof_reached = 1; /* no need to do anything if EOF already reached */ if (s->eof_reached) return; if (s->update_checksum && dst == s->buffer) { if (s->buf_end > s->checksum_ptr) s->checksum = s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr); s->checksum_ptr = s->buffer; } /* make buffer smaller in case it ended up large after probing */ if (s->read_packet && s->orig_buffer_size && s->buffer_size > s->orig_buffer_size) { if (dst == s->buffer) { ffio_set_buf_size(s, s->orig_buffer_size); s->checksum_ptr = dst = s->buffer; } av_assert0(len >= s->orig_buffer_size); len = s->orig_buffer_size; } if (s->read_packet) len = s->read_packet(s->opaque, dst, len); else len = 0; if (len <= 0) { /* do not modify buffer if EOF reached so that a seek back can be done without rereading data */ s->eof_reached = 1; if (len < 0) s->error = len; } else { s->pos += len; s->buf_ptr = dst; s->buf_end = dst + len; s->bytes_read += len; } } unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, unsigned int len) { return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len); } unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf, unsigned int len) { return av_crc(av_crc_get_table(AV_CRC_16_ANSI_LE), checksum, buf, len); } unsigned long ffio_get_checksum(AVIOContext *s) { s->checksum = s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr); s->update_checksum = NULL; return s->checksum; } void ffio_init_checksum(AVIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum) { s->update_checksum = update_checksum; if (s->update_checksum) { s->checksum = checksum; s->checksum_ptr = s->buf_ptr; } } /* XXX: put an inline version */ int avio_r8(AVIOContext *s) { if (s->buf_ptr >= s->buf_end) fill_buffer(s); if (s->buf_ptr < s->buf_end) return *s->buf_ptr++; return 0; } int avio_read(AVIOContext *s, unsigned char *buf, int size) { int len, size1; size1 = size; while (size > 0) { len = s->buf_end - s->buf_ptr; if (len > size) len = size; if (len == 0 || s->write_flag) { if((s->direct || size > s->buffer_size) && !s->update_checksum){ if(s->read_packet) len = s->read_packet(s->opaque, buf, size); if (len <= 0) { /* do not modify buffer if EOF reached so that a seek back can be done without rereading data */ s->eof_reached = 1; if(len<0) s->error= len; break; } else { s->pos += len; s->bytes_read += len; size -= len; buf += len; s->buf_ptr = s->buffer; s->buf_end = s->buffer/* + len*/; } } else { fill_buffer(s); len = s->buf_end - s->buf_ptr; if (len == 0) break; } } else { memcpy(buf, s->buf_ptr, len); buf += len; s->buf_ptr += len; size -= len; } } if (size1 == size) { if (s->error) return s->error; if (url_feof(s)) return AVERROR_EOF; } return size1 - size; } int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data) { if (s->buf_end - s->buf_ptr >= size && !s->write_flag) { *data = s->buf_ptr; s->buf_ptr += size; return size; } else { *data = buf; return avio_read(s, buf, size); } } int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size) { int len; if (size < 0) return -1; if (s->read_packet && s->write_flag) { len = s->read_packet(s->opaque, buf, size); if (len > 0) s->pos += len; return len; } len = s->buf_end - s->buf_ptr; if (len == 0) { /* Reset the buf_end pointer to the start of the buffer, to make sure * the fill_buffer call tries to read as much data as fits into the * full buffer, instead of just what space is left after buf_end. * This avoids returning partial packets at the end of the buffer, * for packet based inputs. */ s->buf_end = s->buf_ptr = s->buffer; fill_buffer(s); len = s->buf_end - s->buf_ptr; } if (len > size) len = size; memcpy(buf, s->buf_ptr, len); s->buf_ptr += len; if (!len) { if (s->error) return s->error; if (url_feof(s)) return AVERROR_EOF; } return len; } unsigned int avio_rl16(AVIOContext *s) { unsigned int val; val = avio_r8(s); val |= avio_r8(s) << 8; return val; } unsigned int avio_rl24(AVIOContext *s) { unsigned int val; val = avio_rl16(s); val |= avio_r8(s) << 16; return val; } unsigned int avio_rl32(AVIOContext *s) { unsigned int val; val = avio_rl16(s); val |= avio_rl16(s) << 16; return val; } uint64_t avio_rl64(AVIOContext *s) { uint64_t val; val = (uint64_t)avio_rl32(s); val |= (uint64_t)avio_rl32(s) << 32; return val; } unsigned int avio_rb16(AVIOContext *s) { unsigned int val; val = avio_r8(s) << 8; val |= avio_r8(s); return val; } unsigned int avio_rb24(AVIOContext *s) { unsigned int val; val = avio_rb16(s) << 8; val |= avio_r8(s); return val; } unsigned int avio_rb32(AVIOContext *s) { unsigned int val; val = avio_rb16(s) << 16; val |= avio_rb16(s); return val; } int ff_get_line(AVIOContext *s, char *buf, int maxlen) { int i = 0; char c; do { c = avio_r8(s); if (c && i < maxlen-1) buf[i++] = c; } while (c != '\n' && c); buf[i] = 0; return i; } int avio_get_str(AVIOContext *s, int maxlen, char *buf, int buflen) { int i; if (buflen <= 0) return AVERROR(EINVAL); // reserve 1 byte for terminating 0 buflen = FFMIN(buflen - 1, maxlen); for (i = 0; i < buflen; i++) if (!(buf[i] = avio_r8(s))) return i + 1; buf[i] = 0; for (; i < maxlen; i++) if (!avio_r8(s)) return i + 1; return maxlen; } #define GET_STR16(type, read) \ int avio_get_str16 ##type(AVIOContext *pb, int maxlen, char *buf, int buflen)\ {\ char* q = buf;\ int ret = 0;\ if (buflen <= 0) \ return AVERROR(EINVAL); \ while (ret + 1 < maxlen) {\ uint8_t tmp;\ uint32_t ch;\ GET_UTF16(ch, (ret += 2) <= maxlen ? read(pb) : 0, break;)\ if (!ch)\ break;\ PUT_UTF8(ch, tmp, if (q - buf < buflen - 1) *q++ = tmp;)\ }\ *q = 0;\ return ret;\ }\ GET_STR16(le, avio_rl16) GET_STR16(be, avio_rb16) #undef GET_STR16 uint64_t avio_rb64(AVIOContext *s) { uint64_t val; val = (uint64_t)avio_rb32(s) << 32; val |= (uint64_t)avio_rb32(s); return val; } uint64_t ffio_read_varlen(AVIOContext *bc){ uint64_t val = 0; int tmp; do{ tmp = avio_r8(bc); val= (val<<7) + (tmp&127); }while(tmp&128); return val; } int ffio_fdopen(AVIOContext **s, URLContext *h) { uint8_t *buffer; int buffer_size, max_packet_size; max_packet_size = h->max_packet_size; if (max_packet_size) { buffer_size = max_packet_size; /* no need to bufferize more than one packet */ } else { buffer_size = IO_BUFFER_SIZE; } buffer = av_malloc(buffer_size); if (!buffer) return AVERROR(ENOMEM); *s = avio_alloc_context(buffer, buffer_size, h->flags & AVIO_FLAG_WRITE, h, (void*)ffurl_read, (void*)ffurl_write, (void*)ffurl_seek); if (!*s) { av_free(buffer); return AVERROR(ENOMEM); } (*s)->direct = h->flags & AVIO_FLAG_DIRECT; (*s)->seekable = h->is_streamed ? 0 : AVIO_SEEKABLE_NORMAL; (*s)->max_packet_size = max_packet_size; if(h->prot) { (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause; (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek; } (*s)->av_class = &ffio_url_class; return 0; } int ffio_ensure_seekback(AVIOContext *s, int buf_size) { uint8_t *buffer; int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE; int filled = s->buf_end - s->buffer; buf_size += s->buf_ptr - s->buffer + max_buffer_size; if (buf_size < filled || s->seekable) return 0; av_assert0(!s->write_flag); buffer = av_malloc(buf_size); if (!buffer) return AVERROR(ENOMEM); memcpy(buffer, s->buffer, filled); av_free(s->buffer); s->buf_ptr = buffer + (s->buf_ptr - s->buffer); s->buf_end = buffer + (s->buf_end - s->buffer); s->buffer = buffer; s->buffer_size = buf_size; return 0; } int ffio_set_buf_size(AVIOContext *s, int buf_size) { uint8_t *buffer; buffer = av_malloc(buf_size); if (!buffer) return AVERROR(ENOMEM); av_free(s->buffer); s->buffer = buffer; s->orig_buffer_size = s->buffer_size = buf_size; s->buf_ptr = buffer; url_resetbuf(s, s->write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ); return 0; } static int url_resetbuf(AVIOContext *s, int flags) { av_assert1(flags == AVIO_FLAG_WRITE || flags == AVIO_FLAG_READ); if (flags & AVIO_FLAG_WRITE) { s->buf_end = s->buffer + s->buffer_size; s->write_flag = 1; } else { s->buf_end = s->buffer; s->write_flag = 0; } return 0; } int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char **bufp, int buf_size) { int64_t buffer_start; int buffer_size; int overlap, new_size, alloc_size; uint8_t *buf = *bufp; if (s->write_flag) { av_freep(bufp); return AVERROR(EINVAL); } buffer_size = s->buf_end - s->buffer; /* the buffers must touch or overlap */ if ((buffer_start = s->pos - buffer_size) > buf_size) { av_freep(bufp); return AVERROR(EINVAL); } overlap = buf_size - buffer_start; new_size = buf_size + buffer_size - overlap; alloc_size = FFMAX(s->buffer_size, new_size); if (alloc_size > buf_size) if (!(buf = (*bufp) = av_realloc_f(buf, 1, alloc_size))) return AVERROR(ENOMEM); if (new_size > buf_size) { memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap); buf_size = new_size; } av_free(s->buffer); s->buf_ptr = s->buffer = buf; s->buffer_size = alloc_size; s->pos = buf_size; s->buf_end = s->buf_ptr + buf_size; s->eof_reached = 0; s->must_flush = 0; return 0; } int avio_open(AVIOContext **s, const char *filename, int flags) { return avio_open2(s, filename, flags, NULL, NULL); } int avio_open2(AVIOContext **s, const char *filename, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options) { URLContext *h; int err; err = ffurl_open(&h, filename, flags, int_cb, options); if (err < 0) return err; err = ffio_fdopen(s, h); if (err < 0) { ffurl_close(h); return err; } return 0; } int avio_close(AVIOContext *s) { URLContext *h; if (!s) return 0; avio_flush(s); h = s->opaque; av_freep(&s->buffer); if (s->write_flag) av_log(s, AV_LOG_DEBUG, "Statistics: %d seeks, %d writeouts\n", s->seek_count, s->writeout_count); else av_log(s, AV_LOG_DEBUG, "Statistics: %"PRId64" bytes read, %d seeks\n", s->bytes_read, s->seek_count); av_free(s); return ffurl_close(h); } int avio_closep(AVIOContext **s) { int ret = avio_close(*s); *s = NULL; return ret; } int avio_printf(AVIOContext *s, const char *fmt, ...) { va_list ap; char buf[4096]; int ret; va_start(ap, fmt); ret = vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap); avio_write(s, buf, strlen(buf)); return ret; } int avio_pause(AVIOContext *s, int pause) { if (!s->read_pause) return AVERROR(ENOSYS); return s->read_pause(s->opaque, pause); } int64_t avio_seek_time(AVIOContext *s, int stream_index, int64_t timestamp, int flags) { URLContext *h = s->opaque; int64_t ret; if (!s->read_seek) return AVERROR(ENOSYS); ret = s->read_seek(h, stream_index, timestamp, flags); if (ret >= 0) { int64_t pos; s->buf_ptr = s->buf_end; // Flush buffer pos = s->seek(h, 0, SEEK_CUR); if (pos >= 0) s->pos = pos; else if (pos != AVERROR(ENOSYS)) ret = pos; } return ret; } /* output in a dynamic buffer */ typedef struct DynBuffer { int pos, size, allocated_size; uint8_t *buffer; int io_buffer_size; uint8_t io_buffer[1]; } DynBuffer; static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size) { DynBuffer *d = opaque; unsigned new_size, new_allocated_size; /* reallocate buffer if needed */ new_size = d->pos + buf_size; new_allocated_size = d->allocated_size; if (new_size < d->pos || new_size > INT_MAX/2) return -1; while (new_size > new_allocated_size) { if (!new_allocated_size) new_allocated_size = new_size; else new_allocated_size += new_allocated_size / 2 + 1; } if (new_allocated_size > d->allocated_size) { int err; if ((err = av_reallocp(&d->buffer, new_allocated_size)) < 0) { d->allocated_size = 0; d->size = 0; return err; } d->allocated_size = new_allocated_size; } memcpy(d->buffer + d->pos, buf, buf_size); d->pos = new_size; if (d->pos > d->size) d->size = d->pos; return buf_size; } static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size) { unsigned char buf1[4]; int ret; /* packetized write: output the header */ AV_WB32(buf1, buf_size); ret = dyn_buf_write(opaque, buf1, 4); if (ret < 0) return ret; /* then the data */ return dyn_buf_write(opaque, buf, buf_size); } static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence) { DynBuffer *d = opaque; if (whence == SEEK_CUR) offset += d->pos; else if (whence == SEEK_END) offset += d->size; if (offset < 0 || offset > 0x7fffffffLL) return -1; d->pos = offset; return 0; } static int url_open_dyn_buf_internal(AVIOContext **s, int max_packet_size) { DynBuffer *d; unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024; if (sizeof(DynBuffer) + io_buffer_size < io_buffer_size) return -1; d = av_mallocz(sizeof(DynBuffer) + io_buffer_size); if (!d) return AVERROR(ENOMEM); d->io_buffer_size = io_buffer_size; *s = avio_alloc_context(d->io_buffer, d->io_buffer_size, 1, d, NULL, max_packet_size ? dyn_packet_buf_write : dyn_buf_write, max_packet_size ? NULL : dyn_buf_seek); if(!*s) { av_free(d); return AVERROR(ENOMEM); } (*s)->max_packet_size = max_packet_size; return 0; } int avio_open_dyn_buf(AVIOContext **s) { return url_open_dyn_buf_internal(s, 0); } int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size) { if (max_packet_size <= 0) return -1; return url_open_dyn_buf_internal(s, max_packet_size); } int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer) { DynBuffer *d; int size; static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0}; int padding = 0; if (!s) { *pbuffer = NULL; return 0; } d = s->opaque; /* don't attempt to pad fixed-size packet buffers */ if (!s->max_packet_size) { avio_write(s, padbuf, sizeof(padbuf)); padding = FF_INPUT_BUFFER_PADDING_SIZE; } avio_flush(s); *pbuffer = d->buffer; size = d->size; av_free(d); av_free(s); return size - padding; } static int null_buf_write(void *opaque, uint8_t *buf, int buf_size) { DynBuffer *d = opaque; d->pos += buf_size; if (d->pos > d->size) d->size = d->pos; return buf_size; } int ffio_open_null_buf(AVIOContext **s) { int ret = url_open_dyn_buf_internal(s, 0); if (ret >= 0) { AVIOContext *pb = *s; pb->write_packet = null_buf_write; } return ret; } int ffio_close_null_buf(AVIOContext *s) { DynBuffer *d = s->opaque; int size; avio_flush(s); size = d->size; av_free(d); av_free(s); return size; }